2490
A. Kumar et al. / Bioorg. Med. Chem. Lett. 16 (2006) 2484–2491
20. Sharma, P.; Kumar, A.; Rane, N.; Gurram, V. Tetrahe-
dron 2005, 61, 4237.
21. Sharma, P.; Kumar, A.; Sharma, S.; Rane, N. Bioorg.
Med. Chem. Lett. 2005, 5, 937.
22. Sharma, P.; Kumar, A.; Sharma, M. J. Mol. Catal. 2005,
237, 191.
23. Sharma, P.; Sharma, S.; Rane, N. Bioorg. Med. Chem.
2004, 12, 3135.
24. Sharma, P.; Rane, N.; Gurram, V. K. Bioorg. Med. Chem.
Lett. 2004, 14, 4185.
25. Sharma, P.; Kumar, A.; Pandey, P. Phosphorus, Sulfur
Silicon Relat. Elem. 2003, 178, 583.
residue was concentrated to 25 mL and left in refrigerator
overnight, when yellow to reddish yellow coloured solid was
deposited which was filtered and dried in vacuum.
30. General procedure for the synthesis of 10-methyl-6-oxo-5-
arylazo-6,7-dihydro-5H-[1,3]azaphospholo[1,5-d][1,4]ben-
zodiazepin-2-phospha-3-ethoxycarbonyl-1-phosphorus
dichlorides (11a–p): To 5-bis(dichlorophosphino)-ylidene-
(3S)-N-ethoxycarbonyl-7-methyl-3-arylazo-2-oxo-1,2,3,5-
tetrahydro-5H-1,4-benzodiazepine (0.01 M), which was
cooled to 0–5 °C under stirring acetonitrile (40 mL) was
added. To this a solution of triethylamine (4.04 g, 0.04 M)
was also added slowly to the reaction mixture till the
development of yellow colour. After stirring for 30 min a
solution of PCl3 (1.37 g, 0.01 M) was added drop wise till
the reaction mixture turns pale yellow to brown. The
reaction mixture was allowed to attain the room temper-
ature and stirring was continued for 10 h. Now the solvent
was evaporated in vacuum and the white shiny crystals of
11a–p were obtained.
26. Sternbach, L. H.; Reeder, E. J. Org. Chem. 1961, 26, 4936.
27. Experimental: Analytical grade chemicals and solvents
were always employed. Solvents were distilled under
nitrogen atmosphere prior to use. Standard syringe and
separation techniques were used for transferring the
reactants and the product mixture. All reactions were
carried out under nitrogen atmosphere. The product
mixtures were analyzed by thin-layer chromatography
(TLC) on silica gel sheets (Merck silica gel-G). IR spectra
(in cmꢀ1) were recorded on Perkin Elmer 377 spectropho-
31. Analytical data of compound 5b: mp 151–152 (°C), yield
72%; IR KBr (m cmꢀ1) 3350 (N–H), 3050 (C–H, sp2), 2850
(C–H, sp3), 2020 (N@N), 1710 (C@O), 1620 (C@C/C@N),
1
tometer. H NMR and 31P NMR spectra were recorded
1580, 1490, 1450 (
, ring str), 920, 850, 740 (sub
……
C
C
on JEOL EX400 and on Bruker DRX 300 MHz spec-
trometers, respectively in DMSO-d6 or CDCl3 chemical
phenyl), 1H NMR (d) ppm 0.92 (s, 3H, CH3, azepine ring),
1.11 (q, 2H, –CH2CH3), 2.35 (s, 3H, CH3-u), 2.52 (s, CH,
azepine ring), 3.41 (t, 3H, –CH2CH3), 3.82 (s, 2H, CH2–
N), 7.12 (d, H8), 7.25 (s, H6), 7.42 (d, H9), 7.59 (s, 5H,
C6H5), 8.20 (s, NH), MS (FAB): M+H+ peak at m/z 305.
Elemental analyses, found (calcd) (%) C, 70.57 (70.66); H,
5.92 (6.05); N, 18.29 (18.32).
1
shifts are given in d ppm using TMS (for H NMR) as an
internal standard and 85% H3PO4 (for 31P NMR) as an
external standard. Mass spectral analysis was performed
using FAB technique. General procedure for the synthesis
of (3S)-3-arylazo-5,7-dimethyl-1,3-dihydro-2H-1, 4-ben-
zodiazepin-2-one (5a–p): To a stirred, cooled (10 °C)
solution of 0.1 M of the 2-aminoacetophenone in 40 mL
of 1,4-dioxan, 0.13 M of chloroacetylchloride and an
equivalent amount of 3 N sodium hydroxide solution was
added in small portions. The reactants were introduced
alternatively at such a rate as to keep the temperature
below 10 °C and the mixture neutral or slightly alkaline.
The reaction was completed after 30 min. The neutral
mixture was diluted with ice and water, and extracted with
methylene chloride. The extract was washed with water,
filtered, dried concentrated in vacuum, and the residue
crystallized. Thus, obtained chloroacetamidoacetophe-
none 2 (0.01 M) in 200 mL of a 20% (w/v) solution of
ammonia in methanol was stirred for 24 h at room
temperature. The methanolic ammonia filtrate obtained
after the separation of 3 was concentrated to dryness in
vacuum, and residue recrystallized to give cyclized ben-
zodiazepin-2-one nucleus 4, which was further, allowed to
react with benzene diazonium chloride (0.01 M) under
thorough stirring for 3–4 h to obtain 5a–p.
32. Analytical data of compound 6a: mp 162–163 (°C), yield
78%;IR KBr (m cmꢀ1) 3350 (N–H), 3050 (C–H, sp2), 2850
(C–H, sp3), 2020 (N@N), 1710 (C@O), 1620 (C@C/C@N),
……
1580, 1490, 1450 (
, ring str), 920, 850, 740 (sub
C
C
phenyl), 1H NMR (d) ppm 1.05 (s, 3H, CH3, azepine ring),
1.21 (q, 2H, –CH2CH3), 2.25 (s, 3H, CH3-u), 2.63 (s, CH,
azepine ring), 3.30 (t, 3H, –CH2CH3), 3.94 (s, 2H, CH2–
N), 7.09 (d, H8), 7.30 (s, H6), 7.46 (d, H9), 7.75 (s, 5H,
C6H5), 8.05 (s, NH), MS (FAB): M+H+ peak at m/z 290.
Elemental analyses, found (calcd) (%) C, 66.47 (66.59); H,
6.11 (6.18); N, 14.77 (14.85).
33. Analytical data of compound 9a: mp (°C) 146–147, yield
68%; IR KBr (m cmꢀ1) 3330 (N–H), 3050 (C–H, sp2), 2840
(C–H, sp3), 1980 (N@N), 1710 (C@O), 1630 (C@C/C@N),
……
1580, 1490, 1470 (
, ring str), 1430 (C–P), 930, 820,
C
C
1
710 (sub. phenyl), 570 (P–Cl), H NMR (d) ppm 1.12 (t,
3H, –CH2CH3), 2.25 (s, 3H, CH3-u), 3.40 (s, CH, azepine
ring), 4.05 (s, 2H, CH2–N), 4.60 (q, 2H, –CH2CH3), 6.85
(d, H8), 7.20 (s, 4H, C6H4), 7.30 (d, H6), 7.60 (d, H9), 9.5
(s, NH), 31P NMR 145.6 (dPA), MS (FAB): M+H+ peak at
m/z 595. Elemental analyses, found (calcd) (%) C, 57.01
(57.13); H, 5.47 (5.51); N, 12.66 (12.78).
28. General procedure for the synthesis of N-ethoxycarbonyl-
5,7-dimethyl-2-oxo-3-arylazo-2,3-dihydro-1H-1,4-benzo-
diazepinium chlorides (6a–p): In a 250 mL round bottom
flask to a solution of alkyl halide (0.1 M) in tetrahydrofu-
ron (50 mL), (3S)-3-arylazo-5,7-dimethyl-1,3-dihydro-2H-
1,4-benzodiazepin-2-one 5a–p (0.01 M) was added and
reaction mixture was stirred for 24–48 h at room temper-
ature. The white precipitate obtained was filtered, washed
with diethyl ether (30 mL), dried in vacuum and were used
without further purification.
29. General procedure for the synthesis of 5-bis(dic-
hlorophosphino)-ylidene-(3S)-N-ethoxycarbonyl-7-meth-
yl-3-arylazo-2-oxo-1,2,3,5-tetrahydro-5H-1,4-benzodiaze-
pine (9a–p): In a closed vessel containing compound 6a–p
(0.01 M) in 40 mL toluene, triethylamine (2.02 mL) was
added at room temperature and the reaction mixture was
stirred for 1–2 h. To this mixture a solution of PCl3 (1.37 g,
0.01 M) was added slowly and allowed to stir further for
24 h. The solvent was thereafter removed in vacuum and
34. (a) Analytical data of compound 11a: mp (°C) 256–257,
yield 72%; IR KBr (m cmꢀ1) 3274 (N–H), 3010 (C–H, sp2),
2118 (C–Hasym, sp3), 2852 (C–Hsym, sp3), 1735 (C–O,
ester), 1710 (C@O), 1555 (N@N), 1500, 1464, 1377
……
(
, ring str), 1308 (C–P), 722, 700 (sub phenyl), 550
C
C
(P–Cl),1H NMR (d) ppm 1.42 (t, 3H, CH3), 2.30 (s, 3H,
CH3-u), 4.76 (q, 2H, CH2), 7.33 (m, 3H, Ar-H), 7.49 (s,
5H, C6H5), 9.50 (s, NH), 31P NMR 36.5 (dPA) 166.7 (dPB),
MS (FAB): M+H+ peak at m/z 506. Elemental analyses,
found (calcd) (%) C, 49.72 (49.85); H, 3.58 (3.60); N, 11.05
(11.13).; (b) Analytical data of compound 11b: mp (°C)
232–233, yield 82%; IR KBr (m cmꢀ1) 3250 (N–H), 3040
(C–H, sp2), 2920, (C–Hasym, sp3), 2852 (C–Hsym, sp3), 1735
……
(C@O), 1620 (C@C/C@N), 1600, 1466, 1376 (
, ring
C
C
str), 1540 (N@N), 1118 (C–P), 909, 736 (sub phenyl), 649
(P–Cl), 1H NMR (d) ppm 1.12 (t, 3H, –CH2CH3), 2.15 (s,
3H, CH3-u), 3.15 (s, CH, azepine ring), 4.36 (q, 2H,