Med Chem Res
m/z: 352.1 (M+23, 100). Anal. Calcd. for C H FN O : C,
LC-MS (ESI) m/z: 348.1 (M+23, 100). Anal. Calcd. for
1
6
12
3 4
5
8.36; H, 3.67; N, 12.76. Found: C, 58.66; H, 3.41; N,
C H N O : C, 62.76; H, 4.65; N, 12.92. Found: C, 63.01;
1
7 15 3 4
1
2.96.
H, 4.81; N, 12.77.
4
-Methyl-N’-(2-(2-oxobenzo[d]oxazol-3(2H)-yl)acetyl)ben-
3
-Fluoro-N’-(2-(2-oxobenzo[d]oxazol-3(2H)-yl) acetyl)ben-
zohydrazide (4c) Yield 45%; White crystalline powder;
mp 229–230 °C; IR (KBr disk): υ (cm ) 1676–1769
zohydrazide (4f) Yield 50%; White crystalline powder;
mp 219–220 °C; IR (KBr disk): υ (cm ) 1696–1771
−
1
−1
1
(
C=O), 3307–3607 (N–H); HNMR (DMSO-d ): δ (ppm)
1
6
(C=O), 3205–3294 (N–H); HNMR (DMSO-d ): δ (ppm)
6
2
.38 (3H, s, –CH ), 4.62 (2H, s, N–CH –CO), 7.15–7.20
3 2
4
7
7
.66 (2H, s, N–CH –CO), 7.15–7.20 (1H, m, H ),
2
5
(
1H, m, H ), 7.23–7.25 (2H, m, H and H ), 7.28 (2H, d, J
5 4 6
.23–7.25 (2H, m, H and H ), 7.36 (1H, d, J = 7.5 Hz, H ),
4
6
7
=
7.5 Hz, H3’ and H5’ Ar), 7.36 (1H, d, J = 7.5 Hz, H7),
.45 (1H, d, J = 7.5 Hz, H Ar), 7.57 (1H, t, J = 7.5 Hz, H
4
’
5’
7
.76 (2H, d, J = 7.5 Hz, H and H6’ Ar), 10.42 (2H, s,
2
’
Ar), 7.64 (1H, d, J = 10.0 Hz, H Ar), 7.72 (1H, d, J = 7.5
Hz, H6’ Ar), 10.57 (2H, d, J = 22.5 Hz, –NH–); CNMR
1
3
2’
–
NH–); CNMR (DMSO-d ): δ (ppm) 21.0 (CH ), 43.0
13
6
3
(
(
(
CH , N–CH –CO), 109.2 (CH, C ), 109.7 (CH, C ), 122.5
2 2 7 4
CH, C ), 123.9 (CH, C ), 127.5 (CH, C and C Ar), 129.0
CH, C and C Ar), 129.4 (C, C–CO–NH), 131.3 (C,
(DMSO-d ): δ (ppm) 47.7 (CH , N–CH –CO), 114.3 (2CH,
6 2 2
6
5
2
6
C ), 114.4 (CH, C ), 118.8, 119.2 (CH, C Ar, J = 24),
1
7
4
2
3
5
23.5, 123.9 (CH, C Ar, J = 24), 127.2 (CH, C ), 128.4
4
6
C–N), 142.0 (C, C–CH ), 142.5 (C, C–O), 154.0 (C,
N–CO–O), 165.3, 165.5 (2C, CO–NH–NH–CO); LC-MS
3
(CH, C ), 128.7 (CH, C Ar), 135.5, 135.6 (CH, C Ar),
5 6 5
1
36.0 (C, C–N), 139.1, 139.2 (C, C–CO–NH), 146.8 (C,
(
ESI) m/z: 348.1 (M+23, 100). Anal. Calcd. for
C–O), 158.7 (C, N–CO–O), 164.7, 168.6 (C, C–F, J = 240),
C H N O : C, 62.76; H, 4.65; N, 12.92. Found: C, 62.48;
H, 4.31; N, 13.05.
1
7 15 3 4
1
3
5
1
68.9, 170 (2C, CO–NH–NH–CO); LC-MS (ESI) m/z:
52.1 (M+23, 100). Anal. Calcd. for C H FN O : C,
1
6
12
3 4
8.36; H, 3.67; N, 12.76. Found: C, 58.51; H, 3.98; N,
2.64.
4
-Chloro-N’-(2-(2-oxobenzo[d]oxazol-3(2H)-yl)
acetyl)
benzohydrazide (4d) Yield 40%; White crystalline pow-
der; mp 249–251 °C; IR (KBr disk): υ (cm ) 1980–1774
−
1
1
(
C=O), 3286–3354 (N–H); HNMR (DMSO-d ): δ (ppm)
6
General procedure for the preparation of 2-(2-(2-oxobenzo
d]oxazol-3(2H)-yl) acetyl)-N- substituted phenylhydrazine-
4
7
7
7
.63 (2H, s, N–CH –CO), 7.11–7.19 (1H, m, H ),
2
5
[
.23–7.25 (2H, m, H and H ), 7.36 (1H, d, J = 7.5 Hz, H ),
.56 (2H, d, J = 7.5 Hz, H and H Ar), 7.87 (2H, d, J =
4
6
7
carbothioamide (5a–c)
3
’
5’
13
.5 Hz, H2’ and H6’ Ar), 10.56 (2H, d, NH); CNMR
A mixture of compound 3 (3 mmol), substituted phenyl
isothiocyanate (3.1 mmol) and 10 mL absolute ethanol was
refluxed for 4 h. Progress of the reaction was monitored by
thin layer chromatography (TLC). After completion of the
reaction, it was cooled to room temperature. The pre-
cipitated product was filtered and crystallized from ethanol.
(
DMSO-d ): δ (ppm) 43.4 (CH , N–CH –CO), 110.0 (2CH,
6 2 2
C ), 110.1 (CH, C ), 122.9 (CH, C ), 124.3 (CH, C ), 129.1
(
C–CO–NH), 131.6 (C, C–N), 137.2 (C, C–Cl), 142.4 (C,
C–O), 154.4 (C, N–CO–O), 164.9,165.9 (2C,
CO–NH–NH–CO); LC-MS (ESI) m/z: 368.1 (M+23, 100).
Anal. Calcd. for C H ClN O : C, 55.58; H, 3.50; N,
7
4
6
5
CH, C and C Ar), 129.8 (CH, C and C Ar), 131.3 (C,
2 6 3 5
1
6
12
3 4
1
0.25. Found: C, 55.81; H, 3.21; N, 10.44.
2-(2-(2-Oxobenzo[d]oxazol-3(2H)-yl)acetyl)-N-phenylhy-
drazinecarbothioamide (5a) Yield 58%; White crystalline
−
1
3
-Methyl-N’-(2-(2-oxobenzo[d]oxazol-3(2H)-yl)
acetyl)
powder; mp 190.5–192.5 °C; IR (KBr disk): υ (cm 1 ) 1204
(C=S), 1666–1746 (C=O), 2959–3251 (N–H); HNMR
(DMSO-d ): δ (ppm) 4.64 (2H, s, N–CH –CO), 7.16–7.21
benzohydrazide (4e) Yield 40%; White crystalline pow-
der; mp 208–210 °C; IR (KBr disk): υ (cm ) 1678–1768
−
1
6
2
1
(
C=O), 3276–3605 (N–H); HNMR (DMSO-d ): δ (ppm)
(3H, m, H and H and H ), 7.32–7.44 (5H, m, Ar H), 7.37
5 4 6
6
2
.35 (3H, s, –CH ), 4.63 (2H, s, N–CH –CO), 7.15–7.20
(1H, d, J = 7.5 Hz, H ), 9.72 (2H, s, –NH–CS), 10.49 (1H,
s, –NH–CO); CNMR (DMSO-d ): δ (ppm) 43.1 (CH , N–
6 2
3
2
7
1
3
(
1H, m, H ), 7.24–2.25 (2H, m, H and H ), 7.36 (1H, d, J
5
4
6
=
7.5 Hz, H ), 7.42–7.44 (2H, m, H4’ and H5’ Ar),
CH –CO), 109.7 (2CH, C and C ), 122.4, 122.5 (2CH, C
2 4 7 5
7
7
.65–7.68 (2H, m, H and H Ar), 10.47 (2H, s, –NH–);
and C ), 123.9, 124.3 (2CH, C and C Ar), 125.4, 125.9
6 2 6
(CH, C Ar), 128.0, 128.2 (2CH, C and C Ar), 131.2 (C,
4 3 5
2
’
6’
1
3
CNMR (DMSO-d ): δ (ppm) 21.3 (CH ), 43.4 (CH , N–
6
3
2
CH –CO), 110.0 (2CH, C ), 110.1 (CH, C ), 122.9 (CH,
C–N), 139.0 (C, C–NH–CS), 142.0 (C, C–O), 154.1 (C,
N–CO–O), 165.9 (C, CO–NH–NH), 181.0 (C, CS); LC-MS
(ESI) m/z: 343.1 (M+1, 100). Anal. Calcd. for
C H N O S: C, 56.13; H, 4.12; N, 16.36. Found: C,
2
7
4
C ), 124.3 (CH, C ), 124.9 (CH, C Ar), 128.4 (CH, C Ar),
6
5
6
2
1
1
1
28.8 (CH, C Ar), 131.7 (C, C–N), 132.6 (C, C–CO–NH),
5
32.9 (CH, C Ar), 138.0 (C, C–CH ), 142.4 (C, C–O),
4
3
16 14 4 3
54.4 (C, N–CO–O), 165.8, 166.0 (2C, CO–NH–NH–CO);
56.44; H, 4.34; N, 16.10.