Med Chem Res
δ, ppm): 171.1 (C=O of amide), 167.4 (C=O of pyrazol-5-
one), 163.6 (CH=N of imine), 157.4, 147.9, 132.2, 129,
126.6, 124.1, 121.5, 120.5, 113.8, 105.3, 57.5 (OCH3), 35.9
(CH2 of pyrazol-5-one). EIMS m/z (relative intensity):
412.9 (M+ + 1, 16%), 411.1 (35%), 381.1 (21%), 292.1
(100%), 230.0 (15%), 195.3 (42%), 158.1 (20%), 124.9
(29%), 91 (33%). HRMS (EI): for C19H14FN5O3S [M+ +
H], calcd. 413.0086 m/z; found, 413.0111 m/z.
MHz, DMSO-d6, δ, ppm): 10.25 (brs, 1H, NH), 8.89 (s, 1H,
CH=N of imine), 8.01 (s, 1H, H-7 of benzo[d]thiazole),
7.82–7.79 (d, 2H, J = 8.2 Hz, H-4 and H-5 of benzo[d]
thiazole), 7.42–7.40 (d, 2H, J = 8.5 Hz, Ar–H), 7.21–7.18
(d, 2H, J = 8.6 Hz, Ar–H), 3.42 (s, 2H, –CH2 of pyrazol-5-
one). 13C NMR (101 MHz, DMSO-d6, δ, ppm):172.6 (C=O
of amide), 168.1 (C=O of pyrazol-5-one), 163.1 (CH=N of
imine), 156.3, 147.3, 131.2, 129.3, 127.1, 123.4, 121.9,
120.9, 114.4, 105.5, 35.8 (CH2 of pyrazol-5-one).
3-(4-(N,N-dimethylamino)benzylideneamino)-N-(6-
fluorobenzo[d]thiazol-2-yl)-4,5-dihydro-5-oxo-pyrazole-1-
carboxamide (5c)
3-(Benzylideneamino)-N-(6-chlorobenzo[d]thiazol-2-yl)-
4,5-dihydro-5-oxo-pyrazole-1-carboxamide (5f)
Yield 46.3%, mp 158–160 °C; FTIR (KBr, cm−1): 3297
(N–H), 3064 (Ar–H), 1693 (C=O of amide), 1661 (C=O of
pyrazol-5-one), 1610 (C=N), 746 (C–S–C); 1H NMR (400
MHz, DMSO-d6, δ, ppm): 9.97 (brs, 1H, NH), 8.9 (s, 1H,
CH=N of imine), 8.08 (s, 1H, H-7 of benzo[d]thiazole),
7.68–7.65 (d, 2H, J = 8.7 Hz, H-4 and H-5 of benzo[d]
thiazole), 7.30–7.27 (d, 2H, J = 8.2 Hz, Ar–H), 7.15–7.12
(d, 2H, J = 8.3 Hz, Ar–H), 3.31 (s, 2H, –CH2 of pyrazol-5-
one), 2.92 (s, 6H, N(CH3)2). 13C NMR (101 MHz, DMSO-
d6, δ, ppm): 172 (C=O of amide), 168.2 (C=O of pyrazol-
5-one), 163.2 (CH=N of imine), 156.9, 148, 132.7, 129.5,
127.2, 123.2, 121.2, 120.3, 114.2, 106.8, 44.6 (–N(CH3)2),
36.3 (CH2 of pyrazol-5-one). EIMS m/z (relative intensity):
425.3 (M+ + 1, 41%), 379.1 (28%), 293.1 (100%), 230.2
(60%), 195.2 (21%), 157.5 (38%), 124.9 (14%), 91.3
(32%). HRMS (EI): for C20H17FN6O2S [M+ + H], calcd.
425.0011 m/z; found, 425.0614 m/z.
Yield 64.2%, mp 237–239 °C; FTIR (KBr, cm−1): 3279
(N–H), 3044 (Ar–H), 1696 (C=O of amide), 1654 (C=O of
pyrazol-5-one), 1601 (C=N), 733 (C–S–C). 1H NMR (400
MHz, DMSO-d6, δ, ppm): 10.31 (brs, 1H, NH), 8.72 (s, 1H,
CH=N of imine), 7.97 (s, 1H, H-7 of benzo[d]thiazole),
7.66–7.61 (d, 2H, J = 8.7 Hz, H-4 and H-5 of benzo[d]
thiazole), 7.40–7.37 (d, 2H, J = 8.5 Hz, Ar–H), 7.14–7.11
(m, 3H, Ar–H), 3.33 (s, 2H, –CH2 of pyrazol-5-one). 13C
NMR (101 MHz, DMSO-d6, δ, ppm): 174.9 (C=O of
amide), 168.2 (C=O of pyrazol-5-one), 163.1 (CH=N of
imine), 155.8, 147.4, 131, 128.2, 127.5, 126.6, 123.9,
120.4, 115.1, 107.3, 37.1 (CH2 of pyrazol-5-one). EIMS
m/z (relative intensity): 398.1 (M+ + 1, 26%), 321.6 (13%),
308.4 (100%), 229.8 (62%), 165.4 (37%), 124.4 (19%),
91.4 (27%). HRMS (EI): for C18H12ClN5O2S [M+ + H],
calcd. 398.0405 m/z; found, 398.0389 m/z.
3-(4-Chlorobenzylideneamino)-N-(6-fluorobenzo[d]thiazol-
2-yl)-4,5-dihydro-5-oxo-pyrazole-1-carboxamide (5d)
3-(4-Methoxybenzylideneamino)-N-(6-chlorobenzo[d]
thiazol-2-yl)-4,5-dihydro-5-oxo-pyrazole-1-carboxamide
(5g)
Yield 69.4%, mp 191–194 °C; FTIR (KBr, cm−1): 3252
(N–H), 3080 (Ar–H), 1684 (C=O of amide), 1670 (C=O of
pyrazol-5-one), 1596 (C=N), 729 (C–S–C); 1H NMR (400
MHz, DMSO-d6, δ, ppm): 10.09 (brs, 1H, NH), 9.06 (s, 1H,
CH=N of imine), 8.09 (s, 1H, H-7 of benzo[d]thiazole),
7.84–7.82 (d, 2H, J = 8.5 Hz, H-4 and H-5 of benzo[d]
thiazole), 7.38–7.34 (d, 2H, J = 8.7 Hz, Ar–H), 7.08–7.01
(d, 2H, J = 8.5 Hz, Ar–H), 3.50 (s, 2H, –CH2 of pyrazol-5-
one). 13C NMR (101 MHz, DMSO-d6, δ, ppm): 172.3
(C=O of amide), 167.8 (C=O of pyrazol-5-one), 162.9
(CH=N of imine), 157.2, 147.8, 130.9, 128.9, 126.9, 124.3,
122.3, 120.7, 113.4, 107.1, 36.1 (CH2 of pyrazol-5-one).
Yield 50.7%, mp 192–194 °C; FTIR (KBr, cm−1): 3289
(N–H), 3054 (Ar–H), 1672 (C=O of amide), 1645 (C=O of
pyrazol-5-one), 1593 (C=N), 759 (C–S–C). 1H NMR (400
MHz, DMSO-d6, δ, ppm): 10.42 (brs, 1H, NH), 9.06 (s, 1H,
CH=N of imine), 7.95 (s, 1H, H-7 of benzo[d]thiazole),
7.65–7.62 (d, 2H, J = 8.4 Hz, H-4 and H-5 of benzo[d]
thiazole), 7.33–7.30 (d, 2H, J = 8.7 Hz, Ar–H), 7.12–7.08
(d, 2H, J = 8.9 Hz, Ar–H), 3.82 (s, 3H, OCH3), 3.27 (s, 2H,
–CH2 of pyrazol-5-one). 13C NMR (101 MHz, DMSO-d6,
δ, ppm): 174.1 (C=O of amide), 168.3 (C=O of pyrazol-5-
one), 161.8 (CH=N of imine), 155.2, 148.3, 131.8, 127.8,
127.4, 125.4, 123.4, 121.3, 120.9, 115.2, 108.8, 58.3
(OCH3), 37.5 (CH2 of pyrazol-5-one). EIMS m/z (relative
intensity): 428.3 (M+ + 1, 33%), 323.2 (18%), 307.9
(100%), 230.4 (20%), 165.1 (53%), 126.0 (44%), 91.6
(21%). HRMS (EI): for C19H14ClN5O3S [M+ + H], calcd.
428.0510 m/z; found, 428.0532 m/z.
3-(4-Nitrobenzylideneamino)-N-(6-fluorobenzo[d]thiazol-
2-yl)-4,5-dihydro-5-oxo-pyrazole-1-carboxamide (5e)
Yield 60.7%, mp 202–206 °C; FTIR (KBr, cm−1): 3302
(N–H), 3069 (Ar–H), 1689 (C=O of amide), 1652 (C=O of
pyrazol-5-one), 1599 (C=N), 736 (C–S–C). 1H NMR (400