Efficient synthesis of 1,4-disubstituted triazolyl N-carboxamides via a simple and convenient MCR using basic alumina as solid support

Article abstract of DOI:10.1016/j.tetlet.2013.08.014

A microwave assisted green protocol for the synthesis of 1,4-disubstituted triazolyl N-carboxamides was explored using basic alumina as solid support. The method allows domino Ullmann-type reaction, Click reaction and formation of ester or amide linkages in a single reaction vessel using Cu(phen)(PPh ₃)Br and CMPA as catalyst and basic alumina as solid support in high yield. The protocol did not require addition of any external ligands or base. The method was also found to be equally good for the synthesis of bis triazole adducts.

Full text of DOI:10.1016/j.tetlet.2013.08.014

Accepted Manuscript
Efficient synthesis of 1,4-disubstituted triazolyl N-carboxamides via a simple
and convenient MCR using basic alumina as solid support
Rammyani Pal, Swarbhanu Sarkar, Nivedita Chatterjee, Asish Kumar Sen
PII:
S0040-4039(13)01351-8
DOI:
http://dx.doi.org/10.1016/j.tetlet.2013.08.014
TETL 43371
Reference:
To appear in:
Tetrahedron Letters
Received Date:
Revised Date:
Accepted Date:
15 July 2013
2 August 2013
5 August 2013
Please cite this article as: Pal, R., Sarkar, S., Chatterjee, N., Sen, A.K., Efficient synthesis of 1,4-disubstituted
triazolyl N-carboxamides via a simple and convenient MCR using basic alumina as solid support, Tetrahedron
Letters (2013), doi: http://dx.doi.org/10.1016/j.tetlet.2013.08.014
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Efficient synthesis of 1,4-disubstituted triazolyl N-carboxamides via a
simple and convenient MCR using basic alumina as solid support
Rammyani Pal, Swarbhanu Sarkar, Nivedita Chatterjee, Asish Kumar Sen*
Chemistry Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road,
Kolkata-700 032, India.
*Corresponding author. Tel.: +91-33-24995806; fax: +91-33-24735197; E-mail:
asishksen@yahoo.com; aksen@iicb.res.in (A. K. Sen).
Abstract: A microwave assisted green protocol for the synthesis of 1,4-disubstituted triazolyl
N-carboxamides was explored using basic alumina as solid support. The method allows
domino Ullmann-type reaction, Click reaction and formation of ester or amide linkages in a
single reaction vessel using Cu(phen)(PPh3)Br and CMPA as catalyst and basic alumina as
solid support in high yield. The protocol did not require addition of any external ligands or
base. The method was also found to be equally good for the synthesis of bis triazole adducts.
Key words: Triazolyl N-carboxamide; Domino reaction, Ullmann-type reaction; Click
reaction; ester and amide linkages; Cu(phen)(PPh3)Br; CMPA
Organic reactions executed under non-traditional experimental conditions using less
expensive and recyclable mineral supports (e.g., silica gel, alumina) have attracted great
attention in recent years, primarily to circumvent growing environmental concerns.1 The use
of solid support in microwave-assisted reactions eliminates the need for solvents and also the
requirement of sealed vessels. It also enables microwave-accelerated reactions to occur at
atmospheric pressure and is suitable for preparative scale synthesis.2 Moreover, the
homogenous dispersion of active sites, improved selectivity, enhanced reaction rates, easy
work-up procedure make the solid-supported reactions more attractive than the conventional
solution phase reactions.3
Glycoconjugates, namely glycoproteins, glycolipides or peptidoglycans, have been found
to play crucial roles in varied life processes.4 There are numerous methodologies5 for the
preparation of such glycoconjugates. However, these compounds are often not suitable for
biological studies as the glycosidic bonds are venerable towards chemical and enzymatic
hydrolysis. Synthesis of unnatural glycoconjugates, for example triazolyl glycosides, where
triazole is connected to the sugar unit via an isosteric linkage, may lead to metabolically more
stable analogues and provide a way for the elucidation of biochemical pathways.6 These

unnatural glycosides may also be useful for targeting drugs to specific binding sites.7
Glucose-based inhibitors with NHCO as linker between the sugar and the aromatics
showed potent activity against glycogen phosphorylase which is a validated target against
type 2 diabetes mellitus (Fig. 1a and 1b).8 Successful bioisosteric modification of the amide
with different heteroaromatic compounds leading to compounds having better inhibition
properties are also known8. These motivated us to synthesize a library of compounds where
sugar moieties were linked to 1,2,3-triazoles by NHCO bonds and long hydrophobic chain in
an environmentally benign chemical process (Fig. 1c). The long linking arm is likely to make
the sugar moiety available for better binding with the appropriate receptor.9 Beside this, the
triazole-linked glycoconjugates are also known to display wide range of biological activities
such as anti-HIV,10 anti-allergic,11 antibacterial,12 herbicidal,13 and fungicidal activity;13 act
against the cognate and non-cognate GH114 and also as FimH antagonists.15 Syntheses of
triazole-linked glycoconjugates with varied spacer arms thus may be significant for the
evaluation of such biological activities. These new class of compounds may also influence the
pharmacokinetics and may be used for drug targeting.
OH
OH
OH
H
O
N
Y
Ar
O
HO
HO
Sugar/cyclic-linear
aliphatic
HO
HO
H
Triazole
R
n
N
N
N
OH
N
O
X
N
O
O
N
N
b
n
c
a
Our modified scaffold
Ar
n = 1, 2
FimH anagonists
Glycogen phosphorylase
inhibitor
(n = 2, 7; X = H, O; Y = C, N; R = Sugar, amino acid, aryl)
Figure 1. Carbohydrate linked triazole and triazolyl N-carboxamides.
The synthesis of triazolyl N-carboxamides using traditional methods is a three-step
process. Firstly, the aliphatic or aromatic azides are synthesized followed by copper-mediated
azide–alkyne cyclization. Finally the amide or ester linkages are formed. The traditional
chemical synthesis requires extensive chromatographic purification of intermediates, which is
tedious and time consuming.
Aryl azides are normally prepared by the replacement of diazonium salts or activated aryl
halides with azides.16 Coupling of inactivated aryl halides with sodium azide in presence of
Cu(I)-ligands are also reported.17 However, like other Ullmann-type reaction18 the methods
suffer from the use of high temperature and slow reaction rate. Several other factors such as
nature of the ligand or solvent system are crucial in these processes. But, the main drawback

of this method is the handling of triflic azide.
Therefore, our aim was to develop an environmentally benign chemical process, where
these limitations could be avoided by using recyclable solid support without utilization of any
solvent, additional base or ligands. The one-pot reaction was designed in such a way that
consecutive cyclization and ester/amide bond formation could be achieved in a single pot
without purification of the intermediates (Scheme 1a and 1b). The new protocol allows
domino Ullmann-type reaction, Click reaction and formation of ester or amide linkages in a
single reaction vessel using Cu(phen)(PPh3)Br as catalyst and chloro-phenyl-thio-methylene-
dimethylammonium chloride (CMPA) as coupling agent using basic alumina as solid support.
The use of basic alumina eliminates requirement of any additional solvent and it also act as
base. Moreover, the microwave heating at controlled temperature and pressure reduces the
reaction time drastically.
R1
R1
X
N3
a)
HOOC
R2-NH2 or
N
N
N
N
TMSN3
Cu(I)
n
O
N
N
HOOC
R2
Basic alumina
R2-OH
CMPA
R1
X = Br, I
R1
X
n
n
R3
R3
HOOC
R2-NH2 or
b)
N
O
N
TMSN3
n
N
R3
X
N
R3
N3
R2
N
R2-OH
CMPA
X
HOOC
N
Cu(I)
Basic alumina
n
n
R3 = Sugar or alkyl
X = Br
Scheme 1. Four-component one-pot synthesis of triazolyl-N-carboxamides under microwave
irradiation.
At the outset, we opted iodobenzene and TMSN3 as model reactants and investigated the
feasibility of a ligand-free Ullmann-type reaction to form phenyl azide, under microwave
irradiation (Table 1) at 70 C (100 W). Systematic studies of the reaction conditions in
presence of different solid supports (viz. basic alumina, TiO2, MgO and etc.), and various
copper catalysts19 demonstrated that the use of basic alumina as solid support gave better
yield (Table 1) even in the absence of additional base (triethyl amine, DBU) or without the
requirement of any extra ligand. The effect of different copper catalysts (Fig. 2) were also

investigated (Table 1, entry 1-12). Copper catalysts 1a-b, yielded azido benzene in 52% and
40% (found in repetitive experiments) respectively. Use of catalysts 1c and 1d gave yield of
47% and 53% respectively. Similar observations were noted for thio-copper complex 1e-g.
Use of catalyst 1h was found to be very effective for the particular reaction with an excellent
yield of 88% (Table 1, entry 12).
CuCl
CuCl
Cu-X
1a
N
N
N
X = I
1b X = Br
N
N
1d
CH3
1c
N
N
N
N
N
Cu
Cu
S
S
Cu
S
Cu
Ph3P
Br
1g
1e
1f
1h
Figure 2. Copper catalysts used in the study.
Table 1: Optimization of catalyst towards the synthesis of azido benzene from iodobenzene
and TMSN3 using various solid-supports
Entrya Solid support
Catalyst used Catalyst (mol %) Time (min) Yieldb (%)
A. Without additional base
1
TiO2
10
15
20
15
15
15
15
15
15
15
15
15
8
20
24
24
32
52
40
47
53
64
68
72
88
1a
1a
1a
1a
1a
1b
1c
1d
1e
1f
2
TiO2
10
10
10
10
10
10
10
10
10
10
10
3
TiO2
4
MgO
5
Basic alumina
Basic alumina
Basic alumina
Basic alumina
Basic alumina
Basic alumina
Basic alumina
Basic alumina
6
7
8
9
10
11
12
1g
1h
B. With Et3N as additional base

13
C. With DBU as additional base
14 Basic alumina
Basic alumina
15
15
10
10
88
86
1h
1h
aAll reactions were performed using iodobenzene (1.0 equiv.) and TMSN3 (1.1 equiv.) under
microwave irradiation (100 W, 70 C). Solid support (500 mg-1 gm) was used in each case.
bIsolated yield
Formation of triazoles by Huisgen 1,3-dipolar cycloaddition reaction between terminal
alkynes and organic azides is quite efficient and had proved to be an easy route to 1,4-
disubstituted 1,2,3-triazoles.20 So, organic azides generated in situ, were reacted further with
terminal alkyne (Scheme 1a) for additional 2-3 min (100 C, 60W). The complete conversion
to corresponding triazole was confirmed by TLC. Our next challenge was the consecutive
formation of ester or amide linkages in the same reaction vessel. Usually the ester/amide
bond is formed by the nucleophilic substitution of activated esters generated in situ from the
corresponding acids. Several reagents such as Palomo’s reagent, Castro’s or Taddei’s reagent,
chloro-phenyl-thio-methylene-dimethylammonium chloride, carbodiimide derivatives or
Mukayama’s reagent are used for this purpose.21 Although these reagents are very useful and
efficient, some of these exhibit drawbacks like formation of side products, slow reaction rate,
difficulty during removal, use of organic solvents and low solubility or chemo-selectivity. In
our one-pot protocol, CMPA was used which was added to the reaction mixture and further
irradiated under microwave for an additional period of 5 min. Basic alumina here plays dual
role. It acts as solid support (absorb the organic compounds on their surface) and transmits
microwave irradiation without absorbing or restricting it. It also acts as base by trapping HCl,
generated during the reaction and hence the equilibrium was shifted towards the forward
direction. No additional base was required.
Once we standardized our one-pot domino protocol, the scope of the methodology was
tested with with varied functionalities (Table 2). All the reactions proceeded well and
products were formed in good yield. Both aromatic iodides and bromides (Table 2, entry 1 &
2) participated well in the tandem reaction with TMSN3. However, with NaN3 the yield was
found to be low (Table 2, entry 3).

Table 2: Synthesis of versatile 1,4-disubstituted triazolyl-N-carboxamidesa
Entry
Halide
Azide
Alkyne
Amine/Alcohol
Product (% Yield)b
I
OAc
O
O2N
OAc
HOOC
NO2
AcO
AcO
N
TMSN3
NH2
OAc
O
H
1
O
4a
N
AcO
AcO
N
3a
N
OAc
5a
5a
5a
O
2a
6a (81%)
Br
NO2
2
3
6a (66%)
3a
4a
4a
2b
NaN3
3b
6a (31%)
2a
I
N
H
N
4
5
3a
3a
4a
4a
N
N
MeO2C
NH2
O
2c
MeO2C
5b
6b (77%)
N
I
N
5b
H
N
N
CH3
N
N
2d
O
MeO2C
6c (86%)
CO2H
O2N
H
N
H
H
N
NH2
N
N
6
7
2a
2c
3a
3a
N
O
5c
N
O
O
6d (74%)
4b
4b
H
H
5c
N
N
N
N
N
O
O
6e (79%)
N
H3C
COOH
H
N
PhCH2OH
N
N
N
8
2d
H
N
O
BnO
5d
4c
O
O
6f (73%)
aReactions were performed using organic halide (1.0 equiv.), TMSN3 (1.1 equiv.), 1h (15
mol%), terminal alkynes (1.1 equiv.), organic amines or alcohols (1.0 equiv.), CPMA (1.3
equiv.) and basic alumina (500 mg-1 gm), under microwave irradiation. Products were
characterized by spectroscopic and analytical techniques.
bYield of the isolated pure product; some losses during purification is unavoidable in certain
cases.

The scope of the method was further extended by using different non-aromatic halides
(Table 3). The reactions were found to be equally good for glycosyl bromides (Table 3, entry
1-3) as well as activated alkyl bromides (Table 3, entry 4). Maximum yield of 72% was
obtained with glycosyl bromides (Table 3, entry 2). All compounds could be deacetylated
easily in high yield using sodium methoxide in methanol to obtain the modified scaffold.
Table 3. Synthesis of versatile 1,4-disubstituted triazolyl-N-carboxamidesa
Amine/Alcoh
Entry
Halide
Azide
Alkyne
Product (% Yield)b
ol
OAc
OAc
O
Br
OAc
OAc
OAc
O
AcO
OAc
OAc
1
3a
4a
N
OAc
5a
O
H
N
AcO
AcO
N
N
OAc
2e
O
6g (70%)
OAc
OAc
O
OAc
OAc
H
2
3
2e
2e
3a
3a
4b
4c
5c
H
N
N
N
N
N
O
O
6h (72%)
AcO
OAc
OAc
AcO
O
N
N
N
5d
H
BnO
N
O
O
6i (65%)
Br
OAc
N
4
3a
4a
5a
O
H
N
N
AcO
AcO
N
OAc
O
2f
6j (67%)
aReactions were performed using organic halide (1.0 equiv.), TMSN3 (1.1 equiv.), 1h (15
mol%), terminal alkynes (1.1 equiv.), organic amines or alcohols (1.0 equiv.), CMPA (1.3
equiv.) and basic alumina (500 mg - 1 gm), under microwave irradiation. Products were
characterized by spectroscopic and analytical techniques.
bYield of the isolated pure product; some losses during purification is unavoidable in certain
cases.

Different life processes viz. immunological process, inflammation, cell differentiation and
many signal transductions are governed by multivalent carbohydrate-protein interactions in
human body.22-23 But the molecular basis of such processes are not well known. The
syntheses of multidentate carbohydrate-triazole ligands had been achieved recently.24 For
complex oligosaccharides, the binding efficiency to a specific receptor depends on its cluster
effect and topological arrangement.25 Here we have extended the aforementioned protocol for
the syntheses of bis-triazole derivatives (Fig. 3). It was observed that the protocol described
herein is also well applicable for the synthesis of the bidentate compound 7 and 8, with a
satisfactorily yield (70% and 68% respectively).
Ph
OAc
O
OAc
O
O
N
MeO2C
N
NH
N
NH
AcO
AcO
N
N
N
OAc
OAc
N
O
N
N
AcO
AcO
MeO2C
Ph
NH
NH
N
N
N
O
O
7
8
Figure 3. Synthesis of bidentate1,4-disubstituted triazolyl N-carboxamides.
In conclusion, we have developed a novel one-pot protocol for the synthesis of triazolyl
N-carboxamides.26-27 Unlike previously known processes, the present method excludes the
necessity of using additional ligands for the one-pot domino reaction. Use of basic alumina
eliminates the necessity of solvents and additional bases. Moreover, application of microwave
significantly reduces reaction time. The method was also found to be useful for the synthesis
of complex bidentate molecules.
Acknowledgment
The authors express their gratitude to the Director, IICB for laboratory facilities, the
Council of Scientific and Industrial Research for providing funding and fellowships to R.P.,
S.S. and N.C. Mr. K. Sarkar, Dr. T. Sarkar and Mr. E. Padmanaban are also acknowledged
for recording ESI-MS and NMR spectra.
Supplementary data
Supplementary data (1H and 13C NMR spectra of all new compounds) associated with this

article can be found in the online version, at doi…...
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26. General reaction procedure for the synthesis of triazolyl-N-carboxamides (6a-j): CHCl3
(10-15 mL) was added to a mixture of the aryl halide (1 equiv.), TMSN3 (1.1 equiv.), 1h
(15 mol%.) and basic alumina (500 mg-1 gm) in a round bottomed flask. It was
evaporated to dryness and the mixture was stirred at r.t. for an additional 10–15 min to
ensure efficient mixing. The flask was then fitted with a septum, and was irradiated in the
microwave reactor (70 °C, 100 W) for 6-10 min. The mixture was then cooled and
corresponding alkyne (1.1 equiv.) in CHCl3 (1 mL) was added in it and the slurry was
stirred at r.t. for 10 min followed by further irradiation of 2-3 min (100 °C, 60 W).
Amines or alcohol (1.0 equiv.) and CMPA (1.3 equiv.) was then added in it and
irradiated further under microwave (5 min, 60 °C, 100 W). The mixture was then cooled
and extracted with EtOAc (25 mL x 3). Column chromatography afforded pure
compound.
1
27. Representative physical data of the synthesized compounds: Compound 6c: H NMR
(300 MHz, CDCl3): δ = 2.74 (t, 2H, J = 7.2 Hz), 2.82 (s, 3H), 3.07-3.13 (m, 2H), 3.20 (t,
2H, J = 7.2 Hz), 3.70 (s, 3H), 4.87-4.90 (m, 1H), 6.10 (d, 1H, J = 7.5 Hz), 7.06(d, 2H, J
= 6.9 Hz), 7.12-7.25 (m, 3H), 7.42 (s, 1H), 7.56 (t, 1H, J = 7.2 Hz), 7.76-7.83(m, 2H),
7.90 (d, 1H, J = 8.4 Hz), 8.14 (d, 1H, J = 8.4 Hz), ppm; 13C NMR (75 MHz, CDCl3): δ =
21.12, 25.32, 35.22, 37.75, 53.12, 117.03, 120.51, 122.65, 123.61, 127.14, 127.33,
128.60, 129.10, 130.58, 135.65, 141.08, 146.86, 149.31, 159.24, 171.32, 171.90 ppm;
HRMS (ESI): m/z calcd. for C25H25N5O3 [M + Na]+: 466.1855; found: 466.1862.

OH
OH
OH
H
O
N
Y
Ar
O
HO
HO
Sugar/cyclic-linear
aliphatic
HO
H
Triazole
R
n
N
HO
N
N
OH
N
O
X
N
O
O
N
N
b
n
c
a
Our modified scaffold
Ar
n = 1, 2
FimH anagonists
Glycogen phosphorylase
inhibitor
(n = 2, 7; X = H, O; Y = C, N; R = Sugar, amino acid, aryl)
Figure 1. Carbohydrate linked triazole and triazolyl N-carboxamides.
R1
R1
X
N3
a)
HOOC
R2-NH2 or
N
N
N
TMSN3
Cu(I)
n
O
N
N
HOOC
R2
Basic alumina
R2-OH
CMPA
R1
X = Br, I
N
R1
X
n
n
R3
R3
HOOC
R2-NH2 or
b)
N
O
N
TMSN3
n
N
R3
X
N
R3
N3
R2
N
R2-OH
CMPA
X
HOOC
N
Cu(I)
Basic alumina
n
n
R3 = Sugar or alkyl
X = Br
Scheme 1. Four-component one-pot synthesis of triazolyl-N-carboxamides under microwave
irradiation.
CuCl
CuCl
Cu-X
1a
N
N
N
X = I
1b X = Br
N
N
1d
CH3
1c
N
N
N
N
N
Cu
Cu
S
S
Cu
S
Cu
Ph3P
Br
1g
1e
1f
1h
Figure 2. Copper catalysts used in the study.

Ph
OAc
O
OAc
O
O
N
MeO2C
N
NH
N
NH
AcO
AcO
N
N
N
OAc
OAc
N
O
N
N
AcO
AcO
MeO2C
Ph
NH
NH
N
N
N
O
O
7
8
Figure 3. Synthesis of bidentate1,4-disubstituted triazolyl N-carboxamides.

Table(s)
Table 1: Optimization of catalyst towards the synthesis of azido benzene from iodobenzene
and TMSN3 using various solid-supports
Entrya Solid support
Catalyst used Catalyst (mol %) Time (min) Yieldb (%)
A. Without additional base
1
TiO2
10
15
20
15
15
15
15
15
15
15
15
15
8
20
24
24
32
52
40
47
53
64
68
72
88
1a
1a
1a
1a
1a
1b
1c
1d
1e
1f
2
TiO2
10
10
10
10
10
10
10
10
10
10
10
3
TiO2
4
MgO
5
Basic alumina
Basic alumina
Basic alumina
Basic alumina
Basic alumina
Basic alumina
Basic alumina
Basic alumina
6
7
8
9
10
11
12
1g
1h
B. With Et3N as additional base
13 Basic alumina
C. With DBU as additional base
14 Basic alumina
15
10
88
1h
15
10
86
1h
aAll reactions were performed using iodobenzene (1.0 equiv.) and TMSN3 (1.1 equiv.) under
microwave irradiation (100 W, 70 C). Solid support (500 mg-1 gm) was used in each case.
bIsolated yield

Table 2: Synthesis of versatile 1,4-disubstituted triazolyl-N-carboxamidesa
Entry
Halide
Azide
Alkyne
Amine/Alcohol
Product (% Yield)b
I
OAc
O
O2N
OAc
HOOC
NO2
AcO
AcO
N
TMSN3
NH2
OAc
O
H
1
O
4a
N
AcO
AcO
N
3a
N
OAc
5a
5a
5a
O
2a
6a (81%)
Br
NO2
2
3
6a (66%)
3a
4a
4a
2b
NaN3
3b
6a (31%)
2a
I
N
H
N
4
5
3a
3a
4a
4a
N
N
MeO2C
NH2
2c
O
MeO2C
5b
6b (77%)
N
I
N
5b
H
N
N
CH3
N
N
2d
O
MeO2C
6c (86%)
CO2H
O2N
H
N
H
H
N
NH2
N
N
6
7
2a
2c
3a
3a
N
O
5c
N
O
O
6d (74%)
4b
4b
H
H
5c
N
N
N
N
N
O
O
6e (79%)
N
H3C
COOH
H
N
PhCH2OH
N
N
N
8
2d
H
N
O
BnO
5d
4c
O
O
6f (73%)
aReactions were performed using organic halide (1.0 equiv.), TMSN3 (1.1 equiv.), 1h (15
mol%), terminal alkynes (1.1 equiv.), organic amines or alcohols (1.0 equiv.), CPMA (1.3
equiv.) and basic alumina (500 mg-1 gm), under microwave irradiation. Products were
characterized by spectroscopic and analytical techniques.
bYield of the isolated pure product; some losses during purification is unavoidable in certain
cases.

Table 3. Synthesis of versatile 1,4-disubstituted triazolyl-N-carboxamidesa
Amine/Alcoh
Entry
Halide
Azide
Alkyne
Product (% Yield)b
ol
OAc
OAc
O
Br
OAc
OAc
OAc
O
AcO
OAc
OAc
1
3a
4a
N
OAc
5a
O
H
N
AcO
AcO
N
N
OAc
2e
O
6g (70%)
OAc
OAc
O
OAc
OAc
H
2
3
2e
2e
3a
3a
4b
4c
5c
H
N
N
N
N
N
O
O
6h (72%)
AcO
OAc
OAc
AcO
O
N
N
N
5d
H
BnO
N
O
O
6i (65%)
Br
OAc
N
4
3a
4a
5a
O
H
N
N
AcO
AcO
N
OAc
O
2f
6j (67%)
aReactions were performed using organic halide (1.0 equiv.), TMSN3 (1.1 equiv.), 1h (15
mol%), terminal alkynes (1.1 equiv.), organic amines or alcohols (1.0 equiv.), CMPA (1.3
equiv.) and basic alumina (500 mg - 1 gm), under microwave irradiation. Products were
characterized by spectroscopic and analytical techniques.
bYield of the isolated pure product; some losses during purification is unavoidable in certain
cases.

*Revised Manuscript
Graphical Abstract
Efficient synthesis of 1,4-disubstituted triazolyl N-carboxamides via a
simple and convenient MCR using basic alumina as solid support
Rammyani Pal, Swarbhanu Sarkar, Nivedita Chatterjee, Asish Kumar Sen*