Synthesis of new potential bis-intercalators based on chiral pyridine-2,6-dicarboxamides

Article abstract of DOI:10.1135/cccc19990288

Potential bis-intercalating compounds N,N-dibenzylidene-N²,N²′-(pyridine-2,6-dicarbonyl)-d i(aminoacidhydrazides) 4a-4j, N,N′-substituted pyridine-2,6-bis(carbohydrazides) 5a-5d and N,N′-substituted N²N²′-bis(pyridine-2,6-dicarbonyl)di(aminoacidhydraz ides) 6a-6g, both racemic and optically active, can be easily synthesized from pyridine-2,6-bis(carbohydrazide), natural amino acids and aromatic aldehydes or anhydrides of aromatic ortho-dicarboxylic acids.

Full text of DOI:10.1135/cccc19990288

288
Amr, Abd El-Salam, Attia, Stibor:
SYNTHESIS OF NEW POTENTIAL BIS-INTERCALATORS
BASED ON CHIRAL PYRIDINE-2,6-DICARBOXAMIDES
a
a
a1
Abd El-Galil AMR , Osama I. ABD EL-SALAM , Abd El-Hamid ATTIA
b,
and Ivan STIBOR *
a
Department of Organic Chemistry, National Research Centre, Dokki, Cairo-12622, Egypt;
e-mail: aattia@nrc.sci.eg
Department of Organic Chemistry, Prague Institute of Chemical Technology, 166 28 Prague 6,
Czech Republic; e-mail: ivan.stibor@vscht.cz
1
b
Received March 23, 1998
Accepted Jan uary 11, 1999
Dedicated to the memory of Dr Miroslav Protiva.
Poten tial bis-in tercalatin g com poun ds N,N-diben zyliden e-N2,N2′-(pyridin e-2,6-dicarbon yl)-
di(am in oacidh ydrazides) 4a–4j, N,N′-substituted pyridin e-2,6-bis(carboh ydrazides) 5a–5d an d
N,N′-substituted N2N2′-bis(pyridin e-2,6-dicarbon yl)di(am in oacidh ydrazides) 6a –6g, both
racem ic an d optically active, can be easily syn th esized from pyridin e-2,6-bis(carboh ydr-
azide), n atural am in o acids an d arom atic aldeh ydes or an h ydrides of arom atic orth o-dicar-
boxylic acids.
Key words: DNA in tercalation ; Ch iral in tercalators; Pyridin e-2,6-dicarboxam ides; Am in o acids;
Naph th alim ides; An tim icrobial activity.
Th e con cept of in tercalation was first in troduced by Lerm an 1 to explain th e
reversible n on covalen t bin din g of com poun ds with exten ded arom atic
(m ost often h eteroarom atic) m oieties to double-h elical DNA. Th e essen ce of
in tercalation is th e in sertion of such an alm ost plan ar m oiety between adja-
cen t base pairs of DNA, th ereby exten din g an d stabilizin g th e double h elix;
th e base-pair separation at an in tercalation site th us in creases2–8. Wh ereas
in itial studies focused on m olecules with a sin gle in tercalatin g m oiety9,10
,
th eir prom isin g an titum or activity11,12 an d/or sequen ce specificity13,14 h as
led research ers to in vestigate com poun ds th at con tain m ore th an on e in ter-
calatin g group15,16. Th e fam ily of in tercalatin g an titum or drugs com prises
also n aph th alim ides17. For som e of th em , th e an titum or activity h as been
proved, several of th em are n ow in ph ase I of clin ical developm en t18–20. It
h as been also kn own for a lon g tim e th at com bin ation of in trcalatin g un it
with am in o acid is prom isin g21. Moreover th ere are peptide m otifs occur-
Collect. Czech. Chem. Commun. (Vol. 64) (1999)

New Potential Bis-Intercalators
289
O
O
O
O
N
N
R
H
NH
X
HN
X
X
X
R
H
X = OCH
X = Cl
1a,
1b,
1c,
3
O
O
X = NHNH
2
CH
CH
CH
2
3
2
R
iPr
H
CH
X
3
HO
OCH
3
2a
3a
2b
3b
2c
3c
2d
3d
2e
3e
NHNH
2
O
O
N
R
H
NH
HN
R
H
O
NH
N
NH
N
O
CH
HC
Ar
Ar
CH
CH
CH
2
3
2
R
iPr
4c
4d
H
CH
Ar
3
HO
4a
4b
4e
4f
4g
4i
4j
4h
Cl
O
O
O
O
N
O
Y =
N
N
N
O
Y
O
Y
N
N
NH
HN
O
O
O
5a
5b
5c
5d
Collect. Czech. Chem. Commun. (Vol. 64) (1999)

290
Amr, Abd El-Salam, Attia, Stibor:
O
O
N
R
H
NH
HN
R
H
O
NH
Y
HN
Y
O
O
O
O
N
N
N
R = H,
Y =
N
O
O
O
6a
6b
6c
O
CH
CH
3
3
CH
2
3
CH
2
Y =
N
O
R =
CH
3
CH
HO
6d
6e
6f
6g
rin g repeateadly in carboxy-term in al dom ain of RNA polym erase II in m am -
m als22 wh ich are believed to be respon sible for th e ability of th is en zym e to
bin d to DNA by bis-in tercalation 23,24. Th e structure, con form ation an d
bin din g ability of th is peptide h ave been studied25, its syn th etic an alogues
were prepared an d th eir ability to bin d to DNA fragm en ts were studied26,27
.
It was proved th at th e peptide adopt β-turn con form ation en forced by sev-
eral h ydrogen bon ds th us directin g both flat un its at th e en ds of th e pep-
tide to be perpen dicular with distan ce about 700 pm wh ich is in good
correspon den ce with th e spatial requirem en ts for bis-in tercalation . On th e
oth er h an d, it is also kn own an d very recen tly proved by X-ray crystallogra-
ph y, th at peptides derived from pyridin e-2,6-dicarboxylic acid an d n atural
am in o acids adopts spon tan eously relatively rigid con form ation rein forced
by bi furcated h ydrogen bon din g between NH of carboxam ides in position
2 an d 6 of pyridin e n ucleus an d its n itrogen 28. Th is fin din g m akes th is
structure very prom isin g also from th e viewpoin t of bis-in tercalation . Con -
sequen tly, we h ave decided to study th e possibility of usin g th is con -
form ation ally restricted structure as a scaffold for attach m en t of arom atic
m oieties. In th e first stage we h ave decided to use both acylh ydrazon es an d
im ides as flat un its.
Collect. Czech. Chem. Commun. (Vol. 64) (1999)

New Potential Bis-Intercalators
291
In th is com m un ication , we report on facile syn th esis of n ew type of po-
ten tial bis-in tercalatin g com poun ds 5 an d 6. Th e syn th etic procedures are
very sim ple, easily perform ed on m ultigram scale. Products are stable, crys-
tallin e com poun ds, an y racem ization h as n ot been observed.
Th e syn th esis starts from dim eth yl pyridin e-2,6-dicarboxylate (1a) or cor-
respon din g dich loride29,30 (1b). Dih ydrazide 1c was prepared accordin g to
th e literature31. Diesters 2a–2e were prepared from acid ch loride 1b an d es-
ter of appropriate am in o acid followin g th e stan dard acylation procedure.
Th ey were used as startin g m aterials for th e syn th esis of dih ydrazides 3a–3e
usin g h ydrazin olysis. Straigh tforward reaction of h ydrazides 3a–3e with se-
lected com m ercial aldeh ydes h as furn ish ed 4a–4j. Th e reaction of
h ydrazides 1c an d 3a–3e with dicarboxan h ydrides h as furn ish ed target im -
ides, 5a–5d an d 6a–6g, respectively. Prelim in ary biological activity screen -
in g of selected com poun ds h as been perform ed again st m icroorgan ism s
represen tin g Gram -positive, Gram -n egative bacteria, yeast, an d fun gi, usin g
th e bioassay tech n ique of an tibiotics specified in US Ph arm acopoeia at
50 γ/m l. Am picillin an d ch loram ph en icol were used as stan dards. Th e re-
sults obtain ed are sum m arized in Table I.
TABLE I
Results of an tibiotics bioassay (US Ph arm acopoeia, 50 γ/m l)
Bacillus
subtilis
Escherichia
coli
Staphylococcus
aureus
Candida
albicans
Aspergillus
niger
Com poun d
+
+
+
–
+
Am picillin
Ch loram ph en icol
+
–
–
–
–
–
–
+
–
+
+
+
+
–
–
–
–
–
–
+
–
+
–
+
+
–
–
–
–
–
–
–
–
–
–
–
–
–
–
+
–
–
–
–
–
+
+
–
+
+
+
–
+
+
+
–
+
–
+
–
2a
2b
3e
4a
4g
6b
6c
6d
6e
6f
6g
Collect. Czech. Chem. Commun. (Vol. 64) (1999)

292
Amr, Abd El-Salam, Attia, Stibor:
Selected Sch iff bases 4 as well as im ides 5 an d 6 are n ow un der study with
respect to th eir ability to in tercalate in to DNA fragm en ts.
EXPERIMENTAL
Meltin g poin ts are un corrected, th e syn th esized com poun ds were dried in vacuo for 8 h (or
overn igh t), solven ts were evaporated on rotary evaporator at 40 °C. NMR spectra (δ, ppm ; J,
Hz) with TMS as in tern al stan dard were recorded on a Varian Gem in i 300 HC spectrom eter
in CDCl3 at 25 °C. MS spectra (FAB) were m easured on a ZAB-EQ (VG An alytical) usin g Xe
atom bom bardem en t an d Fin igan SPQ-7000, GC-MS spectrom eter. Optical rotation s were
m easured on an Atago Polax-D polarim eter at 30 °C an d are given in deg cm 3 g–1 dm –1
.
An tim icrobial activity screen in g h ave been perform ed by Prof. El-Diwan y, Departm en t of
Natural an d Microbial Product, Nation al Research Cen ter, Cairo, Egypt.
Diesters 2a–2e. Gen eral Procedure
To a solution of am in o acid m eth yl ester (2 m m ol), obtain ed by addition of trieth ylam in e
(2 m m ol) to am in o acid (2 m m ol) m eth yl ester h ydroch loride in 50 m l of dry dich loro-
m eth an e at –15 °C followed by 15 m in stirrin g, pyridin e-2,6-bis(carbon yl ch loride) (1b)
(1 m m ol) in 15 m l of dry dich lorom eth an e was added dropwise at –15 °C followed by
trieth ylam in e (2 m m ol) in order to keep th e reaction m ixture sligh tly alkalin e (pH 8). Th e
reaction m ixture was stirred at –15 °C for 3 h , at am bien t tem perature for 12 h , th en
wash ed with water (2 × 50 m l), 1 M h ydroch loric acid (2 × 50 m l), saturated sodium
h ydrogen carbon ate (2 × 50 m l) an d fin ely with water, dried over Na2SO4, evaporated an d
purified by crystallization .
Dimethyl N,N′-(pyridine-2,6-dicarbonyl)diglycinate (2a) was obtain ed in 45% yield. M.p.
135–140 °C (eth an ol–petroleum eth er). For C13H15N3O6 (309.3) calculated: 50.48% C,
4.88% H, 13.58% N; foun d: 50.36% C, 5.08% H, 13.48% N. 1H NMR: 8.70–8.6 t, 2 H (NH);
8.2–8.1 d, 2 H (3 H-pyridin e); 7.95–7.85 t, 1 H (4 H-pyridin e); 4.2 d, 4 H (2 × CH2); 3.75 s,
6 H (2 × CH3). 13C NMR: 41.49, 52.72, 125.35, 139.28, 148.23, 164.33, 171.23. Mass spec-
trum (M+, m/z (rel. %)): 309 (72).
Dimethyl N,N′-(pyridine-2,6-dicarbonyl)di((S)-valinate) (2b) was obtain ed in 56% yield as oil.
For C19H27N3O6 (393.4) calculated: 57.99% C, 6.92% H, 10.68% N; foun d: 57.85% C,
6.89% H, 10.63% N; [α]D –20 (eth an ol). 1H NMR: 8.4–8.3 d, 2 H (NH); 8.3–8.2 d, 2 H
(3 H-pyridin e); 8.1–8.0 t, 1 H (4 H-pyridin e); 4.8–4.65 t, 2 H (2 × CHN); 3.75 s, 6 H (2 ×
OCH3), 2.4–2.2 m , 2 H (2 × CHC); 1.1–1.0 d, 12 H (4 × CH3). 13C NMR: 17.14, 18.53, 30.94,
51.67, 56.92, 124.72, 138.93, 147.95, 162.69, 171.32. Mass spectrum (M+, m/z (rel. %)): 393
(51).
Dimethyl N,N′-(pyridine-2,6-dicarbonyl)di((S)-leucinate) (2c) was obtain ed in 51% yield. M.p.
130–132 °C (eth an ol–petroleum eth er). For C21H31N3O6 (421.5) calculated: 59.84% C,
7.41% H, 9.96% N; foun d: 59.63% C, 7.70% H, 9.90% N; [α]D –10 (eth an ol). 1H NMR:
8.4–8.3 d, 2 H (NH); 8.2 d, 2 H (3 H-pyridin e); 8.1–8.0 t, 1 H (4 H-pyridin e); 4.9–4.8 q, 2 H
(2 × CHN); 3.75 s, 6 H (2 × OCH3), 1.9–1.7 m , 2 H (2 × CH2); 1.3–1.2 m , 2 H (2 × CHC);
1.1–0.9 d, 12 H (4 × CH3). 13C NMR: 22.52, 23.31, 25.53, 42.13, 51.57, 52.89, 125.77,
139.55, 148.89, 163.62, 173.71. Mass spectrum (M+, m/z (rel. %)): 422 (100).
Dimethyl N,N′-(pyridine-2,6-dicarbonyl)di((S)-phenylalaninate) (2d ) was obtain ed in 80%
yield. M.p. 122–125 °C (eth an ol–petroleum eth er). For C27H27N3O6 (489.5) calculated:
Collect. Czech. Chem. Commun. (Vol. 64) (1999)

New Potential Bis-Intercalators
293
66.24% C, 5.55% H, 8.58% N; foun d: 65.93% C, 5.61% H, 8.48% N; [α]D –55 (eth an ol).
1H NMR: 8.4–8.3 d, 2 H (NH); 8.1–7.9 m , 3 H (pyridin e); 7.4–7.1 m , 10 H (2 × Ph );
5.1–5.0 q, 2 H (2 × CHN); 3.8 s, 6 H (2 × OCH3); 3.4–3.1 m , 4 H (2 × CH2Ph ). 13C NMR:
38.30, 52.67, 53.93, 125.64, 127.48, 129.01, 129.53, 136.20, 139.29, 148.60, 163.32, 171.91.
Mass spectrum (M+, m/z (rel. %)): 489 (41).
Dimethyl N,N′-(pyridine-2,6-dicarbonyl)di((S)-tyrosinate) (2e) was obtain ed in 40% yield. M.p.
122–125 °C (eth an ol–petroleum eth er). For C27H27N3O6 (521.5) calculated: 62.18% C,
5.21% H, 8.05% N; foun d: 62.20% C, 5.35% H, 7.90% N; [α]D –100 (DMF). 1H NMR: 10.3 s,
2 H (2 × OH); 9.2–8.8 d, 2 H (NH); 8.3–8.1 m , 3 H (pyridin e); 7.5–6.8 m , 8 H (2 × Ph );
4.6–4.5 t, 2 H (2 × CHN); 3.6–3.5 m , 4 H (2 × CH2Ph ); 3.2–3.0 s, 6 H (2 × OCH3). 13C NMR:
36.71, 52.98, 54.24, 122.28, 126.02, 130.84, 134.87, 139.54, 148.69, 156.19, 163.61, 172.55.
Mass spectrum (M+, m/z (rel. %)): 522 (20).
Dih ydrazides 3a–3e. Gen eral Procedure
Hydrazin e h ydrate (16 m m ol, 80% aqueous solution ) was added to a diester 2 (1 m m ol) in
m eth an ol (50 m l), refluxed for 5 h , evaporated, triturated with ligh t petroleum an d purified
by crystallization .
N2,N2′-(pyridine-2,6-dicarbonyl)di(glycinehydrazide) (3a) was obtain ed in 80% yield. M.p.
228–230 °C (DMF–water). For C11H15N7O4 (309.3) calculated: 42.71% C, 4.88% H,
31.70% N; foun d: 42.68% C, 4.74% H, 31.45% N. 1H NMR: 9.70–9.55 t, 2 H (2 × NH2-NH);
9.20–9.10 t, 2 H (2 × NH); 8.2–8.1 m , 3 H (pyridin e); 4.3–4.2 s, 4 H (2 × CH2); 4.0–3.90 s,
4 H (2 × NH2). 13C NMR: 41.02, 124.24, 139.34, 148.42, 163.58, 168.13. Mass spectrum (M+,
m/z (rel. %)): 309 (72).
N2,N2′-(pyridine-2,6-dicarbonyl)di((S)valinehydrazide) (3b) was obtain ed in 79% yield. M.p.
125–128 °C (dioxan e–ben zen e). For C17H27N7O4 (393.45) calculated: 51.89% C, 6.91% H,
24.98% N; foun d: 51.97% C, 6.68% H, 24.89% N; [α]D –145 (DMF). 1H NMR: 9.50–9.30 d,
2 H (2 × NH2-NH); 8.75–8.65 d, 2 H (2 × NH); 8.30–8.10 m , 3 H (pyridin e); 4.35–4.20 t, 2 H
(2 × N-CH); 4.20–3.50 bs, 4 H (2 × NH2); 2.20–2.05 m , 2 H (2 × C-CH); 1.00–0.80 m , 12 H
(4 × CH3). 13C NMR: 18.82, 19.62, 31.17, 57.57, 125.19, 140.09, 149.04, 163.37, 170.37.
Mass spectrum (M+, m/z (rel. %)): 394 (2).
N2,N2′-(pyridine-2,6-dicarbonyl)di((S)leucinehydrazide) (3c) was obtain ed in 85% yield. M.p.
110–113 °C (eth an ol–water). For C19H31N7O4 (421.5) calcu lated: 54.14% C, 7.41% H,
23.26% N; foun d: 53.99% C, 7.25% H, 23.15% N; [α]D +40 (DMF). 1H NMR: 9.50–9.30 s, 2 H
(2 × NH2-NH ); 9.10–9.00 d, 2 H (2 × NH); 8.30–8.10 m , 3 H (pyridin e); 4.65–4.45 t, 2 H
(2 × N-CH); 4.40–3.80 bs, 4 H (2 × NH2); 1.90–1.70 m , 2 H (2 × C-CH); 1.70–1.50 t, 4 H
(4 × CH2); 1.00–0.80 m , 12 H (4 × CH3). 13C NMR: 22.22, 23.24, 24.90, 40.13, 51.04, 125.14,
139.67, 149.24, 163.58, 171.35. Mass spectrum (M+, m/z (rel. %)): 422 (8).
N2,N2′-(pyridine-2,6-dicarbonyl)di((S)phenylalaninehydrazide) (3d ) was obtain ed in 83% yield.
M.p. 197–200 °C (eth an ol–dieth yl eth er). For C25H27N7O4 (489.5) calculated: 61.33% C,
5.55% H, 20.02% N; foun d: 61.26% C, 5.53% H, 20.18% N; [α]D –100 (DMF). 1H NMR: 9.50 s,
2 H (2 × NH2-NH); 9.20–9.10 d, 2 H (2 × NH); 8.20–8.00 m , 3 H (pyridin e); 7.50–7.10 m , 10 H
(2 × Ph ); 4.70–4.60 s, 2 H (2 × N-CH); 4.50–3.80 bs, 4 H (2 × NH2); 2.50 d, 4 H (2 × CH2).
13C NMR: 37.72, 53.66, 124.63, 126.33, 128.26, 137.81, 139.23, 148.61, 163.05, 169.87. Mass
spectrum (M+, m/z (rel. %)): 490 (10).
N2,N2′-(pyridine-2,6-dicarbonyl)di((S)tyrosinehydrazide) (3e) was obtain ed in 71% yield. M.p.
225–228 °C (m eth an ol–water). For C25H27N7O6 (521.5) calculated: 57.57% C, 5.21% H,
Collect. Czech. Chem. Commun. (Vol. 64) (1999)

294
Amr, Abd El-Salam, Attia, Stibor:
18.80% N; foun d: 57.49% C, 5.23% H, 18.74% N; [α]D –110 (DMF). 1H NMR: 10.65–10.50 s,
2 H (2 × OH); 9.40–9.30 s, 2 H (2 × NH2-NH); 9.20–9.00 d, 2 H (2 × NH); 8.20–8.00 m , 3 H
(pyridin e); 7.30–7.10 s, 4 H (Ph ); 6.80–6.60 s, 4 H (Ph ); 4.70–4.50 s, 2 H (2 × N-CH);
4.30–4.10 s, 4 H (2 × NH2); 3.10–2.95 d, 4 H (2 × CH2). 13C NMR: 37.38, 54.22, 115.45,
124.04, 124.98, 128.13, 139.61, 148.98, 156.09, 163.32, 170.35.
Dih ydrazon es 4a–4j. Gen eral Procedure
A solution of a dih ydrazide 3a–3e (1 m m ol) an d an arom atic aldeh yde (2 m m ol) in 100 m l
of absolute m eth an ol was refluxed for 6 h . Th e reaction m ixture was cooled an d m ost of th e
solven t was evaporated. Th e crystallin e crude product was collected by filtration , wash ed
with eth er an d purified by crystallization .
N,N′-Dibenzylidene-N2,N2′-(pyridine-2,6-dicarbonyl)di(glycinehydrazide) (4a) was obtain ed in
42% yield. M.p. 297–300 °C (DMF–water). For C25H23N7O4 (485.5) calculated: 61.84% C,
4.77% H, 20.19% N; found: 61.79% C, 4.88% H, 20.14% N. 1H NMR: 9.90–9.80 t, 2 H (2 × N-NH);
9.80–9.60 s, 2 H (2 × NH); 8.35–8.05 m , 3 H (pyridin e); 7.75–7.45 m , 10 H (2 × Ph ); 4.60 s, 2 H
(2 × N=CH); 4.10 s, 4 H (2 × CH2). 13C NMR: 41.79, 124.47, 127.10, 128.85, 130.07, 134.24,
139.58, 143.72, 147.52, 163.84, 165.48, 170.18. Mass spectrum (M+, m/z (rel. %)): 486 (35).
N,N′-Bis(4-chlorobenzylidene)-N2,N2′-(pyridine-2,6-dicarbonyl)di(glycinehydrazide) (4b) was ob-
tain ed in 86% yield. M.p. 328–330 °C (DMF–water). For C25H21Cl2N7O4 (554.4) calculated:
54.16% C, 3.81% H, 17.68% N; foun d: 54.10% C, 3.82% H, 17.54% N. 1H NMR: 9.90–9.60 s,
4 H (4 × NH); 8.25–8.05 m , 3 H (pyridin e); 7.80–7.55 m , 8 H (2 × Ph ); 4.80–4.60 s, 2 H (2 ×
N=CH); 4.10 s, 4 H (2 × CH2). 13C NMR: 41.13, 124.40, 128.45, 128.85, 132.97, 134.30,
139.52, 143.62, 145.62, 148.42, 163.64, 165.40, 170.16. Mass spectrum (M+, m/z (rel. %)):
554 (10).
N,N′-Dibenzylidene-N2,N2′-(pyridine-2,6-dicarbonyl)di((S)valinehydrazide) (4c) was obtain ed in
61% yield. M.p. 120–122 °C (eth an ol–water). For C31H35N7O4 (596.7) calculated: 65.36% C,
6.19% H, 17.21% N; foun d: 65.28% C, 6.14% H, 17.12% N; [α]D +10 (DMF). 1H NMR: 9.35 s,
2 H (2 × N-NH); 8.65 d, 2 H (2 × C-NH); 8.40–8.05 m, 3 H (pyridine); 7.80–7.30 m, 10 H (2 × Ph);
5.40 s, 2 H (2 × N=CH); 4.40–4.20 t, 2 H (2 × CH-N); 2.25–2.05 m , 2 H (2 × CH(CH3)2); 1.00 t,
6 H (2 × CH3); 0.80 t, 6 H (2 × CH3). 13C NMR: 18.35, 19.09, 30.54, 57.05, 124.39, 127.27,
128.67, 130.26, 133.89, 139.52, 147.46, 148.51, 163.24, 165.52, 172.24.
N,N′-Bis(4-chlorobenzylidene)-N2,N2′-(pyridine-2,6-dicarbonyl)di((S)valinehydrazide) (4d ) was
obtain ed in 54% yield. M.p. 208–210 °C (DMF–water). For C31H33Cl2N7O4 (638.6) calculated:
58.30% C, 5.20% H, 15.35% N; foun d: 58.41% C, 5.18% H, 15.29% N; [α]D +150 (DMF).
1H NMR: 9.23 s, 2 H (2 × N-NH); 8.45 d, 2 H (2 × C-NH); 8.40–8.10 m , 3 H (pyridin e);
7.80–7.30 m , 8
H (2 × Ph ); 5.20 s, 2 H (2 × N=CH); 4.45–4.24 t, 2 H (2 × CH-N);
2.30–2.15 m , 2 H (2 × CH(CH3)2); 1.05 t, 6 H (2 × CH3); 0.85 t, 6 H (2 × CH3). 13C NMR:
18.92, 19.45, 30.75, 58.36, 125.08, 128.61, 129.01, 134.60, 134.77, 139.92, 146.23, 148.86,
163.21, 167.64, 172.54.
N,N′-Dibenzylidene-N2,N2′-(pyridine-2,6-dicarbonyl)di((S)leucinehydrazide) (4e) was obtain ed
in 60% yield. M.p. 176–179 °C (eth an ol–petroleum eth er). For C33H39N7O4 (597.7) calcu-
lated: 66.30% C, 6.58% H, 16.41% N; foun d: 66.18% C, 6.46% H, 16.36% N. 1H NMR:
9.65 s, 2 H (2 × N-NH); 8.76 d, 2 H (2 × C-NH); 8.45–8.15 m , 3 H (pyridin e); 7.90–7.35 m ,
10 H (2 × Ph ); 4.80 s, 2 H (2 × N=CH); 4.38–4.18 m , 2 H (2 × CH-N); 3.50 t, 4 H (2 × CH2);
2.27–2.15 m , 2 H (2 × CH(CH3)2); 1.10 t, 6 H (2 × CH3); 0.90 t, 6 H (2 × CH3). 13C NMR:
Collect. Czech. Chem. Commun. (Vol. 64) (1999)

New Potential Bis-Intercalators
295
21.57, 22.72, 24.66, 41.52, 51.33, 124.65, 127.01, 129.14, 133.49, 134.37, 139.19, 145.70,
148.69, 163.21, 168.31, 173.26.
N,N′-Bis(4-chlorobenzylidene)-N2,N2′-(pyridine-2,6-dicarbonyl)di((S)leucinehydrazide) (4f) was
obtain ed in 67% yield. M.p. 123–125 °C (eth an ol). For C33H37Cl2N7O4 (666.6) calculated:
59.45% C, 5.59% H, 14.70% N; foun d: 59.23% C, 5.68% H, 14.59% N; [α]D +80 (DMF).
1H NMR: 9.40 s, 2 H (2 × N-NH); 9.20–9.10 t, 2 H (2 × C-NH); 8.30–8.10 m , 3 H (pyridin e);
7.70–7.40 m , 8 H (2 × Ph); 5.50 s, 2 H (2 × N=CH); 4.70 t, 2 H (2 × CH-C); 3.40 d, 4 H (2 × CH2);
2.00–1.70 m , 2 H (2 × CH(CH3)2); 1.10 t, 6 H (2 × CH3); 0.90 t, 6 H (2 × CH3). Mass spec-
trum (FAB, glycerol–th ioglycerol–DMSO) (M+, m/z (rel. %)): 666 (M + H, 100).
N,N′-Dibenzylidene-N2,N2′-(pyridine-2,6-dicarbonyl)di((S)phenylalaninehydrazide) (4g) was ob-
tain ed in 60% yield. M.p. 145–147 °C (m eth an ol–water). For C39H35N7O4 (665.8) calculated:
70.36% C, 5.29% H, 14.72% N; foun d: 70.58% C, 5.33% H, 14.42% N; [α]D +150 (DMF).
1H NMR: 9.40 s, 2 H (2 × N-NH); 8.85 s, 2 H (2 × C-NH); 8.40–8.10 m , 3 H (pyridin e);
7.90–7.15 m, 20 H (2 × Ph); 4.90 s, 2 H (2 × N=CH); 4.50 t, 2 H (2 × CH-N); 3.50 t, 4 H (2 × CH2).
13C NMR: 40.25, 51.33, 124.45, 126.54, 128.09, 128.37, 128.52, 128.75, 133.03, 134.27,
134.37, 139.19, 145.70, 148.69, 163.21, 168.31, 173.26.
N,N′-Bis(4-chlorobenzylidene)-N2,N2′-(pyridine-2,6-dicarbonyl)di((S)phenylalaninehydrazide)
(4h ) was obtain ed in 55% yield. M.p. 215–220 °C (m eth an ol–water). For C39H33Cl2N7O4
(734.6) calculated: 63.76% C, 4.52% H, 13.34% N; foun d: 63.86% C, 4.47% H, 13.55% N;
[α]D +70 (DMF). 13C NMR: 41.25, 51.44, 125.20, 127.27, 127.52, 128.78, 129.82, 130.52,
131.75, 134.24, 134.56, 139.81, 147.85, 148.98, 163.85, 167.73, 172.59. Mass spectrum (M+,
m/z (rel. %)): 734 (80).
N,N′-Dibenzylidene-N2,N2′-(pyridine-2,6-dicarbonyl)di((S)tyrosinehydrazide) (4i) was obtain ed
in 65% yield. M.p. 210–212 °C (m eth an ol–dieth yl eth er). For C39H35N7O6 (697.8) calculated:
67.13% C, 5.06% H, 14.05% N; foun d: 66.95% C, 5.12% H, 14.12% N; [α]D +70 (DMF).
13C NMR: 41.52, 53.23, 123.98, 127.65, 127.96, 128.25, 130.25, 134.75, 139.62, 146.21,
148.65, 153.95, 163.75, 165.39, 172.54. Mass spectrum (M+, m/z (rel. %)): 698 (3).
N,N′-Bis(4-chlorobenzylidene)-N2,N2′-(pyridine-2,6-dicarbonyl)di((S)tyrosinehydrazide) (4j) was
obtain ed in 58% yield. M.p. 178–180 °C (m eth an ol–water). For C39H33Cl2N7O6 (766.6) cal-
culated: 61.10% C, 4.34% H, 12.79% N; foun d: 60.85% C, 4.45% H, 12.82% N; [α]D –25
(DMF). 1H NMR: 11.50 s, 2 H (2 × OH); 9.40–9.30 d, 2 H (2 × N-NH); 8.70 s, 2 H (2 × C-NH);
8.90–8.30 m , 3 H (pyridin e); 7.70–7.60 d, 8 H (2 × Ph ); 7.20–7.10 m , 8 H (2 × Ph ); 5.75 s,
2 H (2 × N=CH); 4.75 t, 2 H (2 × CH-N); 3.40 d, 4 H (2 × CH2). 13C NMR: 42.05, 54.62,
124.32, 127.26, 127.89, 128.55, 129.65, 133.24, 134.39, 134.81, 139.26, 145.23, 147.96,
154.26, 163.65, 165.43, 171.95.
Bis-Diim ides 5a–5d an d 6a–6g. Gen eral Procedure
A m ixture of pyridin e-2,6-bis(carboh ydrazide) (1c, 3a–3e) (1 m m ol) an d an appropriate di-
carboxylic acid an h ydride (2 m m ol) was refluxed in 50 m l of glacial acetic acid for 6 h . Th e
reaction m ixture was evaporated, cooled an d th e crystallin e product was collected by filtra-
tion . Th e crude product was wash ed with cold acetic acid, dried an d purified by crystalliza-
tion to yield com poun ds 5a–5d an d 6a–6g.
N,N′-Disuccinylpyridine-2,6-bis(carbohydrazide) (5a) was prepared from 1c an d succin ic an -
h ydride in 68% yield. M.p. >350 °C (acetic acid–dieth yl eth er). For C15H13N5O6 (359.3) cal-
culated: 50.13% C, 3.65% H, 19.50% N; foun d: 50.32% C, 3.58% H, 19.41% N. 1H NMR:
(DMSO-d6): 11.50 bs, 2 H (NH); 8.34 s, 3 H (arom .); 2.93 bs, 8 H (COCH2). 13C NMR
Collect. Czech. Chem. Commun. (Vol. 64) (1999)

296
Amr, Abd El-Salam, Attia, Stibor:
(DMSO-d6): 26.44, 126.26, 140.58, 146.53, 161.24, 174.22. Mass spectrum (FAB, glycerol–
th ioglycerol–DMSO), m/z (rel. %): 360 (M + H, 70).
N,N′-Dimaleoylpyridine-2,6-bis(carbohydrazide) (5b) was prepared from 1c an d m aleic an h y-
dride in 90% yield. M.p. 305 °C (DMF–water). For C15H9N5O6 (355.3) calculated: 50.71% C,
2.55% H, 19.71% N; foun d: 50.68% C, 2.60% H, 19.85% N. 1H NMR (DMSO-d6): 11.24 bs,
2 H (NH); 8.27 s, 3 H (arom .); 6.47, 6.43, 6.37, 6.33 AB system , 4 H (4 × CH=). 13C NMR
(DMSO-d6): 125.41, 126.80, 133.18, 140.07, 147.66, 161.93, 163.47, 167.15. Mass spectrum ,
m/z (rel. %): 355 (18).
N,N′-Bis(pyridine-2,3-dicarbonyl)pyridine-2,6-bis(carbohydrazide) (5c) was prepared from 1c
an d pyridin e-2,3-dicarboxylic an h ydride in 82% yield. M.p. >300 °C (DMF–water). For
C
21H11N7O6 (457.4) calculated: 55.15% C, 2.42% H, 21.44% N; foun d: 55.25% C, 2.35% H,
21.17% N. 1H NMR (DMSO-d6): 11.99 bs, 2 H (NH); 9.14 d, 2 H, J = 4.4 (H-2 H-pyridin e);
8.52 d, 2 H, J = 7.7 (H-4 H-pyridin e); 8.39 s, 3 H (Ar-pyridin e); 7.96 dd, 2 H, J = 4.4, J = 7.7
(3 H-pyridin e). 13C NMR (DMSO-d6): 126.36, 127.17, 129.44, 132.84, 141.17, 146.89, 149.72,
156.52, 162.52, 164.15, 164.25.
N,N′-Bis(naphthalene-1,8-dicarbonyl)pyridine-2,6-bis(carbohydrazide) (5d ) was prepared from
1c an d n aph th alen e-1,8-dicarboxylic an h ydride in 72% yield. M.p. >300 °C (DMF). For
C
31H17N5O6 (555.5) calculated: 67.03% C, 3.08% H, 12.60% N; foun d: 66.70% C, 3.35% H,
12.50% N. 1H NMR (DMSO-d6): 11.99 bs, 2 H (NH); 8.62 m , 8 H (βH-n aph th alen e); 8.42 m ,
3 H (pyridin e); 7.97 m , 4 H (αH-n aph th alen e). Mass spectrum (FAB, glycerol–th ioglycerol–
DMSO), m/z (rel. %): 556.1 (M + H, 100).
N,N′-Dimaleolyl-N2,N2′-(pyridine-2,6-dicarbonyl)di(glycinehydrazide) (6a) was prepared from
3a an d m aleic an h ydride in 70% yield. M.p. >235–240 °C. For C19H15N7O8 (469.4) calcu-
lated: 48.62% C, 3.22% H, 20.89% N; foun d: 48.55% C, 3.14% H, 20.84% N. 1H NMR
(DMSO-d6): 11.37 bs, 2 H (NH); 9.71 bt, 2 H, J = 6 (NH-CH); 8.21 bs, 3 H (pyridin e); 6.33 m ,
4 H (CH=); 4.09 bd, 4 H, J = 6 (CH2NH). 13C NMR (DMSO-d6 ): 41.16, 125.24, 128.50,
133.34, 140.35, 149.22, 163.55, 164.52, 167.58, 168.18. Mass spectrum , m/z (rel. %): 469 (2).
N,N′-Bis(pyridine-2,3-dicarbonyl)-N2,N2′-(pyridine-2,6-dicarbonyl)di(glycinehydrazide) (6b) was
prepared from 3a an d pyridin e-2,3-dicarboxylic an h ydride in 60% yield. M.p. >300 °C
(DMF–water). For C25H17N9O8 (571.5) calculated: 52.543% C, 3.00% H, 22.06% N; foun d:
52.67% C, 3.05% H, 21.96% N. 1H NMR (DMSO-d6): 11.05 bs, 2 H (NH); 9.83 bt, 2 H, J = 6.1
(NH-CH); 9.07 d, 2 H, J = 4.9 (2 H-pyridin e); 8.41 d, 2 H, J = 7.7 (4 H-pyridin e); 8.25 m , 3 H
(pyridin e); 7.88 dd, 2 H, J = 4.9, J = 7.7 (3 H-pyridin e); 4.32 bd, 4 H (CH2NH). Mass spec-
trum (FAB, glycerol–th ioglycerol–DMSO), m/z (rel. %): 572.0 (M + H, 55).
N,N′-Bis(naphthalene-1,8-dicarbonyl)-N2,N2′-(pyridine-2,6-dicarbonyl)di(glycinehydrazide) (6c)
was prepared from 3a an d n aph th alen e-1,8-dicarboxylic an h ydride in 65% yield. M.p.
235–240 °C (dioxan e–ben zen e). For C35H23N7O8 (669.6) calculated: 62.78% C, 3.46% H,
14.64% N; foun d: 62.75% C, 3.42% H, 14.60% N. 1H NMR (DMSO-d6): 10.80 s, 2 H (2 ×
NH); 8.90–8.80 m , 2 H (2 × NH); 8.52–8.50 m , 8 H (βH-n aph th alen e); 8.10 m , 3 H
(pyridin e); 7.90–7.80 m , 4 H (αH-n aph th alen e); 3.58 d, 4 H (CH2NH). Mass spectrum , m/z
(rel. %): 669 (M+, 15).
N,N′-Bis(naphthalene-1,8-dicarbonyl)-N2,N2′-(pyridine-2,6-dicarbonyl)di((S)-valinehydrazide)
(6d ) was prepared from 3b an d n aph th alen e-1,8-dicarboxylic an h ydride in 65% yield. M.p.
>280 °C (DMF–water); [α]D +20 (acetic acid). For C41H35N7O8 (753.8) calculated: 65.32% C,
4.68% H, 13.01% N; foun d: 65.20% C, 4.52% H, 12.89% N. 1H NMR (DMSO-d6): 11.10 bs,
2 H (NH); 8.68 m , 2 H (NH-CH); 8.47 m , 8 H (βH-naphthalene); 8.24 m , 3 H (pyridine); 7.86 m ,
4 H (αH-n aph alen e); 4.76 m , 2 H (CHNH); 2.33 m , 2 H (CH(CH3)2); 1.08 d an d 1.02 d, 2 ×
Collect. Czech. Chem. Commun. (Vol. 64) (1999)

New Potential Bis-Intercalators
297
6 H, J = 7.1 (CH3). 13C NMR (DMSO-d6): 17.77, 19.13, 31.36, 56.38, 121.53, 125.04, 127.26,
131.46, 132.49, 135.10, 135.40, 140.00, 148.61, 161.51, 162.98, 169.44. Mass spectrum , m/z
(rel. %): 753 (M+, 10).
N,N′-Bis(naphthalene-1,8-dicarbonyl)-N2,N2′-bis(pyridine-2,6-dicarbonyl)di((S)-leucinehydrazide)
(6e) was prepared from 3c an d n aph th alen e-1,8-dicarboxylic an h ydride in 75% yield. M.p.
230–235 °C (dioxan e–ben zen e); [α]D –30 (acetic acid). For C43H39N7O8 (781.5) calculated:
66.06% C, 5.03% H, 12.54% N; foun d: 65.95% C, 4.89% H, 12.50% N. 1H NMR (DMSO-d6):
11.15 s, 2 H (2 × NH); 9.20–9.10 m , 2 H (2 × NH-CH); 8.60–8.52 m , 8 H (βH-n aph th alen e);
8.16–8.13 m , 3 H (pyridin e); 8.02–7.90 m , 4 H (αH-n aph th alen e); 4.80 m , 2 H (2 × CHNH);
3.75 t, 4 H (2 × CH2); 2.25 m , 2 H (2 × CH(CH3)2); 1.80 d, 12 H (4 × CH3). Mass spectrum ,
m/z (rel. %): 781 (M+, 12).
N,N′-Bis(naphthalene-1,8-dicarbonyl)-N2,N2′-bis(pyridine-2,6-dicarbonyl)di((S)-phenylalanine-
hydrazide) (6f) was prepared from 3d an d n aph th alen e-1,8-dicarboxylic an h ydride in 78%
yield. M.p. 186–188 °C (dioxan e–ben zen e); [α]D +40 (acetic acid). For C49H35N7O8 (849.7)
calculated: 69.25% C, 4.15% H, 11.54% N; foun d: 69.20% C, 4.10% H, 11.51% N. 1H NMR
(DMSO-d6): 11.28 s, 2 H (2 × NH); 9.31–9.21 m , 2 H (2 × NH-CH); 8.58–8.50 m , 8 H
(βH-n aph th alen e); 8.15–8.13 m , 3
H (pyridin e); 7.95–7.87 m , 4 H (αH-n aph th alen e);
7.49–7.19 m , 10 H (2 × Ph ); 5.19 t, 2 H (2 × CHNH); 3.56 d, 4 H (2 × CH2). Mass spectrum ,
m/z (rel. %): 849 (M+, 2).
N,N′-Bis(naphthalene-1,8-dicarbonyl)-N2,N2′-bis(pyridine-2,6-dicarbonyl)di((S)-tyrosinehydrazide)
(6g) was prepared from 3e an d n aph th alen e-1,8-dicarboxylic an h ydride in 75% yield. M.p.
208–210 °C (dioxan e–ben zen e); [α]D –50 (acetic acid). For C49H35N7O10 (881.7) calculated:
66.74% C, 4.00% H, 11.12% N; foun d: 66.70% C, 3.95% H, 11.10% N. 1H NMR (DMSO-d6):
12.00 s, 2 H (2 × OH); 11.20 s, 2 H (2 × NH); 9.18–9.10 m , 2 H (2 × NH-CH); 8.67–8.50 m ,
8 H (βH-n aph th alen e); 8.14–8.12 m , 3 H (pyridin e); 8.01–7.85 m , 4 H (αH-n aph th alen e);
7.30–7.15 m , 8 H (2 × Ph ); 5.20 m , 2 H (2 × CHNH); 3.60 d, 4 H (2 × CH2). Mass spectrum ,
m/z (rel. %): 881 (M+, 9).
This work was supported by the Grant Agency of the Czech Republic (grant No. 203/94/0933).
REFERENCES
1. Lerman L.: J. Mol. Biol. 1961, 3, 18.
2. Waring M. J.: Annu. Rev. Biochem. 1981, 50, 159.
3. Wakelin L. P. G.: Med. Chem. Rev. 1986, 6, 275.
4. Schneider E., Hsiang Y., Liu. L. F.: Adv. Pharmacol. 1990, 21, 149.
5. Wakelin L. P. G., Waring M. J. in: Comprehensive Medicinal Chemistry (P. G. Sammes, Ed.),
Vol. 2, p. 720. Pergamon, Oxford 1990.
6. Johnson D. S., Boger D. L. in: Comprehensive Supramolecular Chemistry (J.-M. Lehn, Ed.),
Vol. 4, p. 73. Pergamon, Oxford 1995.
7. Hurley L. H.: J. Med. Chem. 1989, 32, 2027.
8. Waring M. J., Fox K. R. in: Molecular Aspects of Anti-Cancer Drug Action (S. Neidle and
M. J. Waring, Eds), p. 127. Verlag Chemie, Weinheim 1984.
9. Wilson W. D., Jones R. L.: Adv. Pharmacol. Chemother. 1981, 18, 177.
10. Wakelin L. P. G.: Med. Res. Rev. 1986, 6, 275.
Collect. Czech. Chem. Commun. (Vol. 64) (1999)

298
Amr, Abd El-Salam, Attia, Stibor:
11. Chaires J. B., Leng F., Przewloka T., Fokt I., Ling Y. H., Perez-Soler R., Proiebe W.: J. Med.
Chem. 1997, 40, 261.
12. Bousquet P. F., Braňa M. F., Conlon D., Fitgerald K. M., Perron D., Cocchiaro C., Miller R.,
Moran M., George J., Qian X. D., Keilhauer G., Romerdahl C. A.: Cancer Res. 1995, 55,
1176.
13. Bailly C., Braňa M. F., Waring M. J.: Eur. J. Biochem. 1996, 240, 195.
14. Delepine M., Milhe C., Namane A., Dinh T. H., Roques B. P.: Biopolymers 1991, 31, 331.
15. Denny W. A. in: Cancer. Chemotherapeutic Agents (W. O. Foye, Ed.), p. 218. ACS,
Washington DC 1995.
16. Lokey R. S., Kwok Y., Guelev V., Pusell C. J., Hurley L. H., Iverson B. L.: J. Am. Chem. Soc.
1997, 119, 7202.
17. Waring M. J., Gonzáles A., Jiménez A., Vázquez D.: Nucleic Acids Res. 1979, 7, 217.
18. Braňa M. F., Castellano J. M., Moran M., Perez de Vega M. J., Romerdahl C. A., Qian X. D.,
Bousquet P. F., Emling F., Schlick E., Keilhauer G.: Anti-Cancer Drug Des. 1993, 8, 257.
19. Braňa M. F., Castellano J. M., Moran M., Perez de Vega M. J., Qian X. D., Romerdahl C. A.,
Keilhauer G.: Eur. J. Med. Chem. 1995, 30, 235.
20. Braňa M. F., Castellano J. M., Perron D., Maher C., Conlon D., Bousquet P. F., George J.,
Qian X. D., Robinson S. P.: J. Med. Chem. 1997, 40, 449.
21. Kelly D. P., Mack P. O.-L., Martin R. F., Wakelin L. P. G.: Int. J. Pept. Protein Res. 1985,
26, 400.
22. Corden J. L., Cadena D. L., Ahearu J. M., Jr., Dahmus M. E.: Proc. Natl. Acad. Sci. U.S.A.
1985, 82, 7934.
23. Young R. A.: Annu. Rev. Biochem. 1991, 60, 689.
24. Suzuki M.: Nature 1990, 344, 562.
25. Harding M. M.: J. Med. Chem. 1992, 35, 4658.
26. Huang X., Long E. C.: Bioorg. Med. Chem. Lett. 1995, 5, 1937.
27. Harding M. M., Krippner G. Y., Shelton C. J., Rodger A., Sanders K. J., Mackay J. P.,
Prakash A. P.: Biopolymers 1997, 42, 387.
28. Ranganathan D., Haridas V., Gilari R., Karle I. L.: J. Am. Chem. Soc. 1998, 120, 10793.
29. Roderick A. B., Fales H. M.: J. Am. Chem. Soc. 1953, 75, 975.
30. Graf R., Zettl F.: J. Prakt. Chem. 1936, 147, 188.
31. Supniewski J., Bany T., Krupinska J.: Bull. Acad. Pol. Sci. 1955, 3, 55; Chem. Abstr. 1956,
50, 7800.
Collect. Czech. Chem. Commun. (Vol. 64) (1999)