Synthesis of water-soluble large naturalised dyes through double glycoconjugation

FULL PAPER

DOI: 10.1002/ejoc.200801302

Synthesis of Water-Soluble Large Naturalised Dyes Through Double

Glycoconjugation

Jalal Isaad,^[a]Massimo Rolla,^[a]and Roberto Bianchini*^[a]

Keywords: Azo compounds / Dyes/Pigments / Quinones / Carbohydrates / Glycoconjugation

Recently we started to develop a new class of dyes based

upon the glycoconjugation of disperse dyes with mono- or

disaccharides. We used the term “naturalised” to describe

these dyes because we used natural lactose in the glycocon-

jugation process, and also because they are similar to real

natural dyes, the hydrosolubility of which is based upon the

saccharidic moiety attached to the chromophore, as in carm-

inic acid or carthamin. Synthetic dyes submitted to the pro-

cess of naturalisation consist of small chromophoric mole-

cules, prevalently azoic, whereas larger dye molecules with

a higher mass did not show appreciable solubility in water

when a single molecule of lactose was added through a bi-

valent spacer, which is in contrast to the smaller dyes. To

overcome this difficulty, herein we present the first approach

to the insertion of two lactose units by a double glycoconjug-

ation process. The procedure here presented allows the suc-

cessful insertion of a spacer, the malonic acid, which can be

linked with two lactose units so that even large dyes become

soluble.

Germany, 2009)

ment, and this is not an easy task because whatever technol-

ogy is adopted,^[2]for example, chemical or electrochemical

oxidation, membrane technology, chemical precipitation,

photocatalytic degradation and adsorption or electrosorp-

tion onto various adsorbents, the costs are prohibitive.

Furthermore, the rinsing that is required to remove surfac-

tants from clothes once dyed because of the danger to hu-

man health,^[4,5]creates a significant quantity of waste water.

We could take into consideration many other factors, but it

can be concluded that the textile industry needs to make

many changes, particularly with respect to the dyeing pro-

cesses, materials and waste treatment.

In an attempt to reduce the environmental impact of the

dyeing process and to improve the performances of the ma-

terials and procedures involved, we have recently developed

a new class of dyes, which we have named “naturalised

dyes”^[6]that do not require chemical additives during the

dyeing process, enable dyeing to be performed at lower tem-

peratures and in a shorter time, and are multipurpose, with

each of them able to dye different fibres, be they natural,

artificial or synthetic.

Introduction

Disperse dyes, still very important in the dyeing of many

materials, consist mainly of azo and anthraquinonic chro-

mophores and are essentially insoluble in water, in which

they form a dispersion.^[1]The process of dyeing synthetic

fabrics, like polyester, acetate, acrylic and polyamide, be-

comes possible by adding liquors and surface agents. Con-

sequently they are able to approach the hydrophobic fibres

with which they have an affinity, and to dye them. But the

use of these materials raises some concern because of the

considerable quantities of additives that are necessary for

dyeing in water. Moreover, the environmental impact both

of the dyes and of the additives cannot be neglected. The

textile industry consumes high percentages of the total sur-

factant production,^[2]which causes considerable difficulties

in purification plants as the elimination of surfactants is

difficult. In fact, biological treatment, especially under aero-

bic aqueous conditions, is not easy in their presence. Under

anaerobic conditions surfactants are not biodegradable and

therefore they remain in solution affecting aquatic life. The

synergistic effect with other toxic chemicals that may be

present in waste waters increases their negative effects on

the environment.^[3]In this context, the surfactants present

in the waste waters of textile industries must be reduced to

acceptable levels before being discharged into the environ-

We started with the glycoconjugation of synthetic dyes

because saccharidic moieties are found in natural com-

pounds. For instance, carthamin^[7](Figure 1) is a natural

red double-glycoconjugated pigment derived from safflower

(Carthamus tinctorius).

Safflower has been cultivated since ancient times and was

used as a dye in ancient Egypt^[8]and later in European

countries, where it was used extensively for dyeing wool and

in the carpet industry. Note that carthamin is highly hydro-

[a] Dipartimento di Chimica Organica “Ugo Schiff”, Università di

Firenze,

Via della Lastruccia 13, 50019 Sesto Fiorentino (FI), Italy

Fax: +39-0554573531

E-mail: roberto.bianchini@unifi.it

2748

Eur. J. Org. Chem. 2009, 2748–2764

Synthesis of Water-Soluble Large Naturalised Dyes

each displayed all the properties characteristic of natural-

ised dyes.

Figure 1. The structure of carthamin that includes twosaccharidic

molecules.

philic and this is the most important characteristic that we

propose to transfer to (or improve on in) commercial or

synthetic dyes. Carthamin also attracted our attention be-

cause the chromophore is large and even though many po-

lar groups, for example, hydroxys and carbonyls, are pres-

ent, the two units of saccharide are covalently bonded to it

to render it water-soluble. The results of a correlated, con-

temporary study of this compound have been reported in

the literature.^[9]

Figure 2. The commercial dyes used for the double glycoconjug-

ation procedure.

The synthetic path depends on the nature and the posi-

tion of the functional group in the starting molecules. Start-

ing with D1, we prepared first the diethereal derivative ac-

cording to a recently proposed procedure^[12]and obtained

the naturalised ethereal lactosidic derivative NatD1-eth

(Scheme 1). This derivative was not soluble in water, insen-

sitive to warming, stirring, powdering and microwaving. All

attempts to solubilise it led to two-phase systems, with the

water phase almost completely clear and uncoloured.

As described in our previous papers, we proceeded to

glycoconjugate the azo dyes with lactose or with its monos-

accharidic components, glucose and galactose, through es-

ter^[10,11]or ether^[12,13]spacers bonded between the glyco-

sidic moiety and the dye. The different glycol-azo dyes

(GADs) synthesised are soluble in water and are multipur-

pose as they dye all the fabrics that we tested: wool, silk,

nylon, polyester, acrylic and acetate. In the case of cotton,

the results were contradictory. The dyeing process with

these GADs was carried out in water without additives and

under mild conditions of temperature and pressure.

The limitation of this procedure is that it is effective for

small molecules, with molecular weights not larger than

250–300; difficulties arose with larger dyes. To overcome

these difficulties, we decided to perform a more extensive

glycoconjugation using other alternatives described in a

European patent recently submitted. These approaches in-

volve either the use of glutamic acid as the bridge with two

acid units remaining free to bond with two lactose units or

the preparation of a unique saccharidic moiety formed from

two molecules of lactose covalently bonded.^[14]Herein we

present another approach that produces results in accord

with our expectations. We proceeded therefore to prepare

double-conjugated compounds using malonic acid deriva-

tives as the spacer.

Scheme 1. Preparation of the diethereal glycoconjugated derivative

of D1. Reagents and conditions: a) dibromopentane, KOH, 18-

crown-6, room temp., 67 %; b) derivative 7, KOH, 18-crown-6.

room temp., 54%; c) TFA, room temp., 3 h, 94%.

Owing to this failure, we tried a more extensive glycocon-

jugation of the dye D1, hoping that with a different lipo-

philic dye/hydrophilic lactose ratio the dye would become

soluble in water and multipurpose as far as its tinctorial

ability is concerned.

The required naturalised dye NatD1-b was obtained from

the bis-azo dye D1 by using diethyl chloromalonate as the

spacer directly bonded to the aromatic hydroxy group of

D1. The phenolic group of D1 was treated with diethyl

chloromalonate in THF and sodium hydride at room tem-

Results and Discussion

Coupling of the Starting Dyes D1–5

Five different commercial dyes (Figure 2) were selected perature to afford D1Ј, this step was followed by saponifica-

for the double glycoconjugation procedure, after which they tion with potassium hydroxide in a water/1,4-dioxane mix-

Eur. J. Org. Chem. 2009, 2748–2764

www.eurjoc.org

2749

J. Isaad, M. Rolla, R. Bianchini

FULL PAPER

ture to provide the corresponding diacid D1ЈЈ. Next, the The same procedure was applied to NatD1-bp to give the

diacid D1ЈЈ was coupled with the protected amino-lactose double-glycoconjugated NatD1-b.

7 (Scheme 2).

Finally, the mixed glycoconjugated product NatD1mx

was prepared in which the protected amino-galactose 8^[14a]

was attached to the other acid functionality of the malonic

unit of NatD1-mp (Scheme 4).

Scheme 2. Preparation of the mono- and double-conjugated natu-

ralised dye D1 depending on the stoichiometry of 7. Reagents and

conditions: a) NaH, THF, 0 °C to room temp. 20 h, 82%; b) KOH,

dioxane/water (1:1), room temp., 2 h, 96%; c) NMM, DMTMM,

THF, amino-lactose derivative 7, room temp., 20 h, 77 % for

NatD1-mp and 92% for NatD1-bp.

Scheme 4. Preparation of mixed NatD1mx from NatD1-mp. Rea-

gents and conditions: a) DMTMM, NMM, galactosamine 8,^[14a]

THF, room temp., 20 h, 67%; b) TFA, room temp., 4 h, 95%.

During the coupling of the diacid D1ЈЈ and the glycide

With all these derivatives of the starting dye D1, we can

7, the activated acid intermediate can be attacked by one or compare their solubility in water and their glycidic content

two molecules of amino-lactose derivative 7. With 1 equiv. (Table 1).

of 7, the mono-glycoconjugated derivative NatD1-mp was

formed, but with 2 equiv. of 7, the product consists of a eth are insoluble in water; the solubility starts with product

double-glycoconjugated derivative NatD1-bp. NatD1mx and is immediate with NatD1-b. Therefore we

We have to realise that products NatD1-m and NatD1-

The final mono-glycoconjugated naturalised dye NatD1- can conclude that for these derivatives to be soluble, a mini-

m was obtained after deprotection of the NatD1-mp in TFA mum percentage weight of 50% of the glycidic moiety is

at room temperature as an anomeric mixture (Scheme 3). required, whereas at 40% they are completely insoluble.

Scheme 3. Deprotection of the compounds NatD1-mp and NatD1-bp to give the final products NatD1-m and NatD1-b. Reagents and

conditions: a) TFA, room temp., 3 h, 98%.

2750

www.eurjoc.org

Eur. J. Org. Chem. 2009, 2748–2764

Synthesis of Water-Soluble Large Naturalised Dyes

Table 1. Formulae of the naturalised derivatives of the dye D1 and the molecular weights of their lipophilic (chromophore and spacer)

and glycidic moieties (saccharide) and their molecular weight ratios and solubility.

Naturalized dye

Chromophore

(formula weight) weight)

Spacer (formula Saccharide (formula MW [g/mol]

Ratio saccharide/

MW [%]

Solubility^[a][g/L]

weight)

NatD1-m

NatD1-eth

NatD1mx

NatD1-b

C₁₉H₁₄N₅O₄

376.36

C₁₉H₁₄N₅O₄

376.36

C₁₉H₁₄N₅O₄

376.36

C₁₉H₁₄N₅O₄

376.36

C₃H₄NO₃

101.067

C₅H₁₀O₂

102.135

C₃H₄NO₃

101.067

C₁₂H₂₀O₁₀

324.292

C₁₂H₂₀O₁₀

324.292

C₁₈H₃₂O₁₅

488.454

C₂₄H₄₀O₂₀

648.584

C₃₄H₃₈N₆O₁₇

801.71

C₃₆H₄₄N₅O₁₆

803.79

C₄₀H₄₉N₇O₂₁

962.88

C₄₆H₅₈N₆O₂₇

1124.01

40.4

40.5

50.7

57.7

Insoluble

69.34

C₃H₄NO₃

101.067

71.47

[a] The solubility was measured at room temperature.

Synthesis of the Amino Lactose 7 and Amino Galactose 8

Protected Derivatives

The protected amino-galactose 8 was prepared according

to the literature^[15a]starting from commercial 1,2:3,4-bis-O-

(1-methylethylidene)-α--galactopyranose.

The protected amino-lactose 7 was obtained in four fac-

ile steps and 55% overall isolated yield from α,-lactose

2 following the procedure reported in the literature^[15a,15b]

(Scheme 5). First, we treated α,-lactose 2 with dimeth-

Naturalisation of a Representative Anthraquinonic Dye

Anthraquinonic D2 is a well-known textile disperse dye

oxypropane according to the reported procedure^[16]to ob- that is insoluble in water. Thus, dyeing processes involving

tain a mixture of the protected lactoses 3 (R = H) and 4 (R D2 are carried out in the presence of surface agents that

= MIP). We then selectively deprotected the MIP group of bring the dye into contact with the surface of the liquid

3 in the mixture by using H₂O/MeOH (1:10) at 80 °C, which phase, from where it is distributed onto the fabric, often a

fully transformed 3 into the protected product 4 in which synthetic material. Of course, the quantity of surface agents

the OH in the 6Ј-position was free. Subsequently, regioselec- is considerable, in large excess with respect to the dye itself,

tive tosylation of the primary 6Ј-OH group in 4 with p- and the treatment of waste water raises difficult problems.

toluenesulfonyl chloride in the presence of pyridine/acetoni- Moreover, the use of surface agents makes necessary many

trile (2:1) gave the 6Ј-tosyl derivative 5. In turn, derivative washes, therefore increasing water consumption. Because of

5 was treated with an excess of sodium azide in DMSO at all these problems, we wondered whether naturalisation of

100 °C to provide the 6Ј-azide-protected lactose 6, which the D2 dye was possible.

was transformed into 7 by hydrogenation on 10% Pd/C in

Because the presence of the amino group on the anthra-

methanol (Scheme 5).

quinonic ring could interfere with the following chemistry,

Scheme 5. Conversion of lactose 2 into the 6Ј-amino-protected lactose 7. Reagents and conditions: a) DMP, TsOH, 80 °C, 5 h; b) H₂O/

MeOH (1:10), 1.5 h, 80 °C, 95%; c) TsCl, pyridine/acetonitrile (2:1), room temp., 24 h, 82%; d) NaN₃, DMSO, 90 °C, 20 h, 81%; e) H₂,

10% Pd/C, MeOH, 96%.

Eur. J. Org. Chem. 2009, 2748–2764

www.eurjoc.org

2751

J. Isaad, M. Rolla, R. Bianchini

FULL PAPER

we decided first to introduce a benzoyl group onto the NH₂initial D2, as two auxochromes of the anthraquinone deriv-

group (Scheme 6). Without benzoylation of the amino ative chromophore, the NH₂and OH groups, have been

group, D2 did not react to give D2-Eth, even under harsher modified.

reaction conditions and longer reaction times. After prepar-

ing D2-Bz, we tried to attach the malonate diethyl ester

directly onto the hydroxy group on the anthraquinone by

using 2-bromo- or 2-chloro derivatives of the malonic dies-

Naturalisation of Azo Dyes

ter under basic or extremely basic conditions, but all our

The first problem concerning the solubilisation in water

attempts were unsuccessful. Thus, we attempted a longer of heavy disperse dyes through a double glycoconjugation

strategy that involved the preparation of the ethereal deriva- can be considered satisfied, but still the other decisive ques-

tive D2-Eth using 1,5-dibromopentane and K₂CO₃in ace- tion about the ability to dye different fabrics with these

tone at reflux. D2-Eth was easily obtained and from this we double-lactose-conjugated derivatives remains unanswered.

arrived at the D2-mal adduct by using THF as the solvent, Therefore, we decided to compare these derivatives with

NaH as the base and diethyl malonate as the reagent. We those obtained through a single glycoconjugation, through

proceeded then to saponify the diethyl ester of the malonate which a multipurpose dye has been obtained and tested.

derivative and finally we isolated the diacid derivative after

We started with the naturalisation of the dye family bear-

treatment with mineral acid. D2-ac was then treated with ing a nitrile group (D3), which will be glycoconjugated for

amino-lactose 7 in the presence of either coupling reagent the first time. For this purpose, we synthesised the diethyl

to arrive at the protected naturalised NatD2-p product. The 2-(2-aminoethyl)malonate (12) in order to use its amino

final step was the deprotection of this last compound using group in the coupling step with an eventual carboxylic acid

TFA, as already described, and finally we isolated NatD2 deriving from the hydrolysis of the nitrile group of the dye

in good yield. This product was readily soluble in water, D3. The malonate derivative 12 was prepared as shown in

even though we have introduced two spacers one of which Scheme 7 from 2-chloroethanamine (9). First, we protected

is and lipophilic. However, the influence of the two lactose the amino group of 9 following the Boc strategy to yield

units in the naturalised NatD2 raises the molecular weight 10 quantitatively. The N-Boc-2-chloroethanamine (10) was

of the hydrophilic moieties to 58.5% (see Table 1), a crucial condensed with diethyl malonate diester in THF in the

value in terms of water solubility, as stressed above. Here, presence of the sodium hydride as base at reflux to give 11

at variance with the azo dyes so far considered, we note in a high yield. The derivative 11 was eventually deprotected

that NatD2 displays a different colour with respect to the in 90% TFA to provide 12 in three steps from 9.

Scheme 6. Naturalisation of the anthraquinonic D2. Reagents and conditions: a) benzoyl chloride, pyridine, 0 °C to room temp., 88%;

b) 1,5-dibromopentane, K₂CO₃, acetone, reflux, 20 h, 74%; c) diethyl malonate, NaH, THF, reflux, 20 h, 88%; d) KOH, dioxane/water,

room temp., 97%; e) DMTMM, NMM, lactose derivative 7, THF, room temp., 20 h, 97%.; f) TFA, room temp., 4 h, 98%.

2752

www.eurjoc.org

Eur. J. Org. Chem. 2009, 2748–2764

Synthesis of Water-Soluble Large Naturalised Dyes

Scheme 7. Reagents and conditions: a) (Boc)₂O, NaHCO₃, 1,4-dioxane/H₂O, 0 °C to room temp. 18 h, 97%; b) diethyl malonate diester,

NaH, THF, reflux, 18 h, 84%; (c) TFA, –15 °C, 3 h, then NH₄OH, 91%.

The first step of the derivatisation of D3 was the attack

on the nitrile group with 37% HCl at 90 °C to give the

corresponding carboxylic acid D3-ac in quantitative yield

(Scheme 8). D3-mal was then obtained from a coupling be-

tween the acid D3-ac and the malonate derivative 11 in

THF as solvent under basic conditions at room temperature

using either of two different coupling agents (see Table 2).

The diethyl ester malonate derivative D3-mal was then sub-

mitted to saponification to produce the diacid derivative

D3-diac. This was finally coupled with the 6Ј-amino-lactose

7 to produce NatD3-p using the coupling reagent 4-(4,6-

dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chlo-

Scheme 9. Synthesis of NatD3 from NatD3-p. Reagents and condi-

tions: a) TFA, room temp., 4 h, 99%.

ride (DMTMM; see below for a discussion on the use of

coupling reagents). NatD3-p is the expected naturalised de-

As far as the other two azoic dyes are concerned, we

rivative of the starting dye, still protected.

naturalised the dyes D4 and D5 using ethereal linkages, pro-

The deprotection step, illustrated in Scheme 9, carried duced by the reaction of the hydroxy group of the dyes with

out in the presence of TFA as usual, gave NatD3 as the 1,5-dibromopentane, as for the D2 dye, which gave D4-eth

product.

and D5-eth, respectively. Nucleophilic substitution of the

Scheme 8. Synthesis of protected naturalised compound NatD3-p starting from the nitrile derivative D3. Reagents and conditions: a)

37% HCl, acetic acid, 90 °C, 3 h, 98%; b) derivative 11, ethyl chloroformate, NEt₃, 20 h, 89%; c) KOH, dioxane/water, room temp., 98%;

d) DMTMM, NMM, lactose derivative 7, THF, room temp., 20 h, 92%.

Eur. J. Org. Chem. 2009, 2748–2764

www.eurjoc.org

2753

J. Isaad, M. Rolla, R. Bianchini

FULL PAPER

Scheme 10. Naturalisation process for the dyes D4 and D5. Reagents and conditions: a) 1,5-dibromopentane, KOH, 18-crown-6, THF,

room temp., 20 h, 78%; b) diethyl malonate, NaH, THF, reflux, 20 h, 89%; c) KOH, dioxane/water, room temp., 93%; d) DMTMM,

NMM, lactose derivative 7, THF, room temp., 97%; e) TFA, room temp., 4 h, 98%.

remaining bromine atom was carried out by using NaH as

In contrast, the same coupling reaction with DMTMM

base to transform the diethyl malonate diester into its corre- gave 54% yield. This was at odds with the result of coupling

sponding anion so that the adducts D4-mal and D5-mal of the same acid with a much larger amine, the 6Ј-amino-

could be obtained. Saponification of the diesters was per- lactose 7. The results of the two alternative approaches are

formed by using KOH and THF/water as the solvent, and reported in Table 2, which shows that the use of

successive acidification with HCl led to D4-diac and D5- DMTMM^[17]as the coupling reagent gives the best results,

diac. The final naturalised dyes NatD4 and NatD5, respec- both in terms of yields and reaction times.

tively, were obtained according to the procedure described

above, via NatD4-p and NatD5-p (Scheme 10).

Table 2. Results of the condensation of the dicarboxylic acid D3-

ac with the amine group of 7 using coupling agents.^[a]

Entry

Coupling reagent

Base

Reaction time [h] % Yield

Coupling Reactions

1

2

DMTMM^[17]

Ethyl chloro-

formate

NMM

Et₃N

16

30

92

66

The amidic bond between the dicarboxylic acid D3-diac

and the amine group of derivative 7 was formed by the use

of two coupling agents. Ethyl chloroformate is a common [a] Reactions were carried out in THF as solvent at room tempera-

ture.

coupling reagent used for the formation of amidic com-

pounds when they are derived from carboxylic acid and a

small molecule like 12, in this case affording the desired

product in 91% yield after two cycles of activation with oxy-1,3,5-triazine (CDMT; 13) and N-methylmorpholine

ethyl chloroformate. (NMM; 14) at room temperature (Scheme 11).

DMTMM (15) was prepared from 2-chloro-4,6-dimeth-

2754

www.eurjoc.org

Eur. J. Org. Chem. 2009, 2748–2764

Synthesis of Water-Soluble Large Naturalised Dyes

The results reported in Table 3 show that λ_maxdoes not

exhibit any significant shift after the double glycoconjug-

ation with the two glycide units. Also, molar extinction co-

efficient values can be considered almost constant, only

very small differences being detected.

Table 3. UV/Vis absorption spectra of the dyes D1–D5 and of their

glycoconjugated derivatives. Entry D2-x formula is represented be-

low.

Scheme 11. Preparation of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-

methylmorpholinium chloride (DMTMM) according to Kunish-

ima et al.^[17]

Dye

λ_max(MeOH) [nm]

log(ε_(max)/^–1cm^–1)

D1

415

416

502

503

414

415

456

457

482

483

500

501

503

4.3194

4.3048

4.3114

4.5328

4.6277

4.3364

4.3344

4.3374

4.8383

4.9304

4.8324

4.4356

4.4344

4.4329

4.3006

4.2863

4.2948

NatD1-p

NatD1

D2

These triazinylammonium reagents react with the car-

boxylic acid to form the “triazine active ester”^[18]in THF

as solvent in 2 h and then this “super-active ester” couples

easily with the amine group in high yield. In the other coup-

D2-x

D2-bz

NatD2-p

NatD2

ling process, the activation of the carboxylic acid using ethyl D3

NatD3-p

NatD3

D4

NatD4-p

NatD4

D5

NatD5-p

NatD5

chloroformate led to the formation of the carboxylic anhy-

dride, which has limited stability during the reaction, so

that it was necessary to activate the acid twice to obtain the

amidic compound in an acceptable yield. Similar results

were obtained in the cases of D4 and D5, for which the

yields obtained with DMTMM as the coupling reagent

were around 90%.

Thus, derivatization of the alcoholic or carboxylic func-

tions in dyes D3, D4 and D5 does not affect the UV/Vis

spectrum as these groups are far from the chromophore.

Very small changes are apparent in the spectra of com-

pound D1, but on the other hand, even comparing the phe-

nolic band with the corresponding band of anisole in prac-

tice shows no significant differences. The only electronic ab-

sorption spectrum that clearly changes is that of D2-Bz, in

which the aromatic NH₂group is changed and transformed

into the amide derivative. Here, as expected, hypso- and hy-

pochromic shifts are observed.

We also prepared compound D2-x, in which the phenolic

hydroxy group was treated with ethyl bromoacetate without

previous protection of the amino group. Compound D2-x

in fact displays the same colour as the starting D2 (Fig-

ure 4). But, as already stressed, without benzoylation of the

amino group, the synthesis of D2-eth was hampered.

UV/Vis Spectra Studies

UV/Vis absorption spectra of the newly generated natu-

ralised dyes are crucial because the modified dyes should

display the same colour as the starting materials if the chro-

mophore is not affected by the glycoconjugation process, as

in dyes D3, D4 and D5, whereas the phenolic hydroxy group

was used to attach the spacer in dyes D1 and D2. The UV/

Vis spectra of the starting red dye D4, the protected dye

NatD4-p and the deprotected dye NatD4 in MeOH are

shown in Figure 3.

Figure 4. Formula of D2-x.

Tinctorial Tests

Tinctorial tests were carried out on the naturalised dyes

NatD1, NatD4 and NatD5. NatD5 was compared with the

same dye protected with monosuccinyllactose. The dyeing

Figure 3. UV/Vis absorption spectra of the D4, NatD4-p and

Natd-4.

Eur. J. Org. Chem. 2009, 2748–2764

www.eurjoc.org

2755

J. Isaad, M. Rolla, R. Bianchini

FULL PAPER

Table 4. Dyeing conditions with naturalised dyes.

Fabric

Polyester

Cotton, step1

Cotton, step2

Acetate

Wool

Polyacrylic

Temperature [°C]

Dye concentration [%]

Time [min]

Acetic acid added [%]

Other

98

0.5

30

1

80

0.5

35

–

98

0.5

15

–

84

0.5

30

1

98

0.5

20

1

98

0.5

30

2

–

Na₂SO₄(10 g/L) Na₂CO₃(0.5 g/L)

–

(NH₄)₂SO₄(amount?)

–

conditions are reported in Table 4. Note that the dye per-

centages refer to the weight of the dyes in water, but as the

naturalisation almost doubles the molecular weight of the

dyes, a reliable comparison requires that the colour ob-

tained with an approximately 1% solution of the natural-

ised dyes should be compared with a 0.5% solution of the

corresponding starting dyes. The starting materials are in-

soluble in water and have a low affinity towards the fabrics.

Therefore, during the dyeing process with the starting dyes,

surface-active agents were added to disperse them in water

and also many mordents to increase their affinity towards

the fabrics. On the other hand, the original dyes become

soluble in cold water after naturalisation through glycocon-

jugation with lactose. The solubilities of these dyes are re-

ported in Table 5.

Table 5. Solubilities of the naturalised dyes.

Naturalised dyes

Solubility [g/L]^[a]

NatD1

NatD2

NatD3

NatD4

NatD5

71.86

67.22

83.47

84.11

82.65

Figure 5. a) Tinctorial tests on NatD1, NatD3 and NatD5 carried

out on wool (Wo, left), polyacrylic (PC), polyester (PL), Nylon

(NY), cotton (Co) and polyacetate (Ac, right). b) NatD5, disperse

red 1, NatD1, disperse orange 29 dyes used in the dyeing of fabric

in water at 95 °C for 30 min in 0.5 (Nat dyes) or 0.25% (disperse

dyes) solutions. The stripes are polyacetate, cotton, nylon, poly-

ester, polyacrylic and wool starting from the top. On the left, the

resulting water solution of 15 mL of water on 0.5 g of fabric dyed

with disperse red 1 (left) and NatD5 (right).

[a] The solubility was measured at room temperature.

Thus, these naturalised dyes are multipurpose, that is, our

second goal has been achieved even with two units of lac-

tose bonded, as shown in Figure 5. The multicomponent

fabric in fact shows that naturalised dyes are effective tion wets the fabric, and this process produces the results

towards all the materials, wool, acetate, acrylic, nylon, poly- shown in Figure 5 (b). Of course, a similar approach is of

ester and even cotton (Figure 5, a), and this is at variance no industrial use, but here it allows an effective comparison.

with dyes naturalised with a single lactose, with which cot- Looking at Figure 5 (b), and considering that the sequence

ton exhibited contradictory results. Moreover, dyeing is ef- of the strips from top to bottom is polyacetate, cotton,

fective at temperatures below 100 °C in a short time (30 min nylon, polyester, acrylic and wool, in both cases the disperse

as a maximum) and without the addition of dangerous sur- dyes, those in positions 2 and 4, appear to dye the polyacet-

face agents or mordents and even cotton dyed better than ate, mainly the nylon, and the polyester, but the dyeing

with single lactose glycoconjugation.

failed in the case of cotton, acrylic and wool, bearing in

In Figure 5 (b) two multicomponent fabrics dyed with mind that wool itself is a pale-brown colour. We can con-

NatD1 and NatD5 are compared with the same fabric dyed clude that the naturalised dyes are multipurpose, but this is

with the corresponding diperse dyes in water. The dyeing not the case for the disperse dyes. We then considered the

was carried out in the four cases by using a 0.5% solution quality of the dyeing. We weighed 0.5 g of each, NatD5 and

of naturalised dyes and 0.25% of the disperse dye solutions. disperse red, and then added 15 mL of water and we kept

This difference is necessary because half of the molecular the solutions at 95 °C for 30 min. The results are shown in

weight of the naturalised dyes is due to the glycidic moieties. the right-hand side of Figure 5 (b), the vial with the red

The dyeing procedure involved keeping the fabric in the dif- solution is from the disperse dye, the almost transparent

ferent dyes for 30 min at 95 °C. Before discussing the results one from NatD5. Thus, we can say again that the dyeing of

let us consider that the disperse dyes are not soluble in the naturalised materials is appropriate and the fastness is

water, except when the temperature of the water is raised. very good, whereas the disperse dye is lacquered onto the

At that point equilibrium is established as the dye in solu- surface, mainly on the nylon strip.

2756

www.eurjoc.org

Eur. J. Org. Chem. 2009, 2748–2764

Synthesis of Water-Soluble Large Naturalised Dyes

Dyeing and Fastness Conditions: The dyeing process was designed

to be as close as possible to the classic traditional method of dyeing

described by Cardon.^[20,21]This process was adapted to our dyeing

methodology with a process bath of eight dyeing beakers (250 mL

each) driven by a microprocessor time–temperature controller. The

dyeing bath was prepared by stirring dye material (1%) in deionised

water under magnetic stirring for 10 min. Later, the bath was co-

oled to room temperature (20 °C) to avoid felting, especially of the

wool.^[21]Then the fabrics and the dyeing bath were put together in

the dyeing beaker (bath ratio, 1 g of fabric/50 mL of dye solution).

The beakers were placed in the machine and the dyeing was carried

out under mechanical stirring. The fastness to washing and scrap-

ing, and to light, was tested according to the well-known standard

procedure.

Colour Fastness

Table 6 shows the wash and scraping, and light fastness

data on wool of the naturalised dyes according to inter-

national fastness methods, ISO 105-C06 and ISO 105-X12,

respectively. The fastness measurements definitively show

that the dyes are not lacquered onto the surface of the mate-

rial, but penetrate it and are efficiently bonded.

Table 6. Fastness tests for wool dyed with NatDs 1, 2, 3 and 5.

Dyes

Wash fastness

Light fastness

NatD1

NatD2

NatD3

NatD5

5

4

5

4/5

5

1-Bromopentoxy-4-({2Ј-methoxy-4Ј-[(4ЈЈ-nitrophenyl)azo]phenyl}-

phazo)enol (D1-eth). General Procedure A: A mixture of the D1

(1.0 g, 2.65 mmol), KOH (0.715 g, 7.96 mmol) and 18-crown-6

ether (0.01 equiv.) in THF (10 mL) was stirred at room temperature

for 1 h. Then 1,5-dibromopentane (1.09 mL, 5.31 mmol) was added

and the mixture was stirred under the same conditions for several

Conclusions

From the results reported above, we can conclude that

the double derivatisation of large-molecule dyes with lac- hours. TLC analysis (EtOAc/petroleum ether, 1:10) revealed the

complete disappearance of the starting material (R_f= 0.13) and the

formation of a major faster-moving product (R_f= 0.44). The crude

solution was neutralised with saturated NH₄Cl (15 mL) and ex-

tracted with DCM (3ϫ20 mL). The organic phase was dried with

Na₂SO₄, concentrated under reduced pressure and the resulting res-

idue was purified by flash chromatography (EtOAc/petroleum

ether, 1:10) to yield D1-eth (1.23 g, 67%). ¹H NMR (200 MHz,

CDCl₃): δ = 8.44–8.36 (m, 2 H, Ar-H), 8.18–7.91 (m, 4 H, Ar-H),

7.88–7.76 (m, 3 H, Ar-H), 7.02 (m 2 H, Ar-H), 3.63–3.40 (m, 7 H,

PhOCH₃, OCH₂, CH₂Br), 1.77 (m, 2 H, CH₂CH₂Br), 1.48 [m, 4

H, (CH₂)₂] ppm. ¹³C NMR (50 MHz, CDCl₃): δ = 159.61 (Ar-C),

156.85 (Ar-C), 155.22 (Ar-C), 153.86 (Ar-C), 148.48 (Ar-C), 148.07

(Ar-C), 143.98 (Ar-C), 125.06 (Ar-C), 124.44 (Ar-C), 123.26 (Ar-

C), 118.32 (Ar-C), 117.33 (Ar-C), 114.76 (Ar-C), 109.98 (Ar-C),

67.34 (OCH₂), 56.18 (PhOCH₃), 33.98 (CH₂Br), 31.34

(CH₂CH₂Br), 27.88 (OCH₂CH₂), 26.90 (CH₂CH₂CH₂) ppm. MS

(ESI): m/z = 526.10 [M + 1]⁺. C₂₄H₂₄BrN₅O₄(526.38): calcd. C

54.76, H 4.60; found C 54.71, H 4.55.

tose actually results in good solubility in water. This new

property of the novel materials allows milder and simpler

dyeing processes, avoiding the use of surface agents, mor-

dants and other polluting additives, because the dyeing is

efficient once the starting dyes have been glycoconjugated.

And with two units of lactose instead of one, the dyeing

process is even improved in some cases. Research towards

other forms of glycoconjugation is underway in our labora-

tory, with encouraging results.

Experimental Section

General Methods: TLC was carried out on silica gel pre-coated

plates (Merck; 60 Å F254) and spots located with (a) UV light (254

and 366 nm), (b) ninhydrin (solution in acetone), (c) fluorescamine,

(d) I₂or (e) a basic solution of permanganate [KMnO₄(3 g),

K₂CO₃(20 g) and NaOH (0.25 g) in water (300 mL)]. Flash column

chromatography (FCC) was carried out on Merck silica gel 60

(230–400 mesh) according to Still et al.^{[19] 1}H and ¹³C NMR spec-

tra were recorded at 200 MHz with Varian spectrometers in deuter-

iated solvents and are reported in parts per million (ppm) with the

solvent resonance used as the internal reference. Mass spectra were

recorded with a Thermo Fisher LCQfleet ion-trap instrument. (the

spectra reported were also using the ESI +c technique). Elemental

analysis was carried out with a Perkin–Elmer 240 C Elemental An-

alyzer. UV/Vis spectra were recorded with a Cary-4000 Varian

spectrophotometer. The commercial dyes D1 [disperse orange 29,

4-({2-methoxy-4-[(4-nitrophenyl)azo]phenyl}azo)phenol], D2 (dis-

perse red 60, 1-amino-4-hydroxy-2-phenoxyanthraquinone), D3

[disperse orange 25, 3-(ethyl{4-[(4-nitrophenyl)azo]phenyl}amino)-

propiononitrile], D4 [disperse red 13, 2-(ethyl{4-[(2-chloro-4-nitro-

phenyl)azo]phenyl}amino)ethanol] and D5 (disperse red 1, 2-(ethyl-

{4-[(4-nitrophenyl)azo]phenyl}amino)ethanol] were purified by

FCC with an appropriate eluent. Compounds 1, 8, 18, 19, N-meth-

ylmorpholine (NMM), 3,5-dimethoxy-1-chlorotriazine (CDMT),

ethyl chloroformate and diethyl malonate are commercially avail-

able (Sigma–Aldrich) and used as such. Literature methods were

used to prepare 2,3:5,6-bis-O-(1-methylethylidene)-4-O-[3,4-O-(1-

methylethylidene)-β--galactopyranosyl] dimethyl acetal (4),^[16]its

Synthesis of NatD1-eth-p: The product NatD1-eth-p was prepared

according to the general procedure A using the following quanti-

ties: D1-eth (1.00 g, 1.90 mmol), KOH (0.33 g, 5.71 mmol), lactose

derivative 4 (0.97 g, 1.9 mmol) in dry THF (25 mL). After work-

up the crude product was purified by FCC (EtOAc/petroleum ether,

2:1, R_f= 0.53) to afford NatD1-eth-p (1.48 g, 54%) as an orange

solid. ¹H NMR (200 MHz, CDCl₃): δ = 8.44 (m, 2 H, Ar-H), 8.16–

7.91 (m, 4 H, Ar-H), 7.88–7.76 (m, 3 H, Ar-H), 7.01 (m, 2 H, Ar-

H), 4.61 (t, J = 7.4 Hz, 1 H), 4.53 (m, 1 H), 4.36 (m, 1 H), 4.25

(m, 1 H), 4.15–3.90 (m, 9 H), 3.74–3.49 (m, 8 H), 3.44–3.43 (2 s, 6

H,

2 OCH₃), 1.91 (m, 2 H, OCH₂CH₂), 1.65 (m, 4 H,

CH₂CH₂CH₂), 1.55–1.30 [6 s, 18 H, 3 C(CH₃)₂] ppm. ¹³C NMR

(50 MHz, CDCl₃): δ = 159.75 (Ar-C), 157.02 (Ar-C), 155.67 (Ar-

C), 153.97 (Ar-C), 148.80 (Ar-C), 147.57 (Ar-C), 144.71 (Ar-C),

125.37 (Ar-C), 124.76 (Ar-C), 123.55 (Ar-C), 118.83 (Ar-C), 117.68

(Ar-C), 115.81 (Ar-C), 114.78 (Ar-C), 110.08, 109.87, 108.53

[C(CH₃)₂], 72.17–68.28 (2 OCH₂), 56.45 [C(OCH₃)₂], 53.88

(PhOCH₃), 29.60, 28.95, 28.91, 28.08, 27.28, 26.55, 26.27, 25.50,

22.51 ppm; see Table 7 for the glycidic moiety. UV/Vis: λ_max

=

416 nm; ε = 20133 ^–1cm^–1. MS (ESI): m/z = 954.43 [M + 1]⁺.

C₄₇H₆₃N₅O₁₆(954.04): calcd. C 59.17, H 6.66; found C 59.12, H

6.61.

6-O-[(4-methylphenyl)sulfonyl 5^[17]and 6-amino-6-deoxy-1,2:3,4- Synthesis of NatD1-eth. General Procedure B: A solution of NatD1-

di-O-isopropylidene--galactopyranoside (8).^[15a]

eth-p (1.00 g, 1.05 mmol) in 90% aqueous TFA (15 mL) was stirred

Eur. J. Org. Chem. 2009, 2748–2764

www.eurjoc.org

2757

J. Isaad, M. Rolla, R. Bianchini

FULL PAPER

Table 7. ¹³C NMR spectroscopic data for the glycide portion of the protected lactose derivatives.

Compound

Solvent

δ [ppm]

C-1Ј

C-2Ј

C-3Ј

C-4Ј

C-5Ј

C-6Ј

C-1

C-2

C-3

C-4

C-5

C-6

6

CDCl₃

Me₂SO

103.54 79.66

103.33 79.49

102.92 81.33

103.60 79.08

103.74 79.68

103.34 81.33

103.43 79.02

103.49 79.06

103.12 79.64

79.06

78.01

79.67

78.08

78.40

79.57

77.18

77.97

78.04

71.51

73.48

72.57

72.66

74.27

73.35

73.97

74.09

73.83

72.17

70.97

71.41

70.72

71.94

72.04

72.45

72.61

71.22

40.14

107.9

75.54

77.42

75.65

78.15

76.61

77.88

78.99

76.87

77.07

76.54

74.04

74.48

73.81

71.39

73.57

73.79

73.82

73.21

72.25

76.22

75.19

75.95

76.14

77.66

77.59

77.82

76.81

76.42

67.67

64.60

65.38

64.72

64.57

64.80

64.60

64.63

64.22

7

42.22 106.51 73.94

62.39 106.78 74.27

40.38 106.11 74.21

40.89 106.61 74.44

40.46 106.07 75.11

40.63 106.24 74.15

40.49 106.03 74.22

40.06 106.78 75.10

NatD1-ethp

NatD1-bP

NatD1-mP

NatD2-p

NatD3-p

NatD4-p

NatD5-p

Table 8. ¹³C NMR spectroscopic data (δ, ppm) for the glycide portion of deprotected lactose derivatives.

Compound

Solvent

δ [ppm]

C-1Ј

C-2Ј

C-3Ј

C-4Ј

C-5Ј

C-6Ј

C-1

C-2

C-3

C-4

C-5

C-6

β-Lactose^[a]

NatD1-eth-β

NatD1-m-β

NatD1-b-β

NatD2-β

D₂O

103.74 72.00

73.51

73.39

73.69

73.33

73.38

73.58

73.45

73.5

73.06

73.84

72.29

69.54

68.42

68.41

68.89

68.67

68.36

68.33

69.5

68.26

68.35

68.79

76.28

74.72

74.84

74.56

74.47

74.75

74.38

76.2

74.45

74.62

73.53

62.06

67.51

40.39

40.67

40.37

40.34

40.44

62.0

67.51

40.10

40.47

96.62

95.12

95.75

95.85

95.51

95.73

95.86

95.35

92.74

95.06

95.72

95.67

95.47

74.83

74.21

74.55

73.35

73.15

74.52

74.16

72.23

72.76

72.36

72.53

72.08

75.32

75.12

75.07

75.17

74.92

74.60

75.22

75.38

72.4

72.16

72.27

71.98

79.28

80.08

80.18

80.48

80.62

80.51

80.86

79.34

81.22

80.79

80.71

81.44

75.66

75.33

75.22

75.51

75.52

75.36

75.71

71.03

71.39

71.82

71.66

61.1

acetone 102.31 72.62

acetone 102.88 72.73

acetone 102.27 72.73

D₂O

60.82

60.64

60.63

60.90

60.34

60.43

60.25

61.17

60.79

60.57

60.55

60.43

102.64 72.04

103.25 72.64

102.74 72.29

102.74 72.80

103.62 72.04

NatD3-β

NatD4-β

NatD5-β

α-Lactose^[a]

NatD1-eth-α

NatD1-m-α

NatD1-b-α

NatD2-α

acetone 102.31 72.49

acetone 102.68 72.53

acetone 102.84 72.44

D₂O

102.48 72.00

[a] Taken from ref.^[22]

at room temperature for 3 h. TLC (EtOAc/petroleum ether, 2:1)

indicated that the starting material (R_f= 0.44) had completely re-

acted with the formation of the deprotected compound NatD1-eth

(R_f= 0.1). The violet solution was repeatedly co-evaporated with

toluene (5ϫ25 mL) at reduced pressure to give the final product

NatD1-eth (0.78 g, 94%) as a red powder consisting of a mixture

of α- and β-pyranosic anomers in a ratio of 50:50, calculated on

water (3ϫ20 mL). The organic phase was dried with Na₂SO₄, con-

centrated under reduced pressure and the resulting residue was

purified by flash chromatography (EtOAc/petroleum ether, 3:10, R_f

= 0.59) to yield D1Ј (1.15 g, 82%) as an orange solid. ¹H NMR

(200 MHz, CDCl₃): δ = 8.41–8.33 (m, 2 H, Ar-H), 8.09–7.94 (m, 4

H, Ar-H), 7.81–7.67 (m, 3 H, Ar-H), 7.11 (m, 2 H, Ar-H), 5.31 (s,

1 H, CH), 4.35 (q, J = 7.00 Hz, 4 H, 2CH₂CH₃), 4.12 (s, 3 H,

PhOCH₃), 1.32 (t, J = 7.00 Hz, 6 H, 2 CH₃) ppm. ¹³C NMR

(CDCl₃): δ = 164.88 (CO), 159.22 (Ar-C), 157.13 (Ar-C), 155.50

1

the basis of the relative C-1 signal intensities. H NMR(200 MHz,

acetone): δ = 8.44 (m, 2 H, Ar-H, α- and β-pyranose), 8.23–7.89

(m, 4 H, Ar-H, α and β-pyranose), 7.79–7.64 (m, 3 H, Ar-H, α and (Ar-C), 154.13 (Ar-C), 148.77 (Ar-C), 148.65 (Ar-C), 144.35 (Ar-

β-pyranose), 7.11 (m, 2 H, Ar-H, α- and β-pyranose), 5.11–4.51 C), 125.18 (Ar-C), 124.69 (Ar-C), 123.52 (Ar-C), 118.50 (Ar-C),

(m, 2 H, α-β pyranose), 4.32–4.19 (m, 4 H), 3.87–3.79 (m, 6 H), 117.65 (Ar-C), 115.65 (Ar-C), 114.96 (Ar-C), 105.54 (CH), 62.76

3.71–3.41 (m, 9 H), 1.87 (m, 2 H, OCH₂CH₂, α- and β-pyranose), (CH₂CH₃), 56.59 (PhOCH₃), 14.22 (2 CH₃) ppm. MS (ESI): m/z =

1.64 (m, 4 H, CH₂CH₂CH₂, α- and β-pyranose) ppm.¹³C NMR 536.17 [M + 1]⁺. C₂₆H₂₅N₅O₈(535.51): calcd. C 58.31, H 4.71;

(50 MHz, CDCl₃): δ = 159.85 (Ar-C), 157.08 (Ar-C), 155.48 (Ar- found C 58.24, H 4.65.

C), 154.17 (Ar-C), 148.76 (Ar-C), 148.23 (Ar-C), 144.20 (Ar-C),

125.33 (Ar-C), 124.51 (Ar-C), 123.43 (Ar-C), 118.60 (Ar-C), 117.62

(Ar-C), 115.17 (Ar-C), 114.28 (Ar-C), 109.50 (Ar-C), 70.99–68.55

Synthesis of D1ЈЈ. General Procedure C: A 1  solution of KOH

(10 mL) was added to a solution of D1Ј (1.00 g, 1.87 mmol) in diox-

ane (10 mL) and the resulting mixture was stirred at room tempera-

ture for 2 h. TLC (ethyl acetate) indicated the disappearance of the

(2 OCH₂), 56.58 (PhOCH₃), 30.30, 29.44, 28.27 ppm; see Table 8

for the glycidic moiety. UV/Vis: λ_max= 416 nm; ε = 20157 ^–1cm^–1.

starting product (R_f= 0.81) and the formation of one major spot

MS (ESI): m/z = 788.33 [M + 1]⁺. C₃₆H₄₅N₅O₁₅(787.78): calcd. C

(R_f= 0.1). The solution was diluted with water (25 mL) and ex-

tracted with chloroform (3ϫ20 mL). The aqueous solution was

54.89, H 5.76; found C 54.77, H 5.69.

Diethyl 2-[4-({2Ј-methoxy-4Ј-[(4ЈЈ-nitrophenyl)azo]phenyl}azo)phen-

oxy]malonate (D1Ј): A mixture of 60% NaH (0.11 g, 2.65 mmol) in

acidified with an aqueous solution of 1  HCl to pH = 2 and ex-

tracted with chloroform (30 mL). The organic layer was dried with

THF (2 mL) was added slowly at 0 °C to a solution of D1 (1.0 g, Na₂SO₄and filtered. The solvent was removed under reduced pres-

2.65 mmol) in THF (10 mL) and the resulting mixture was stirred

at room temperature for 30 min. Diethyl chloromalonate (1;

1.30 mL, 2.65 mmol) was added and the mixture was stirred at

room temperature for several hours. TLC analysis (EtOAc/petro-

leum ether, 3:10) revealed the disappearance of the starting material

(R_f= 0.21) and the formation of a major product (R_f= 0.59). The

crude solution was diluted with DCM (15 mL) and washed with

sure to afford D1ЈЈ (0.87 g, 96%) as a black solid. ¹H NMR

(200 MHz, [D₆]acetone): δ = 8.51–8.43 (m, 2 H, Ar-H), 8.22–7.97

(m, 4 H, Ar-H), 7.82–7.74 (m, 3 H, Ar-H), 7.19–7.11 (m, 2 H, Ar-

H), 4.13 (s, 1 H, CH), 3.74 (s, 3 H, PhOCH₃) ppm. ¹³C NMR

(50 MHz, CDCl₃): δ = 163.57 (CO), 159.69 (Ar-C), 157.19 (Ar-C),

155.01 (Ar-C), 154.96 (Ar-C), 147.87 (Ar-C), 147.83 (Ar-C), 144.40

(Ar-C), 124.91 (Ar-C), 124.81 (Ar-C), 123.56 (Ar-C), 117.44 (Ar-

2758

www.eurjoc.org

Eur. J. Org. Chem. 2009, 2748–2764

Synthesis of Water-Soluble Large Naturalised Dyes

C), 117.39 (Ar-C), 115.64 (Ar-C), 114.56 (Ar-C), 105.02 (CH), B using the following quantities: NatD1-mp (1.8 g, 1.86 mmol) in

56.02 (PhOCH₃) ppm. MS (ESI): m/z

=

480.21 [M

+

1]⁺.

TFA (15 mL) to afford NatD1-m (1.44 g, 98%) as an orange pow-

C₂₂H₁₇ClN₅O₈(514.86): calcd. C 55.12, H 3.57; found C 55.01, H der as a mixture of α- and β-pyranosic anomers in a ratio of 49:51

3.44.

calculated on the basis of the relative C-1 signal intensities.¹H

NMR (200 MHz, Acetone). δ = 8.43 (m, 2 H, Ar-H, both ano-

mers), 8.28–7.88 (m, 4 H, Ar-H, both anomers), 7.77–7.61 (m, 3

H, Ar-H, both anomers), 7.19 (m, 2 H, Ar-H, both anomers), 5.10,

4.55 (m, 2 H, both anomers), 4.31–4.16 (m, 4 H, both anomers),

3.88–3.79 (m, 6 H, both anomers), 3.77–3.52 (m, 4 H, PhOCH₃,

CH, both anomers), 3.44–3.41 (m, 2 H, both anomers) ppm. ¹³C

NMR (50 MHz, acetone): δ = 164.88 (CO), 159.22 (Ar-C), 157.13

(Ar-C), 155.50 (Ar-C), 154.13 (Ar-C), 148.77 (Ar-C), 147.65 (Ar-

C), 144.35 (Ar-C), 125.18 (Ar-C), 124.69 (Ar-C), 123.51 (Ar-C),

118.50 (Ar-C), 117.65 (Ar-C), 115.64 (Ar-C), 114.96 (Ar-C), 105.55

(CH), 56.58 (PhOCH₃) ppm; see Table 8 for the glycidic moiety.

UV/Vis: λ_max= 416 nm; ε = 20111 ^–1cm^–1. MS (ESI): m/z =

803.71 [M + 1]⁺. C₃₄H₃₈N₆O₁₇(802.70): calcd. C 50.87, H 4.77;

found C 50.74, H 4.71.

Synthesis of NatD1-mp. General Procedure D: NMM (0.23 mL,

2.08 mmol) was added to a solution of D1ЈЈ (1.00 g, 2.08 mmol) in

THF (15 mL) and the mixture was stirred at room temperature for

5 min. The resulting solution was cooled to 0 °C, DMTMM

(0.58 g, 2.08 mmol) was added and the mixture was stirred at room

temperature for 20 h. After this time TLC (EtOAc/petroleum ether,

5:1) indicated the formation of the activated intermediate (R_f=

0.64) and the disappearance of the starting acid (R_f= 0.1). Pro-

tected amino-lactose 7 (1.06 g, 2.08 mmol) was added and the reac-

tion mixture was stirred at room temperature for 16 h. TLC

(EtOAc/petroleum ether, 5:1) showed the formation of one major

spot at (R_f= 0.38). The reaction mixture was evaporated to dryness

under reduced pressure and the residue was dissolved in chloroform

(20 mL) and washed with a solution of 5% HCl (20 mL) and water

(3ϫ20 mL). The organic solution was dried with Na₂SO₄and fil-

tered. The filtrate was concentrated under reduced pressure and the

residue (obtained as a red solid) was purified by flash chromatog-

raphy (EtOAc/petroleum ether, 5:2, R_f= 0.38) to afford NatD1-mp

Synthesis of 2-[4-({2Ј-Methoxy-4Ј-[(4ЈЈ-nitrophenyl)azo]phenyl}azo)-

phphenoxy]malonic Di-6Ј-aminolactose Diamide (NatD1-b): The

product NatD1-b was prepared according to the general procedure

B using the following quantities: NatD1-bp (1.50 g, 1.03 mmol) in

TFA (15 mL) to afford NatD1-b(1.13 g, 98%) as an orange powder

as a mixture of α- and β-pyranosic anomers in a ratio of 40:60

calculated on the basis of the relative C-1 signal intensities. ¹H

NMR (200 MHz, D₂O): δ = 8.35 (m, 2 H, Ar-H, both anomers),

8.18–7.89 (m, 4 H, Ar-H, both anomers), 7.81–7.64 (m, 3 H, Ar-

H, both anomers), 7.74 (m, 2 H, Ar-H, both anomers), 5.08, 4.57

(3 m, 4 H, both anomers), 4.24–4.17 (m, 8 H, both anomers), 3.91–

3.81 (m, 12 H, both anomers), 3.75–3.49 (m, 4 H, PhOCH₃, CH,

both anomers), 3.43–3.40 (m, 4 H, both anomers) ppm. ¹³C NMR

(50 MHz, D₂O): δ = 164.77 (2 CO, both anomers), 159.31 (Ar-C,

both anomers), 157.22 (Ar-C, both anomers), 155.59 (Ar-C, both

anomers), 154.15 (Ar-C, both anomers), 148.88 (Ar-C, both ano-

mers), 148.65 (Ar-C, both anomers), 144.43 (Ar-C, both anomers),

125.19 (Ar-C, both anomers), 124.65 (Ar-C, both anomers), 123.91

(Ar-C, both anomers), 118.68 (Ar-C, both anomers), 117.60 (Ar-C,

both anomers), 115.55 (Ar-C, both anomers), 114.66 (Ar-C, both

anomers), 105.64 (CH, both anomers), 56.58 (PhOCH₃, both ano-

1

(1.85 g, 77%) as an orange solid. H NMR (200 MHz, CDCl₃): δ

= 8.43 (m, 2 H, Ar-H), 8.12–7.89 (m, 4 H, Ar-H), 7.79–7.63 (m, 3

H, Ar-H), 7.03 (m, 2 H, Ar-H), 4.72 (d, J_HH= 7.1 Hz, 1 H), 4.53

(dd, J_HH= 6.3, J_HH= 7.0 Hz, 1 H), 4.36 (d, 1 H), 4.25 (m, 2 H),

4.15–3.97 (m, 6 H), 3.74–3.49 (m, 7 H), 3.44–3.43 (2 s, 6 H,

2 OCH₃), 1.48–1.29 [various overlapping signals, 18 H, 3 C-

(CH₃)₂] ppm. ¹³C NMR (50 MHz, CDCl₃): δ = 165.78 (CO),

158.49 (Ar-C), 155.66 (Ar-C), 154.61 (Ar-C), 154.31 (Ar-C), 148.70

(Ar-C), 148.43 (Ar-C), 144.53 (Ar-C), 125.57 (Ar-C), 124.10 (Ar-

C), 123.61 (Ar-C), 118.86 (Ar-C), 117.46 (Ar-C), 115.27 (Ar-C),

110.52 (Ar-C), 110.37, 109.55, 108.08 [C(CH₃)₂], 105.47 (CH),

56.32 [C(OCH₃)₂], 54.45 (PhOCH₃), 28.80, 27.67, 26.36, 25.96,

25.40, 24.79 [C(CH₃)₂] ppm; see Table 7 for the glycidic moiety.

UV/Vis: λ_max= 416 nm; ε = 20209 ^–1cm^–1. MS (ESI): m/z =

969.44 [M + 1]⁺. C₄₅H₅₆N₆O₁₈(968.97): calcd. C 55.78, H 5.83;

found C 55.67, H 5.71.

Synthesis of NatD1-bp: The product NatD1-bp was prepared ac-

cording to the general procedure D using the following quantities:

D1ЈЈ(0.80 g, 1.67 mmol), NMM (0.55 mL, 5.01 mmol), DMTMM

(1.38 g, 5.01 mmol), amino-lactose derivative 7 (1.70 g, 3.34 mmol)

in THF (20 mL). The crude material was purified by FCC (EtOAc/

petroleum ether, 10:3, R_f= 0.39) to afford NatD1-bp (2.24 g, 92%)

as an orange solid. ¹H NMR (200 MHz, CDCl₃): δ = 8.38–8.27

(m, 2 H, Ar-H), 8.12–7.89 (m, 4 H, Ar-H), 7.75–7.64 (m, 3 H, Ar-

H), 7.13 (m, 2 H, Ar-H), 4.61–4.59 (m, 2 H), 4.53 (m, 2 H), 4.36

(m, 2 H), 4.25 (m, 3 H), 4.15–3.90 (m, 12 H), 3.74–3.49 (m, 11 H),

3.44–3.43 (2 s, 12 H, 4 OCH₃), 1.60–1.20 (various overlapping sig-

nals, 36 H) ppm. ¹³C NMR (50 MHz, CDCl₃): 167.88 (2 CO),

159.86 (Ar-C), 157.08 (Ar-C), 155.47 (Ar-C), 154.10 (Ar-C), 148.75

(Ar-C), 148.35 (Ar-C), 144.28 (Ar-C), 125.31 (Ar-C), 124.68 (Ar-

C), 123.51 (Ar-C), 118.49 (Ar-C), 117.62 (Ar-C), 115.07 (Ar-C),

110.25 (Ar-C), 110.14, 108.28, 106.20 [C(CH₃)₂], 105.53 (CH),

56.58 [C(OCH₃)₂], 54.89 (PhOCH₃), 28.27, 27.32, 26.62, 26.44,

25.87, 24.61 [C(CH₃)₂] ppm; see Table 7 for the glycidic moiety.

UV/Vis: λ_max= 416 nm; ε = 20174 ^–1cm^–1. MS (ESI): m/z =

1458.77 [M + 1]⁺. C₆₈H₉₅N₇O₂₈(1458.53): calcd. C 56.00, H 6.57;

found C 55.97, H 6.54.

mers) ppm; see Table 8 for the glycidic moiety. UV/Vis: λ_max

=

416 nm; ε = 20183 ^–1cm^–1. MS (ESI): m/z = 1126.01 [M + 1]⁺.

C₄₆H₅₉N₇O₂₆(1126.00): calcd. C 49.07, H 5.28; found C 48.97, H

5.19.

Synthesis of NatD1mp: The product NatD1mp was prepared ac-

cording to the general procedure D using the following quantities:

NatD1-mp (0.50 g, 0.51 mmol), NMM (0.08 mL. 0.77 mmol),

DMTMM (0.23 g, 0.77 mmol) and galactose derivative 8 (0.26 g,

0.51 mmol) in THF (20 mL). The crude adduct was purified by

FCC (EtOAc/petroleum ether, 2:1, R_f= 0.49) to afford NatD1mp

1

(0.47 g, 67%) as an orange solid. H NMR (200 MHz, CDCl₃): δ

= 8.43 (m, 2 H, Ar-H), 8.19–7.99 (m, 4 H, Ar-H), 7.73–7.62 (m, 3

H, Ar-H), 7.22 (m, 2 H, Ar-H), 5.52 (d, J_HH= 5.00 Hz, 1 H), 4.68–

4.52 (m, 3 H), 4.38–4.36 (m, 2 H), 4.27–4.25 (m, 3 H), 4.17–3.91

(m, 7 H), 3.76–3.55 (m, 9 H), 3.41–3.40 (2 s, 6 H, 2 OCH₃), 1.51–

1.21 [various singlets, 30 H, 5 C(CH₃)₂] ppm. ¹³C NMR (50 MHz,

CDCl₃): δ = 169.05 (2 CO), 159.77 (Ar-C), 157.54 (Ar-C), 155.11

(Ar-C), 154.50 (Ar-C), 148.85 (Ar-C), 148.14 (Ar-C), 144.31 (Ar-

C), 125.25 (Ar-C), 124.68 (Ar-C), 123.55 (Ar-C), 118.33 (Ar-C),

117.41 (Ar-C), 115.17 (Ar-C), 110.47, 110.24, 109.28, 108.84,

108.57 [5 C(CH₃)₂], 105.12 (C-1), 104.97 (CH), 100.11 (C-1Ј), 96.61

(C-1ЈЈ), 79.08, 77.27, 77.08 (C-3, C-5, C-3Ј), 75.61 (C-2), 76.45,

73.54, 73.21 (C-4, C-4Ј), 72.39 (C-2Ј), 70.88, 70.42 (C-2ЈЈ, C-4ЈЈ),

70.11 (C-3ЈЈ, C-5Ј), 67.77 (C-5ЈЈ), 64.72 (C-6), 40.77, 40.38 (C-6Ј,

Synthesis of 2-[4-({2Ј-Methoxy-4Ј-[(4ЈЈ-nitrophenyl)azo]phenyl}azo)-

phphenoxy]malonic 6Ј-Amino-lactose Monoamide (NatD1-m): The

product NatD1-m was prepared according to the general procedure

Eur. J. Org. Chem. 2009, 2748–2764

www.eurjoc.org

2759

J. Isaad, M. Rolla, R. Bianchini

FULL PAPER

C-6ЈЈ), 55.14 (PhOCH₃), 54.67 (2 OCH₃), 28.54, 28.27, 27.68,

27.32, 26.62, 26.44, 25.87, 25.35, 24.61, 24.51 [C(CH₃)₂] ppm. UV/

Vis: λ_max= 416 nm; ε = 20189 ^–1cm^–1. MS (ESI): m/z = 1210.53

[M + 1]⁺. C₅₇H₇₅N₇O₂₂(1210.25): calcd. C 56.57, H 6.25; found C

56.51, H 6.18.

mixture was stirred at room temperature for several hours. TLC

analysis (EtOAc/petroleum ether, 3:2) revealed the complete disap-

pearance of the starting material (R_f= 0.23) and the formation of

a major faster-moving product (R_f= 0.54). The pyridine was re-

moved under reduced pressure and the crude product was washed

with a 10 % HCl solution (20 mL) and extracted with DCM

(3ϫ20 mL). The organic phase was dried with Na₂SO₄, concen-

trated under reduced pressure and the resulting residue was puri-

fied by flash chromatography (EtOAc/petroleum ether, 3:2) to yield

Synthesis of 2-[4-({2Ј-Methoxy-4Ј-[(4ЈЈ-nitrophenyl)azo]phenyl}azo)-

phphenoxy]malonic 6Ј-Amino-lactose 6Ј-Aminogalactose Diamide

(NatD1mx): The product NatD1mx was prepared according to the

general procedure B using the following quantities: NatD1mp

(0.3 g, 0.24 mmol) in TFA (7 mL) to afford NatD1mx (0.23 g, 95%)

as an orange powder as a complex mixture of anomeric forms of

either the lactose or galactose moiety. Selected ¹H NMR

(200 MHz, D₂O): δ = 8.39 (m, 2 H, Ar-H), 8.21–7.89 (m, 4 H, Ar-

H), 7.71–7.52 (m, 3 H, Ar-H), 7.19 (m, 2 H, Ar-H), 5.11–4.68 (m,

4 H), 4.31–4.21 (m, 6 H), 4.09–3.61 (m, 8 H), 3.76–3.40 (m, 7 H,

both anomers) ppm. ¹³C NMR (50 MHz, D₂O): δ = 163.55–163.11

(2 CO, both anomers), 159.23 (Ar-C, both anomers), 157.05 (Ar-C,

both anomers), 155.12 (Ar-C, both anomers), 154.54 (Ar-C, both

anomers), 148.44 (Ar-C, both anomers), 147.17 (Ar-C, both ano-

mers), 144.11 (Ar-C, both anomers), 125.10 (Ar-C, both anomers),

124.35 (Ar-C, both anomers), 123.74 (Ar-C, both anomers), 117.57

(Ar-C, both anomers), 117.78 (Ar-C, both anomers), 114.00 (Ar-

C, both anomers), 114.41 (Ar-C, both anomers), 104.42 (CH, both

anomers), 102.50, 102.25 (C-1Ј, α- and β-pyranose), 101.10 (C-1ЈЈ,

β-furanose), 97.44 (C-1ЈЈ, β-pyranose), 96.74 (C-1, β-pyranose),

92.88 (C-1ЈЈ, α-pyranose), 92.10 (C-1, α-pyranose), 82.75 (C-4ЈЈ, β-

furanose), 81.54 (C-2ЈЈ, β-furanose), 80.88 (C-4, α- and β-pyra-

1

D2-Bz (1.15 g, 88%). H NMR (200 MHz, CDCl₃): δ = 8.35–8.22

(m, 2 H, Ar-H), 7.8–7.7 (m, 2 H, Ar-H), 7.5–7.0 (m, 8 H, Ar-H),

6.78–6.75 (m, 2 H, Ar-H), 6.34 (m, 1 H, Ar-H) ppm. ¹³C NMR

(50 MHz, CDCl₃): δ = 186.23–185.37 (2 CO), 166.47 (NHCO),

160.85, 154.08, 134.28, 134.24, 133.72, 132.93, 132.20, 130.14,

129.50, 129.30, 128.69, 128.41, 127.98, 127.26, 126.58, 125.66,

121.07, 110.43, 110.29 (Ar-C) ppm. MS (ESI): m/z = 436.21 [M +

1]⁺. C₂₇H₁₇NO₅(435.44): calcd. C 74.48, H 3.94; found C 74.38,

H 3.87.

N-[4-(5Ј-Bromopentoxy)-9,10-dioxo-2-phenoxyanthracen-1-yl]benz-

phamide (D2-Eth): K₂CO₃(1.25 g, 9.19 mmol) was added to a solu-

tion of disperse dye D2-Bz (1.0 g, 2.29 mmol) in acetone (25 mL)

and the resulting mixture was stirred at room temperature for 1.5 h.

Then 1,5-dibromopentane (0.94 mL, 6.88 mmol) and a catalytic

quantity of 18-crown-6 were added and the resulting solution was

heated at reflux for 20 h. At the end of the reaction, the resulting

solution was filtered, diluted with water (40 mL) and the aqueous

solution was extracted with chloroform (4ϫ30 mL). Then the or-

ganic phase was dried with Na₂SO₄and filtered. The filtrate was

concentrated under reduced pressure and the residue (obtained as

a red solid) was purified by flash chromatography (ethyl acetate/

petroleum ether, 1:2, R_f= 0.59) to afford D2-Eth (0.99 g, 74%) as

nose), 55.77 (PhOCH₃, both anomers) ppm. UV/Vis: λ_max

=

416 nm; ε = 20287 ^–1cm^–1. MS (ESI): m/z = 964.88 [M + 1]⁺.

C₄₀H₄₉N₇O₂₁(963.86): calcd. C 49.84, H 5.12; found C 49.77, H

5.18.

1

a yellow solid. H NMR (200 MHz, CDCl₃): δ = 8.35–8.22 (m, 2

Synthesis of 2,3:5,6-Bis-O-(1-methylethylidene)-4-O-[3,4-O-(1-meth-

H, Ar-H), 7.8–7.7 (m, 2 H, Ar-H), 7.5–7.0 (m, 8 H, Ar-H), 6.78–

6.75 (m, 2 H, Ar-H), 6.34 (m, 1 H, Ar-H), 3.45 (m, 4 H, OCH₂,

CH₂Br), 1.94–1.85 (m, 2 H, CH₂CH₂Br), 1.84, 1.42 (2ϫCH₂) ppm.

¹³C NMR (50 MHz, CDCl₃): δ = 187.14–181.88 (2ϫCO), 164.06

(NHCO), 162.27, 153.00, 136.85, 134.65, 134.07, 132.19, 130.43,

129.62, 127.57, 127.52, 127.23, 126.38, 126.23, 120.75, 111.47,

108.764, 108.68 (Ar-C), 68.24 (OCH₂), 33.86 (CH₂Br), 32.69

(CH₂CH₂Br), 27.07 (OCH₂CH₂), 26.10 (CH₂CH₂CH₂) ppm. MS

(ESI): m/z = 584.13 [M + 1]⁺. C₃₂H₂₆BrNO₅(584.47): calcd. C

65.76, H 4.48; found C 65.69, H 4.47

phylethylidene)]-6-O-[(azido)-β-D-galactopyranosyl]-aldehydo-D-glu-

cose Dimethyl Acetal (6): The derivative 6 was prepared from the

derivative 5 (1 mol) following the procedure reported in the litera-

ture^[15b]using NaN₃(1.5 mol) in DMSO (20 mL). The crude prod-

uct was purified by FCC (AcOH/petroleum ether, 2:1, R_f= 0.54)

to afford 6 in 81% yield. ¹H NMR (200 MHz, CDCl₃): δ = 4.60

(d, J = 7.9 Hz, 1 H), 4.53 (dd, J = 6.2, J = 7.8 Hz, 1 H), 4.28 (m,

1 H), 4.19 (m, 1 H), 4.17–3.96 (m, 6 H), 3.77–3.37 (m, 10 H), 1.40,

1.28, 1.20 (3 s, 18 H) ppm. ¹³C NMR (50 MHz, CDCl₃): δ = 109.78,

109.15, 108.94 [C(CH₃)₂], 56.32 [C(OCH₃)₂], 28.77, 27.33, 26.24,

26.34, 25.24, 24.57 [C(CH₃)₂] ppm; see Table 7 for the glycidic moi-

ety. MS (ESI): m/z = 534.59 [M + 1]⁺. C₂₃H₃₉N₃O₁₁: calcd. C 51.77,

H 7.37; found C 51.69, H 7.31.

Diethyl 2-[5-(4-Benzoylamino-9,10-dioxo-3-phenoxyanthracen-1-yl-

phoxy)pentyl]malonate (D2-mal). General Procedure E: A mixture

of 60% NaH (0.07 g, 1.71 mmol) in THF (2 mL) was added slowly

at 0 °C to a solution of D2-Eth (1.00 g, 1.71 mmol) in THF (10 mL)

and the resulting mixture was stirred at room temperature for

30 min. Diethyl malonate (0.28 mL, 1.71 mmol) was added and the

mixture was stirred at reflux for 20 h. TLC analysis (EtOAc/petro-

leum ether, 2:5) revealed the disappearance of the starting material

(R_f= 0.31) and the formation of a major product (R_f= 0.63). The

crude solution was diluted with chloroform (15 mL) and washed

with water (3ϫ20 mL). The organic phase was dried with Na₂SO₄,

concentrated under reduced pressure and the resulting residue was

purified by flash chromatography (EtOAc/petroleum ether, 2:5, R_f

Synthesis of 2,3:5,6-Bis-O-(1-methylethylidene)-4-O-[3,4-O-(1-meth-

phylethylidene)]-6-O-[(amino)-β-D-galactopyranosyl]-aldehydo-D-glu-

cose Dimethyl Acetal (7): The derivative 7 was prepared from the

derivative 6 following the procedure reported in the literature^[15b]

using 10% Pd in MeOH (10 mL) The crude reaction product was

purified by precipitation from diethyl ether to afford 7 in 96%

1

yield. H NMR (200 MHz, CDCl₃): δ = 4.55 (d, J = 8.0 Hz, 1 H),

4.50 (dd, J = 6.2, J = 7.9 Hz, 1 H), 4.29 (m, 1 H), 4.19 (m, 1 H),

4.17–3.95 (m, 6 H), 3.77–3.38 (m, 10 H), 1.41–1.20 (3 s, 18 H) ppm.

¹³C NMR (50 MHz, CDCl₃): δ = 110.10, 109.59, 108.16

[C(CH₃)₂], 57.37 [C(OCH₃)₂], 28.16, 27.10, 26.43, 26.30, 25.86,

24.26 [Cph(CH₃)₂] ppm; see Table 7 for the glycidic moiety. MS

(ESI): m/z = 508.39 [M + 1]⁺. C₂₃H₄₁NO₁₁(507.58): calcd. C 54.45,

H 8.15; found C 54.39, H 8.04.

1

= 0.63) to yield D2-Mal (1.13 g, 88%) as a red crystal. H NMR

(200 MHz, CDCl₃): this spectrum is identical to that of D2-eth, but

has some more signals due to the presence of the malonic moiety:

δ = 4.11 (q, J = 7.20 Hz, 4 H, 2CH₂CH₃), 3.75 (m, 1 H, CH), 3.31

(m, 2 H, OCH₂), 1.97–1.86 (m, 4 H, OCH₂CH₂, CH₂CH), 1.41–

N-(4-Hydroxy-9,10-dioxo-2-phenoxyanthracen-1-yl)benzamide (D2-

Bz): A mixture of D2 (1.0 g, 3.02 mmol) in pyridine (10 mL) was

added with benzoyl chloride (0.35 mL, 3.02 mmol) at 0 °C and the

1.34 (m, 4 H, 2ϫCH₂), 1.24 (t, J = 7.20 Hz, 6 H, 2 CH₃) ppm. ¹³

C

NMR (50 MHz, CDCl₃): δ = 187.15, 181.85 (2 CO), 170.55, 169.24,

164.06 (NHCO), 162.35, 153.00, 136.98, 134.60, 134.11, 132.01,

2760

www.eurjoc.org

Eur. J. Org. Chem. 2009, 2748–2764

Synthesis of Water-Soluble Large Naturalised Dyes

132.20, 130.39, 129.54, 129.22, 128.29, 127.59, 127.48, 127.23, (OCH₂CH₂), 29.66 (CH₂CH), 28.23 (CH₂CH₂CH), 27.08

126.36, 126.17, 120.82, 111.45, 108.65, 108.38 (Ar-C), 68.00

(CH₂CH₂CH₂) ppm; see Table 8 for the glycidic moiety. UV/Vis:

(OCH₂), 61.29 (CH₂CH₃), 50.23 (CH), 28.83 (OCH₂CH₂), 27.63 λ_max= 415 nm; ε = 21747 ^–1cm^–1. MS (ESI): m/z = 1254.43 [M +

(CH₂CH), 27.37 (CH₂CH₂CH), 27.16 (CH₂CH₂CH₂) ppm. MS 1]⁺. C₅₉H₇₁N₃O₂₇(1254.21): calcd. C 56.50, H 5.71; found C 56.42,

(ESI): m/z = 664.33 [M + 1]⁺. C₃₉H₃₇NO₉(663.72): calcd. C 70.58,

H 5.65.

H 5.62; found C 70.44, H 5.57.

tert-Butyl 2-Chloroethylcarbamate (10): A solution of NaHCO₃

(8.77 g, 104.34 mol) in water (15 mL) was added dropwise to a mix-

ture of the 2-chloroethylamine hydrochloride (9) (2.49 g,

11.39 mmol), di-tert-butyl dicarbonate (9.68 g, 20.86 mmol) and

1,4-dioxane (10 mL) at 0 °C and the mixture was stirred at 0 °C for

a further 18 h. After this time, the mixture was diluted with water

(25 mL) and then extracted with DCM (3ϫ25 mL). The combined

organic phases were dried, filtered and concentrated to leave a

crude brown oil. This oil was purified by column chromatography

(EtOAc/petroleum ether, 3:1, R_f= 0.68) to give 10 (1.98 g; 97%) as

a colourless oil. ¹H NMR (200 MHz, CDCl₃): δ = 3.56 (t, J =

4.8 Hz, 2 H, CH₂Cl), 3.42 (t, J = 4.8 Hz, 2 H, CH₂CH₂Cl), 1.39

(s, 9 H, 3 CH₃) ppm. ¹³C NMR (50 MHz, CDCl₃): δ = 155.52

(CO), 79.75 [C(CH₃)₃], 44.22 (CH₂Cl), 42.61 (CH₂CH₂Cl), 28.46

[(CH₃)₃] ppm. MS (ESI): m/z = 180.24 [M + 1]⁺. C₇H₁₄ClNO₂

(179.65): calcd. C 46.80, H 7.86; found C 46.78, H 7.82.

2-[5-(4-Benzoylamino-9,10-dioxo-3-phenoxyanthracen-1-yloxy)pen-

phtyl]malonic Acid (D2-ac): The product D2-ac was prepared ac-

cording to the general procedure C using the following quantities:

D2-mal (1.00 g, 1.51 mmol), dioxane (10 mL), 1  KOH (10 mL) to

obtain D2-ac (0.86 g, 97%) as a yellow solid. R_f= (EtOAc) = 0.1.

¹H NMR (200 MHz, CDCl₃): δ = 8.38–8.29 (m, 2 H, Ar-H), 8.11–

7.87 (m, 2 H, Ar-H), 7.64–7.29 (m, 8 H, Ar-H), 6.87 (m, 2 H, Ar-

H), 6.25 (m, 1 H, Ar-H), 4.15 (m, 1 H, CH), 3.34 (m, 2 H, OCH₂),

1.96–1.84 (m, 4 H, OCH₂CH₂, CH₂CH), 1.42–1.35 (m, 4 H,

2ϫCH₂) ppm. ¹³C NMR (50 MHz, CDCl₃): δ = 187.49, 181.97

(2ϫCO), 169.84, 169.41, 163.86 (3 CO), 162.51, 153.25, 137.44,

134.85, 134.39, 134.16, 132.19, 132.56, 130.56, 129.73, 129.32,

128.25, 127.42, 127.34, 127.25, 126.22, 126.04, 120.89, 111.58,

107.94, 107.88 (Ar-C), 71.22, 67.28 (OCH₂), 51.25 (CH), 27.95

(OCH₂CH₂), 27.66 (CH₂CH), 27.23 (CH₂CH₂CH), 27.08

(CH₂CH₂CH₂) ppm. MS (ESI): m/z = 608.61 [M + 1]⁺. C₃₅H₂₉NO₉

(607.62): calcd. C 69.19, H 4.81; found C 69.08, H 4.75.

Diethyl 2-[2-(tert-Butoxycarbonylamino)ethyl]malonate (11): The

product 11 was prepared according to the general procedure A

using the following quantities: diethyl malonate (1.30 mL,

8.38 mmol), sodium hydride 60% (0.34 g, 8.38 mmol) and 10 (1.5 g,

8.39 mmol) in dry THF (25 mL). The crude was purified by FCC

(EtOAc/petroleum ether, 3:1, R_f= 0.35) to afford 11 (1.95 g, 84%)

as a yellow oil. ¹H NMR (200 MHz, CDCl₃): δ = 4.12 (q, J =

7.2 Hz, 4 H, 2 CH₂CH₃), 3.14 (m, 3 H, CHCO, CONHCH₂), 2.30

(t, J = 7.4 Hz, 2 H, CH₂CH), 1.39 (s, 9 H, 3 CH₃), 1.19 (t, J =

7.2 Hz, 6 H, 2 CH₂CH₃) ppm. ¹³C NMR (50 MHz, CDCl₃): δ =

168.36 (2 CO), 149.44 (CONH), 82.73 [C(CH₃)₃], 61.46 (2

CH₂CH₃), 50.09 (CHCO), 44.81 (CH₂CH₂CH), 27.84 [(CH₃)₃],

21.51 (CH₂CH), 14.04 (2 CH₂CH₃) ppm. MS (ESI): m/z = 304.35

[M + 1]⁺. C₁₄H₂₅NO₆(303.35): calcd. C 55.43, H 8.31; found C

55.38, H 8.19.

Synthesis of NatD2-p: The product NatD2-p was prepared accord-

ing to the general procedure D using the following quantities: D2-

ac (0.70 g, 1.16 mmol), NMM (0.38 mL, 3.34 mmol), DMTMM

(0.94 g, 3.34 mmol) and protected amino-lactose 7 (1.18 g,

2.32 mmol) in THF (25 mL). The product was purified by FCC

(EtOAc/petroleum ether, 2:5, R_f= 0.37) to afford NatD2-p (1.80 g,

97%) as a yellow solid ¹H NMR (200 MHz, CDCl₃): δ = 8.30–8.19

(m, 2 H, Ar-H), 7.81–7.72 (m, 2 H, Ar-H), 7.43–7.15 (m, 8 H, Ar-

H), 6.84 (m, 2 H, Ar-H), 6.31 (m, 1 H, Ar-H), 4.69 (m, 2 H), 4.52

(m, 2 H), 4.38 (m, 2 H), 4.35–4.22 (m, 2 H) 4.17–3.95 (m, 13 H),

3.75–3.48 (m, 10 H), 3.43–3.42 (2 s, 12 H, 2 OCH₃), 1.88–1.65 (m,

4 H, OCH₂CH₂, CH₂CH), 1.49, 1.44, 1.42, 1.39 [4 s, 24 H, 4

C(CH₃)₂], 1.36–1.27 [m, 16 H, 2 CH₂, C(CH₃)₂] ppm. ¹³C NMR

(50 MHz, CDCl₃): 187.14, 181.98 (2 CO), 170.97, 170.77, 164.08 (3

CO), 162.29, 152.94, 136.68, 134.67, 134.42, 134.10, 132.19, 130.42,

129.64, 129.18, 128.33, 127.59, 127.16, 127.41, 125.81, 120.79,

111.44, 110.18, 108.66 (Ar-C), 108.42, 107.88, 107.21 [C(CH₃)₂],

68.80 (OCH₂), 54.92 [C(OCH₃)₂], 50.33 (CH), 33.92, 31.07, 29.05,

28.28, 27.69, 27.40, 27.10, 26.42, 24.84, 24.11 [C(CH₃)₂, CH₂] ppm;

see Table 7 for the glycidic moiety. UV/Vis: λ_max= 415 nm; ε =

21597 ^–1cm^–1. MS (ESI): m/z = 1586.88 [M + 1]⁺. C₈₁H₁₀₇N₃O₂₉

(1586.74): calcd. C 61.31, H 6.80; found C 61.25, H 6.71.

Diethyl 2-(2-Aminoethyl)malonate (12): Trifluoroacetic acid (90%)

was cooled to –15 °C and then 11 (1.00 g, 3.30 mmol-%) was added

neat. The solution was then stirred at –15 °C for 3 h. After this

time, the mixture was transferred slowly using a cannula into a

saturated aqueous solution of NH₄OH cooled to –10 °C and then

extracted with DCM. The combined organic phases were dried,

filtered and concentrated under reduced pressure. The residue was

purified by precipitation in water to afford 12 (0.66, 91%). ¹H

NMR (200 MHz, CDCl₃): δ = 4.01 (q, J = 7.2 Hz, 4 H, 2

CH₂CH₃), 3.21 (m, 3 H, CH, CONHCH₂), 2.39 (t, J = 7.3 Hz, 2

H, CH₂CH), 1.19 (t, J = 7.2 Hz, 6 H, 2 CH₃) ppm. ¹³C NMR

(50 MHz, CDCl₃): δ = 168.48 (2 CO), 61.49 (2 CH₂CH₃), 50.15

(CHCO), 44.80 (CH₂CH₂CH), 21.60 (CH₂CH), 14.04 (2

CH₂CH₃) ppm. MS (ESI): m/z = 204.41 [M + 1]⁺. C₉H₁₇NO₄

(203.24): calcd. C 53.19, H 8.43; found C 53.07, H 8.32.

Synthesis of NatD2: The product NatD2 was prepared according

to the general procedure B using the following quantities: NatD2-

p (1.0 g, 0.63 mmol) in TFA (15 mL) to afford NatD2 (0.78 g, 98%)

as a yellow powder as a mixture of α- and β-pyranosic anomers in

the ratio of 50:50 calculated on the basis of the relative C-1 signal

1

intensities. Selected H NMR (200 MHz, D₂O): δ = 8.35–8.27 (m,

2 H, Ar-H, both anomers), 7.81–7.69 (m, 2 H, Ar-H, both ano- 3-(N-Ethyl-N-{4Ј-[(4ЈЈ-nitrophenyl)azo]phenyl}amino)propanoic

mers), 7.41–7.11 (m, 8 H, Ar-H, both anomers), 6.88 (m, 2 H, Ar-

H, both anomers), 6.29 (m, 1 H, both anomers), 5.11–4.56 (m, 4

H, both anomers), 4.33–4.23 (m, 9 H, both anomers), 3.99–3.79

(m, 12 H, both anomers), 3.75–3.40 (m, 6 H, both anomers), 1.87–

1.79 (m, 4 H, OCH₂CH₂, CH₂CH, both anomers), 1.48–1.36 (m,

4 H, 2 CH₂, both anomers) ppm. ¹³C NMR(50 MHz, D₂O): δ =

187.49–181.97 (2 CO, both anomers), 169.84–169.41, 163.86 (CO),

Acid (D3-ac): A 37% solution of HCl (l0 mL) was added to a solu-

tion of D3 (3 g, 9.23 mmol) in AcOH (15 mL) and the resulting

mixture was stirred at 90 °C for 3 h. The acid was removed under

reduced pressure and the residue was dissolved in DCM (30 mL).

The organic solution was washed with an aqueous solution of 3 

NaOH (3ϫ25 mL) and the aqueous solution was acidified with a

1  HCl solution to pH = 2 and extracted with DCM (3ϫ30 mL).

162.51, 153.25, 137.44, 134.39, 134.16, 132.19, 130.56, 129.73, The organic solution was dried with Na₂SO₄and filtered. The sol-

129.32, 128.25, 127.42, 127.34, 127.25, 126.22, 126.04, 120.89, vent was removed under reduced pressure to afford D3-ac (3.1 g,

1

111.58, 107.94, 107.88 (Ar-C), 67.28 (OCH₂), 51.25 (CH), 30.95

98%) as a red solid. H NMR (200 MHz, [D₆]acetone): δ = 8.38,

Eur. J. Org. Chem. 2009, 2748–2764

www.eurjoc.org

2761

J. Isaad, M. Rolla, R. Bianchini

FULL PAPER

6.90 (AAЈXXЈ system, 4 H, Ar-H), 7.91, 7.84 (AAЈXXЈ system, 4 H, NHCH₂CH₂), 2.29 (m, 2 H, CH₂CHCO), 1.48–1.24 [m, 39 H,

H, Ar-H), 3.85 (t, J = 6.8 Hz, 2 H, NCH₂CH₂), 3.65 (q, J = 7.1 Hz, C(CH₃)₃, CH₃] ppm. ¹³C NMR (50 MHz, CDCl₃): δ = 172.66 (2

2 H, NCH₂CH₃), 2.72 (t, J = 6.8 Hz, 2 H, CH₂CO), 1.24 (t, J = CO), 170.76 (CO), 156.50 (Ar-C), 150.07 (Ar-C), 147.26 (Ar-C),

7.1 Hz, 3 H, CH₃) ppm. ¹³C NMR (50 MHz, [D₆]acetone): δ = 143.52 (Ar-C), 126.27 (Ar-C), 124.57 (Ar-C), 122.48 (Ar-C), 111.43

169.69 (CO), 152.25 (Ar-C), 150.90 (Ar-C), 146.70 (Ar-C), 143.66 (Ar-C), 110.42, 110.24, 108.40 [3 C(CH₃)₃], 56.84 [2 O(CH₃)₂],

(Ar-C), 126.87–126.24 (Ar-C), 124.90 (Ar-C), 122.15 (Ar-C), 56.49 (CH), 46.79 (NCH₂CH₂), 45.84 (NCH₂CH₃), 34.34

113.47–111.32 (Ar-C), 47.19 (NCH₂CH₂), 46.56 (NCH₂CH₃), (CH₂CH₂CH), 31.03 (NCH₂CH₂), 29.82 (CH₂CH), 28.26, 27.32,

34.51 (NCH₂CH₂), 12.36 (CH₃) ppm. MS (ESI): m/z = 343.34 [M

+ 1]⁺. C₁₇H₁₈N₄O₄(342.35): calcd. C 59.64, H 5.30; found C 59.61,

H 5.27.

26.55, 26.41, 25.83, 24.23 [C(CH₃)₂], 12.62 (CH₃) ppm; see Table 7

for the glycidic moiety and. UV/Vis: λ_max= 457 nm; ε =

85192 ^–1cm^–1. MS (ESI): m/z = 1450.71 [M + 1]⁺. C₆₈H₁₀₃N₇O₂₇

(1450.59): calcd. C 56.30, H 7.16; found C 56.25, H 7.04.

3-Ethyl-(4-azo-4Ј-nitrophenylphenylamino)propanamide Diethyl Ma-

lonate (D3-mal): NEt₃(0.62 mL, 4.38 mmol) and ethyl chloro-

formate (0.42 mL, 4.38 mmol) were added to a solution of D3-ac

(1.5 g, 2.92 mmol) in dry THF (25 mL), and the resulting mixture

was stirred at 0 °C for 30 min. The derivative 11 (0.59 g, 2.92 mmol)

was added and the resulting solution was stirred at room tempera-

ture for 20 h. TLC analysis (EtOAc/petroleum ether, 1:2) revealed

the formation of a major product (R_f= 0.67). The crude solution

was diluted with chloroform (15 mL) and washed with water

(3ϫ20 mL). The organic phase was dried with Na₂SO₄, concen-

trated under reduced pressure and the resulting residue was puri-

fied by flash chromatography (EtOAc/petroleum ether, 1:2, R_f=

Synthesis of NatD3: The product NatD3 was prepared according

to the general procedure B using the following quantities: NatD3-

p (1.3 g, 1.62 mmol) and TFA (10 mL) to give NatD3 (1.58 g, 99%)

as an orange powder as a mixture of α- and β-pyranosic anomers

in a ratio of 40:60 calculated on the basis of the relative C-1 signal

intensities. Selected ¹H NMR (200 MHz, D₂O): δ = 8.37–7.91

(AAЈXXЈ system, 4 H, Ar-H, both anomers), 7.90–6.77 (AAЈXXЈ

system, 4 H, Ar-H, both anomers), 5.07–4.59 (m, 4 H, both ano-

mers), 4.24–4.17 (m, 8 H, both anomers), 3.89–3.76 (m, 14 H, both

anomers), 3.62 (m, 9 H, both anomers), 2.63 (t, J = 7.00 Hz, 2

H, NHCH₂CH₂, both anomers), 2.29 (m, 2 H, CH₂CHCO, both

1

0.67) to yield D3-mal (1.74 g, 89%) as an orange solid. H NMR

anomers), 1.22 (m, J = 7.2 Hz, 3 H, CH₃, both anomers) ppm. ¹³

C

(200 MHz, CDCl₃): δ = 8.36–7.95 (AAЈXXЈ system, 4 H, Ar-H),

7.95–6.82 (AAЈXXЈ system, 4 H, Ar-H), 4.22 (q, J = 7.3 Hz, 4 H,

NMR (50 MHz, D₂O₃): δ = 171.45–170.65 (CO), 155.55 (Ar-C),

150.98 (Ar-C), 147.20 (Ar-C), 143.54 (Ar-C), 126.66–126.24 (Ar-

2 CH₂CH₃), 3.88 (t, J = 6.9 Hz, 2 H, NCH₂CH₂), 3.64–3.49 (m, 5 C), 124.61 (Ar-C), 122.39 (Ar-C), 113.31–111.96 (Ar-C), 55.86

H, NCH₂CH₃, NHCH₂, CHCO), 2.61 (t, J = 6.9 Hz, 2 H, (CH), 47.07, 43.14 (NCH₂CH₂), 45.02 (NCH₂CH₃), 34.66

NCH₂CH₂), 2.31 (m, 2 H, CH₂CHCO), 1.26 (m, 9 H, 3 CH₃) ppm. (CH₂CH₂CH), 31.62 (NCH₂CH₂), 29.82 (CH₂CH), 12.56

¹³C NMR (50 MHz, CDCl₃): δ = 170.67 (CO), 156.52 (Ar-C), (CH₃) ppm; see Table 8 for the glycidic moiety. UV/Vis: λ_max

150.98 (Ar-C), 147.20 (Ar-C), 143.54 (Ar-C), 126.66–126.24 (Ar-

C), 124.31 (Ar-C), 122.39 (Ar-C), 113.31–111.96 (Ar-C, 61.92 (2

=

457 nm; ε = 85585 ^–1cm^–1. MS (ESI): m/z = 1118.14 [M + 1]⁺.

C₄₆H₆₇N₇O₂₅(1118.07): calcd. C 49.42, H 6.04; found C 49.33, H

CH₂CH₃), 55.86 (CH), 46.14 (NCH₂CH₂), 45.50 (NCH₂CH₃), 6.01.

34.65 (CH₂CH₂CH), 31.31 (NCH₂CH₂), 29.82 (CH₂CH), 14.68 (2

5-Bromopentyl 2-(N-Ethyl-N-{4Ј-[(2ЈЈ-chloro-4ЈЈ-nitrophenyl)-

CH₂CH₃), 12.55 (CH₃) ppm. MS (ESI): m/z = 528.42 [M + 1]⁺.

phazo]phenyl}amino)ethyl Ether (D4-Eth): The product D4-Eth was

prepared according to the general procedure A using the following

quantities: D4 (1.00 g, 3.72 mmol), KOH (1.05 g, 18.60 mmol), 18-

crown-6 ether (0.01 equiv.) and dibromopentane (1.02 mL,

7.44 mmol) in THF (25 mL). The crude product was purified by

FCC (EtOAc/petroleum ether, 3:1, R_f= 0.51) to afford D4-Eth

(1.44 g, 78 %). ¹H NMR (200 MHz, CDCl₃): δ = 8.33–7.95

C₂₆H₃₃N₅O₇: calcd. C 59.19, H 6.30; found C 59.07, H 6.21.

3-Ethyl-(4-azo-4Ј-nitrophenylphenylamino)propanamide Malonic

Acid (D3-Diac): The product D3-Mal-diac was prepared according

to the general procedure C using the following quantities: D3-mal

(1.70 g, 3.22 mmol) in dioxane (10 mL), a solution of 1  KOH

(10 mL) to afford D3-diac (1.50 g, 98%) as a red crystal. ¹H NMR

(200 MHz, CDCl₃): δ = 8.37, 7.93 (AAЈXXЈ system, 4 H, Ar-H), (AAЈXXЈ system, 4 H, Ar-H), 7.91–6.77 (AAЈXXЈ system, 3 H,

7.87, 6.75 (AAЈXXЈ system, 4 H, Ar-H), 3.88 (t, J = 6.8 Hz, 2 H, Ar-H), 3.64–3.36 (m, 10 H, 2 CH₂O, CH₂CH₂N, CH₃CH₂N,

NCH₂CH₂), 3.63–3.49 (m, 5 H, NCH₂CH₃, NHCH₂, CHCO), 2.62 CH₂Br), 1.84 (m, 2 H, CH₂), 1.54 [m, 4 H, (CH₂)₂], 1.25 (t, J =

(t, J = 6.8 Hz, 2 H, NCH₂CH₂), 2.31 (m, 2 H, CH₂CHCO),1.24 7.0 Hz, 3 H, CH₃) ppm. ¹³C NMR (50 MHz, CDCl₃): δ = 153.00

(m, J = 7.0 Hz, 3 H, CH₃) ppm. ¹³C NMR (50 MHz, CDCl₃): δ =

(Ar-C), 151.73 (Ar-C), 146.87 (Ar-C), 144.19 (Ar-C), 133.70 (Ar-

170.47 (CO), 156.52 (Ar-C), 150.98 (Ar-C), 147.21 (Ar-C), 143.67 C), 126.87 (Ar-C), 125.85 (Ar-C), 122.49 (Ar-C), 117.92 (Ar-C),

(Ar-C), 126.66–126.26 (Ar-C), 124.61 (Ar-C), 122.38 (Ar-C), 111.61 (Ar-C), 71.40 (OCH₂), 68.28 (CH₂O), 52.07 (NCH₂CH₂),

113.33–111.96 (Ar-C), 55.86 (CH), 46.14 (NCH₂CH₂), 45.50

(NCH₂CH₃), 34.66 (CH₂CH₂CH), 31.24 (NCH₂CH₂), 29.82 (OCH₂CH₂), 25.94 [OCH₂CH₂CH₂], 12.4 (CH₃) ppm. MS (ESI):

(CH₂CH), 12.67 (CH₃) ppm. MS (ESI): m/z = 472.23 [M + 1]⁺. m/z = 497.13 [M + 1]⁺. C₂₁H₂₆BrClN₄O₃calcd. C 50.67, H 5.26;

46.33 (NCH₂CH₃), 32.46 (CH₂Br), 29.50 (CH₂CH₂Br), 28.79

C₂₂H₂₅N₅O₇(471.47): calcd. C 56.05, H 5.34; found C 56.01, H found C 50.44, H 5.17.

5.22.

Diethyl 2-{5Ј-[2ЈЈ-(N-Ethyl-N-{4ЈЈЈ-[(2ЈЈЈЈ-chloro-4ЈЈЈЈ-nitrophenyl)-

Synthesis of NatD3-p: The product NatD3-p was prepared accord-

ing to the general procedure D using the following quantities: D3-

diac (1.90 g, 4.03 mmol), N-methylmorpholine (0.9 mL,

phazo]phenyl}amino)ethoxy]pentyl}malonate (D4-mal): The product

D4-mal was prepared according the general procedure E using the

following quantities: D4-Eth (1.00 g, 2.01 mmol), diethyl malonate

8.06 mmol), DMTMM (2.23 g, 8.06 mmol) and amino-lactose 7 (0.3 mL, 2.01 mmol) and 60% NaH (0.08 g, 2.01 mmol) in THF

(47.11 g, 8.06 mmol) in THF (15 mL) to afford NatD3-p (5.32 g,

92%) as a red crystal (R_f= 0.35, EtOAc/petroleum ether, 5:2). H

(15 mL). The product was purified by FCC (EtOAc/petroleum

1

ether, 3:1, R_f= 0.34) to obtain D4-mal (0.90 g, 87%). ¹H NMR

NMR (200 MHz, CDCl₃): δ = 8.33–7.87 (AAЈXXЈ system, 4 H, (200 MHz, CDCl₃): δ = 8.32–7.96 (AAЈXXЈ system, 4 H, Ar-H),

Ar-H), 7.87–6.75 (AAЈXXЈ system, 4 H, Ar-H), 4.67 (m, 2 H), 4.53 7.92–6.78 (AAЈXXЈ system, 3 H, Ar-H), 4.10 (q, J = 7.0 Hz, 4 H,

(m, 2 H), 4.33 (m, 2 H), 4.30–4.17 (m, 2 H), 3.82–3.43 (m, 15 H), 2 CH₂CH₃), 3.61–3.45 (m, 6 H, NCH₂CH₃, NCH₂CH₃,

3.55–3.39 (m, 12 H), 3.37 (s, 12 H, 4 OCH₃), 2.64 (t, J = 6.9 Hz, 2

NCH₂CH₂), 3.34 (m, 3 H, OCH₂, CH), 1.94 (m, 2 H, CH₂CHCO),

2762

www.eurjoc.org

Eur. J. Org. Chem. 2009, 2748–2764

Synthesis of Water-Soluble Large Naturalised Dyes

1.52 (m, 2 H, OCH₂CH₂), 1. 35 (m, 4 H, CH₂CH₂CH, (Ar-C), 133.02 (Ar-C), 126.75 (Ar-C), 125.59 (Ar-C), 122.86–

CH₂CH₂CH₂), 1.25 (m, 9 H, 3CH₃) ppm. ¹³C NMR (50 MHz, 117.93 (Ar-C), 111.71 (Ar-C), 70.55, 67.92 (2 CH₂), 51.25

CDCl₃): δ = 171.61 (2 CO), 153.02 (Ar-C), 151.67 (Ar-C), 146.97

(Ar-C), 144.29 (Ar-C), 133.76 (Ar-C), 126.86 (Ar-C), 125.90 (Ar-

C), 122.50 (Ar-C), 117.92 (Ar-C), 111.59 (Ar-C), 71.49 (OCH₂),

(NCH₂CH₂), 50.33 (CH), 45.88 (NCH₂CH₃), 30.25 (OCH₂CH₂),

28.33 (CH₂CH), 27.13 (CH₂CH₂CH), 25.90 (CH₂), 11.77

(CH₃) ppm; see Table 8 for the glycidic moiety. UV/Vis: λ_max

=

68.29 (CH₂O), 61.05 (2 CH₂CH₃), 57.33 (CH₂CH₂O), 50.65 (CH), 483 nm; ε = 19718 ^–1cm^–1. MS (ESI): m/z = 1167.48 [M + 1]⁺.

46.32 (NCH₂CH₃), 32.46 (OCH₂CH₂), 29.62 (CH₂CH), 26.56 C₄₈H₇₁ClN₆O₂₅(1167.57): calcd. C 49.38, H 6.13; found C 49.37,

(CH₂CH₂CH), 24.04 (CH₂CH₂CH₂), 14.29 (2 CH₃), 12.40 H 6.07.

(CH₃) ppm. MS (ESI): m/z = 577.12 [M + 1]⁺. C₂₈H₃₇ClN₄O₇

(577.08): calcd. C 58.28, H 6.46; found C 58.11, H 6.41.

2-(N-Ethyl-N-{4Ј-[(4ЈЈ-nitrophenyl)azo]phenyl}amino)ethyl (5-Bro-

mopentyl)] Ether (D5-Eth): The product D5-Eth was prepared ac-

2-{5Ј-[2ЈЈ-(N-Ethyl-N-{4ЈЈЈ-[(2ЈЈЈЈ-chloro-4ЈЈЈЈ-nitrophenyl)azo]-

phenyl}phamino)ethoxy]pentyl}malonic Acid (D4-diac): The product

D4-diac was prepared according to the general procedure C using

the following quantities: D4-mal (0.90 g, 1.56 mmol), dioxane

(10 mL) and 1  KOH (10 mL) to obtain D4-diac (0.76 g, 93%) as

a red solid. R_f(EtOAc) = 0.1.¹H NMR (200 MHz, CDCl₃): δ =

8.33–7.95 (AAЈXXЈ system, 4 H, Ar-H), 7.91–6.77 (AAЈXXЈ sys-

cording to the general procedure A using the following quantities:

D5 (1.0 g, 3.18 mmol), KOH (0.715g, 12.73 mmol), 18-crown-6

ether (0.01 equiv.) and dibromopentane (1.30 mL, 9.54 mmol) in

THF (10 mL) to yield D5-Eth (1.15g, 78%) as a red solid. R_f(hex-

ane/EtOAc, 5:1) = 0.79. ¹H NMR (200 MHz, CDCl₃): δ = 8.33–

7.93 (AAЈXXЈ system, 4 H, Ar-H), 7.87–6.77 (AAЈXXЈ system, 4

H, Ar-H), 3.63–3.36 (m, 10 H, 2 CH₂O, CH₂CH₂N, CH₃CH₂N,

tem, 3 H, Ar-H), 3.71 (m, 6 H, NCH₂CH₃, NCH₂CH₃, CH₂Br), 1.84 (m, 2 H, CH₂), 1.54 [m, 4 H, (CH₂)₂], 1.25 (t, J =

NCH₂CH₂), 3.41 (m, 3 H, OCH₂, CH), 1.97 (m, 2 H, CH₂CHCO), 7.0 Hz, 3 H, CH₃) ppm. ¹³C NMR (50 MHz, CDCl₃): δ = 156.62

1.55 (m, 2 H, OCH₂CH₂), 1. 39 (m. 4 H, CH₂CH₂CH, (Ar-C), 151.47 (Ar-C), 147.12 (Ar-C), 143.41 (Ar-C), 126.29 (Ar-

CH₂CH₂CH₂), 1.24 (t, J = 6.9 Hz, 3 H, CH₃) ppm. ¹³C NMR C), 124.37 (Ar-C), 122.46 (Ar-C), 111.40 (Ar-C), 71.25 (OCH₂),

(50 MHz, CDCl₃): δ = 169.87 (2 CO), 152.90 (Ar-C), 152.44 (Ar-

C), 147.09 (Ar-C), 143.87 (Ar-C), 133.02 (Ar-C), 126.75 (Ar-C),

125.60 (Ar-C), 122.87–117.94 (Ar-C), 111.71 (Ar-C), 70.88

68.46 (CH₂O), 50.51 (NCH₂CH₂), 46.14 (NCH₂CH₃), 33.88

(CH₂Br), 32.67 (CH₂CH₂Br), 29.00 (OCH₂CH₂), 25.04

(OCH₂CH₂CH₂), 12.4 (CH₃) ppm. MS (ESI): m/z = 463.21 [M +

(OCH₂), 68.36 (CH₂O), 51.24 (NCH₂CH₂), 50.33 (CH), 45.87 1]⁺. C₂₁H₂₇BrN₄O₃(463.37): calcd. C 54.43, H 5.87; found C 54.33,

(NCH₂CH₃), 30.24 (OCH₂CH₂), 27.94 (CH₂CH), 27.11

(CH₂CH₂CH), 25.90 (CH₂CH₂CH₂), 11.77 (CH₃) ppm. MS (ESI):

m/z = 521.27 [M + 1]⁺. C₂₄H₂₉ClN₄O₇(520.97): calcd. C 55.33, H

5.61; found C 55.21, H 5.54.

H 5.76.

Diethyl 2-{5Ј-[2ЈЈ-(N-Ethyl-N-{4ЈЈЈ-[(4ЈЈЈЈ-nitrophenyl)azo]phenyl}-

amino)ethoxy]pentyl}malonate (D5-mal): The product D5-Mal was

prepared according to the general procedure E using the following

quantities: diethyl malonate (0.33 mL, 2.16 mmol), 60% sodium

hydride (0.087g, 2.16 mmol) and D5-Eth (1.00g, 2.16 mmol) in dry

THF (15 mL). The product was purified by FCC (EtOAc/petro-

leum ether, 1:5, R_f= 0.39) to afford D5-mal (1.042g, 89%) as a

Synthesis of NatD4-p: The product NatD4-p was prepared accord-

ing to the general procedure D using the following quantities: D4-

diac (0.70 mL, 1.35 mmol), NMM (0.44 g, 4.04 mmol), DMTMM

(1.12 g, 4.04 mmol) and protected amino-lactose 7 (1.37 g,

2.7 mmol) in THF (25 mL). The product was purified by FCC

(EtOAc/petroleum ether, 5:1, R_f= 0.44) to afford NatD4-p (1.80,

1

red crystal. H NMR (200 MHz, CDCl₃): δ = 8.33–7.93 (AAЈXXЈ

system, 4 H, Ar-H), 7.87–6.77 (AAЈXXЈ system, 4 H, Ar-H), 4.19

(q, J = 7.0 Hz, 4 H, 2 CH₂CH₃), 3.61–3.26 (m, 9 H, CH₂OCH₂,

CH₂CH₂O, NCH₂CH₃, O CH₂, CH CO), 1. 90 (m, 2 H,

1

97%) as an orange solid H NMR (200 MHz, CDCl₃): δ = 8.39–

7.93 (AAЈXXЈ system, 4 H, Ar-H), 7.93–6.78 (AAЈXXЈ system, 3

H, Ar-H), 4.65 (m, 2 H), 4.52 (m, 2 H), 4.33 (m, 2 H), 4.25 (m, 2 CH₂CHCO), 1.57 (m, 2 H, OCH₂CH₂), 1.35 (m, 4 H, CH₂CH₂CH,

H), 4.14–3.85 (m, 12 H), 3.79–3.42 (m, 17 H), 3.40–3.39 (s, 12 H, CH₂CH₂CH₂), 1.25 (m, 9 H, 3CH₃) ppm. ¹³C NMR (50 MHz,

4 OCH₃), 1.98 (m, 2 H, CH₂CHCO), 1.57 (m, 2 H, OCH₂CH₂),

1.49–1.26 (various signals, 40 H) 1.22 (t, J = 7.1 Hz, 3 H,

CDCl₃): δ = 169.32 (2 CO), 156.57 (Ar-C), 151.50 (Ar-C), 147.13

(Ar-C), 143.34 (Ar-C), 126.42 (Ar-C), 124.60 (Ar-C), 122.42 (Ar-

CH₃) ppm. ¹³C NMR (50 MHz, CDCl₃): δ = 173.09 (2 CO), 153.04 C), 111.44 (Ar-C), 71.42 (OCH₂), 68.34 (CH₂O), 61.39 (2

(Ar-C), 151.66 (Ar-C), 146.99 (Ar-C), 144.28 (Ar-C), 133.76 (Ar-

C), 126.85 (Ar-C), 125.90 (Ar-C), 122.51–117.94 (Ar-C), 111.66

(Ar-C), 110.40, 110.19, 108.39 [C(CH₃)₂], 71.58, 68.28 (2 OCH₂),

CH₂CH₃), 52.08 (CH), 50.53 (CH₂CH₂O), 46.20 (NCH₂CH₃),

29.52 (OCH₂CH₂), 28.80 (CH₂CH), 27.27 (CH₂CH₂CH), 25.96

(CH₂CH₂CH₂), 14.28 (2 CH₃), 12.42 (CH₃) ppm. MS (ESI): m/z =

53.16 (NCH₂CH₂), 50.72 (CH), 46.36 (NCH₂CH₃), 36.40 543.42 [M + 1]⁺. C₂₈H₃₈N₄O₇(542.63): calcd. C 61.98, H 7.06;

(OCH₂CH₂), 29.71 (CH₂CH), 29.42, 28.29, 27.41, 26.59, 26.41,

26.16, 25.82, 24.26 [C(CH₃)₂], 12.40 (CH₃) ppm; see Table 7 for the

glycidic moiety. UV/Vis: λ_max= 483 nm; ε = 19333 ^–1cm^–1S

(ESI): m/z = 1499.77 [M + 1]⁺. C₇₀H₁₀₇ClN₆O₂₇(1500.09): calcd.

C 56.05, H 7.19; found C 56.17, H 7.23.

found C 61.89, H 7.01.

2-{5Ј-[2ЈЈ-(N-Ethyl-N-{4ЈЈЈ-[(4ЈЈЈЈ-nitrophenyl)azo]phenyl}amino)-

ethoxy]pentyl}malonic Acid (D5-diac): The product D5-diac was

prepared according to the general procedure C using the following

quantities: D5-Mal (1.00 g, 1.84 mmol), dioxane (10 mL) and 1 

KOH (10 mL) to obtain D5-diac (0.83g, 92%) as a red solid. R_f

(EtOAc) = 0.1. ¹H NMR (200 MHz, CDCl₃): δ = 8.33–7.93

(AAЈXXЈ system, 4 H, Ar-H), 7.87–6.77 (AAЈXXЈ system, 4 H, Ar-

H), 3.61–3.26 (m, 9 H, CH₂OCH₂, CH₂CH₂O, NCH₂CH₃, OCH₂,

Synthesis of NatD4: The product NatD4 was prepared according

to the general procedure B using the following quantities: NatD4-

p (1.2 g, 0.55 mmol) and TFA (10 mL) to afford NatD4 (1.0 g,

98%) as a red solid. ¹H NMR (200 MHz, D₂O): δ = 8.40–7.92

(AAЈXXЈ system, 4 H, Ar-H), 7.91–6.65 (AAЈXXЈ system, 3 H, CHCO), 1.90 (m, 2 H, CH₂CHCO), 1.57 (m, 2 H, OCH₂CH₂), 1.35

Ar-H), 5.07–4.58 (m, 4 H), 4.24–4.17 (m, 8 H), 3.93–3.82 (m, 12 (m, 4 H, CH₂CH₂CH, CH₂CH₂CH₂), 1.25 (t, J = 7.0 Hz, 3 H,

H), 3.66–3.56 (m, 6 H, NCH₂CH₃, NCH₂CH₃, NCH₂CH₂), 3.44– CH₃) ppm. ¹³C NMR (50 MHz, CDCl₃): δ = 170.03 (2 CO), 156.13

3.40 (m, 7 H), 1.96 (m, 2 H, CH₂CHCO), 1.54 (m, 2 H, (Ar-C), 152.20 (Ar-C), 147.11 (Ar-C), 142.99 (Ar-C), 126.59 (Ar-

OCH₂CH₂), 1.38 (m, 4 H, CH₂CH₂CH, CH₂CH₂CH₂), 1.26 (t, J C), 124.58 (Ar-C), 122.19 (Ar-C), 111.95 (Ar-C), 70.91 (OCH₂),

= 6.8 Hz, 3 H, CH₃) ppm. ¹³C NMR (50 MHz, D₂O): δ = 172.22,

169.86 (2 CO), 152.59 (Ar-C), 152.43 (Ar-C), 147.08 (Ar-C), 143.86 29.94 (OCH₂CH₂), 28.89 (CH₂CH), 27.13 (CH₂CH₂CH₂), 25.90

68.34 (CH₂O), 51.32 (CH), 50.44 (NCH₂CH₂), 45.98 (NCH₂CH₃),

Eur. J. Org. Chem. 2009, 2748–2764

www.eurjoc.org

2763

J. Isaad, M. Rolla, R. Bianchini

FULL PAPER

(CH₂CH₂CH), 11.87 (CH₃) ppm. MS (ESI): m/z = 487.31 [M +

1]⁺. C₂₄H₃₀N₄O₇(486.52): calcd. C 59.25, H 6.22; found C 59.23,

H 6.19.

CH₂CH₃) ppm. ¹³C NMR (50 MHz, CDCl₃): δ = 185.10,181.56 (2

CO), 154.14, 151.00, 139.94, 134.48, 133.79, 133.19, 132.97, 130.26,

126.74, 126.24, 125.46, 120.17, 117.69, 113.34, 112.52, 69.25

(OCH₂), 61.29 (CH₂CH₃), 14.34 (CH₃) ppm. MS (ESI): m/z =

418.32 [M + 1]⁺. C₂₄H₁₉NO₆(417.42): calcd. C 69.06, H 4.59;

found C 68.97, H 4.49.

Synthesis of NatD5-bp: The product NatD5-bp was prepared ac-

cording to the general procedure D using the following quantities:

D5-diac (0.80 g, 2.54 mmol), NMM (0.84 g, 7.64 mmol), DMTMM

(2.11 g, 7.64 mmol) and protected amino-lactose 7 (0.106 g,

4.44 mmol) in THF (20 mL). The product was purified by FCC

(EtOAc/petroleum ether, 10:3, R_f= 0.39) to afford NatD5-bp

(3.38g, 92%) as a red solid. ¹H NMR (200 MHz, CDCl₃): δ = 8.34–

7.92 (AAЈXXЈ system, 4 H, Ar-H), 7.91–6.87 (AAЈXXЈ system, 4

H, Ar-H), 4.66 (m, 2 H), 4.52 (m, 2 H), 4.33 (m, 2 H), 4.29–4.18

(m, 2 H), 4.14–3.95 (m, 12 H), 3.81–3.43 (m, 17 H), 3.42–3.38 (s,

12 H, 4 OCH₃), 1.98 (m, 2 H, CH₂CHCO), 1.55 (m, 2 H,

OCH₂CH₂), 1.49–1.24 (various signals, 40 H), 1.21 (t, J = 7.0 Hz,

3 H, CH₃) ppm. ¹³C NMR (50 MHz, CDCl₃): δ = 172.94 (CO),

152.73 (Ar-C), 151.15 (Ar-C), 146.73 (Ar-C), 144.16 (Ar-C), 126.59

(Ar-C), 125.73 (Ar-C), 122.29 (Ar-C), 117.66–111.64 (Ar-C),

110.13, 109.92, 108.11 [C(CH₃)₂], 73.70, 67.81 (2 OCH₃), 55.82

[C(OCH₃)₂], 53.50 (CH), 50.49 (NCH₂CH₂), 46.18 (NCH₂CH₃),

36.00 (OCH₂CH₂), 29.29, 29.03, 27.9, 26.99, 26.16, 26.01, 25.76,

25.37, 23.79 [C(CH₃)₂, CH₃], 11.84 (CH₃) ppm; see Table 7 for the

glycidic moiety. UV/Vis: λ_max= 501 nm; ε = 19333 ^–1cm^–1. MS

(ESI): m/z = 1465.79 [M + 1]⁺. C₇₀H₁₀₈N₆O₂₇: calcd. C 57.36, H

7.43; found C 57.18, H 7.35.

Acknowledgments

We fully acknowledge the Italvelluti S.p.A company, Montemurlo,

Prato, for funding this research. We also thank Ente Cassa di Ris-

parmio di Firenze for the grants that allowed us to buy the Varian

Cary-4000 spectrophotometer and the mass spectrometer.

[1] H. Zollinger, Color Chemistry, VCH, Weinheim, 1991, p. 139;

H. K. Rouette, Encyclopedia of Textile Finishing, Springer, Zu-

rich, Switzerland, 2000, p. 545.

[2] A. Adak, M. Bandyopadhyay, A. Pal, Colloids. Surf. A: Phy-

sicochem. Eng. Aspects 2005, 254, 165–171; see also, for exam-

ple: C. I. Pearce, J. R. Lloyd, J. T. Guthrie, Dyes Pigm. 2003,

58, 179–196; M. Neamtu, I. Siminiceanu, A. Yediler, A.

Kettrup, Dyes Pigm. 2002, 53, 93–99; C. Galindo, P. Jacques,

A. Kalt, J. Photochem. Photobiol., A 2000, 130, 35–47.

[3] S. Gupta, A. Pal, P. K. Ghosh, M. Bandyopadhyay, J. Environ.

Sci. Health, Part A 2003, 38, 381–397.

[4] R. Anliker, JSDC 1979, 9, 317–326.

[5] Y. Z. Fu, T. Viraraghavan, Bioresour. Technol. 2001, 79, 251–

262.

Synthesis of NatD5: The product NatD5 was prepared according

to the general procedure B using the following quantities: NatD5-

bp (1.5 g, 1.00 mmol) in TFA (10 mL) to afford NatD5 (1.10g,

97%) as a red solid as a mixture of α- and β-pyranosic anomers in

a ratio of 50:50 calculated on the basis of the relative C-1 signal

intensities. Selected ¹H NMR (200 MHz, D₂O): δ = 8.41–7.95

(AAЈXXЈ system, 4 H, Ar-H), 7.92–6.81 (AAЈXXЈ system, 4 H,

Ar-H), 5.12–4.59 (m, 4 H), 4.25–4.19 (m, 8 H), 3.93–3.80 (m, 12

H), 3.62–3.27 (m, 9 H, CH₂OCH₂, CH₂CH₂O, NCH₂CH₃, OCH₂,

CHCO), 3.42–3.39 (m, 4 H), 1.97 (m, 2 H, CH₂CHCO), 1.68 (m,

2 H, OCH₂CH₂), 1.46 (m, 4 H), 1.23 (t, J = 6.9 Hz, 3 H, CH₃) ppm.

¹³C NMR (50 MHz, D₂O): δ = 171.85 (CO), 152.87 (Ar-C), 151.44

(Ar-C), 146.27 (Ar-C), 143.42 (Ar-C), 126.31 (Ar-C), 124.57 (Ar-

C), 122.45 (Ar-C), 117.06–111.38 (Ar-C), 73.08–67.75 (2 CH₂),

55.02 (CH), 50.50 (NCH₂CH₂), 46.16 (NCH₂CH₃), 31.39

(OCH₂CH₂), 29.35 (CH₂CH), 26.31 (CH₂CH₂CH₂) 25.09

(CH₂CH₂CH), 12.43 (CH₃) ppm; see Table 8 for the glycidic moi-

ety. UV/Vis: λ_max= 501 nm; ε = 19715 ^–1cm^–1. MS (ESI): m/z =

1133.47 [M + 1]⁺. C₄₈H₇₂ClN₆O₂₅: calcd. C 50.88, H 6.40; found

C 50.79, H 6.33.

[6] R. Bianchini, G. Bartalucci, G. Catelani, G. Seu, Eur. Pat.,

04005253.4, 2004.

[7] H. Obara, J. Onodera, Chem. Lett. 1979, 201–204.

[8] Encyclopedia Britannica Ondine, 06, 2008.

[9] K. Wojciechowski, A. Wyrebak, Barwinki, Srodki Pomocnicze

2003, 47, 3–17 [Chem. Abstr. 2004, 142, 136560].

[10] G. Bartalucci, R. Bianchini, G. Catelani, F. D’Andrea, L. Gu-

azzelli, Eur. J. Org. Chem. 2007, 588–595.

[11] R. Bianchini, G. Catelani, J. Isaad, R. Cecconi, F. D’Andrea,

E. Frino, M. Rolla, Carbohydr. Res. 2008, 343, 2067–2074.

[12] J. Isaad, R. Bianchini, G. Catelani, E. Frino, M. Rolla, Biore-

sources 2007, 2, 630–637.

[13] R. Bianchini, G. Catelani, J. Isaad, R. Cecconi, F. D’Andrea,

L. Guazzelli, M. Rolla, Eur. J. Org. Chem. 2008, 3, 444–454.

[14] R. Bianchini, G. Catelani, J. Isaad, F. D’Andrea, M. Rolla. F.

Bonacorsi, Eur. Pat. 08423016.6/EP08425016, 2008.

[15] a) J. Yang, X. Fu, Q. Jia, J. Shen, J. B. Biggins, J. Jiang, J. Zhao,

J. J. Schmidt, P. G. Wang, J. S. Thorson, Org. Lett. 2003, 5,

2223–2226; b) A. B. Reitz, R. W. Tuman, C. S. Marchione,

A. D. Jordan Jr., C. R. Bowden, B. E. Marianoff, J. Med.

Chem. 1989, 32, 2110–2116.

[16] P. L. Barili, G. Catelani, F. D’Andrea, F. De Rensis, P. Falcini,

Carbohydr. Res. 1997, 298, 75–84.

Synthesis of D2-x: K₂CO₃(1.25g, 9.06 mmol) was added to a solu-

tion of disperse dye D2 (1.0 g, 3.02 mmol) in acetone (25 mL) and

the resulting mixture was stirred at room temperature for 1.5 h.

Ethyl bromoacetate (1.02 mL, 9.06 mmol) was added and the re-

sulting solution was heated at reflux for 20 h. At the end of the

reaction, the resulting solution was filtered, diluted with water

(40 mL) and the aqueous solution was extracted with chloroform

(4ϫ30 mL). Then the organic phase was dried with Na₂SO₄and

filtered, the filtrate was concentrated under reduced pressure and

the residue (obtained as a red solid) was purified by flash

chromatography (ethyl acetate/petroleum ether, 3:2, R_f= 0.61) to

afford D2-x (0.99 g, 79 %) as a red solid. ¹H NMR (200 MHz,

CDCl₃): δ = 7.85–7.75 (m, 2 H, Ar-H), 7.5–7.0 (m, 5 H, Ar-H),

6.78–6.75 (m, 2 H, Ar-H), 6.30 (m, 1 H, Ar-H), 4.88 (s, 2 H), 4.09

(q, J = 7.1 Hz, 2 H, CH₂CH₃), 1.33 (t, J = 7.1 Hz, 3 H,

[17] M. Kunishima, C. Kawachi, F. Iwasaki, K. Terao, S. Tani, Tet-

rahedron Lett. 1999, 40, 5327–5330.

[18] Z. J. Kamin´ski, B. Kolesin´ska, J. Kolesin´ska, G. Sabatino, M.

Chelli, P. Rovero, M. Baszczyk, M. L. Gówka, A. M. Papini,

J. Am. Chem. Soc. 2005, 127, 16912–16920.

[19] W. C. Still, M. Kahn, A. Mitra, J. Org. Chem. 1978, 43, 2923–

2925.

[20] D. Cardon, Le Monde des teintures naturelles, Belin, Paris,

2003.

[21] D. Cardon, G. du Chatenet, Guide des Teintures Naturelles, De-

lachaux et Niestle, Neuchatel, 1990.

[22] a) K. Bock, C. Pedersen, Adv. Carbohydr. Chem. Biochem.

1984, 42, 193–255; b) K. Boch, H. Thogersen, H. Pedersen,

Annu. Rep. NMR Spectrosc. 1982, 13, 1–57.

Received: March 10, 2009

Published Online: April 27, 2009

2764

www.eurjoc.org

Eur. J. Org. Chem. 2009, 2748–2764

Article Doi

Synthesis of water-soluble large naturalised dyes through double glycoconjugation

DOI: 10.1002/ejoc.200801302

Source and publish data:

Authors:

Article abstract of DOI:10.1002/ejoc.200801302

Full text of DOI:10.1002/ejoc.200801302

Products guided by the article

R&D Labs maybe for 1174752-18-1

Relevant to this article

Hot Product