434 Ali
trifluoride etherate (0.05 mL) was heated in water
bath for 2 h. After cooling, some water (5 mL) was
added to the mixture to give the solid which was fil-
tered off and crystallized from ethyl acetate to give
pale yellow crystals in 67% yield; mp 109–111◦C.
IR (KBr), (νmax, cm−1): 3319, 3169 (NH, NH),
3050 (C–Harom), 2923 (C–Haliph), 1599 (C N), 1293,
and crystallized from ethanol to give orange crys-
tals in 71% yield; mp 106–108◦C. IR (KBr), (νmax
,
cm−1): 3060 (C–Harom), 2979, 2931 (C–Haliph), 2250
≡
(C N), 1599 (C N), 1543 (C C), 1210 (P O), 1026
(P
O
C). 1H-NMR (DMSO, δ ppm): 1.29 (t, 3H, J =
7.2 Hz, CH3CH2O), 3.29 (s, 2H, CH2CN), 4.29 (q, 2H,
J = 7.2 Hz, CH3CH2O), 7.41–7.95 (m, 10H, Ph−H),
8.20 (s, 1H, C5–Hpyrazole). 13C-NMR (DMSO, δ ppm):
13.9 (CH3CH2O), 55 (CH2), 62.0 (CH3CH2O), 109.2
1218 (P O), 1049 (P
O
C). 1H-NMR (DMSO,
δ ppm): 1.13 (t, 3H, J = 6.9 Hz, CH3CH2O), 1.17 (t,
3H, J = 6.9 Hz, CH3CH2O), 2.20 (d, 6H, J = 15.3 Hz,
CH3–P), 3.95 (q, 2H, J = 6.9 Hz, CH3CH2O), 4.03
(q, 2H, J = 6.9 Hz, CH3CH2O), 4.28 (s, 1H, NH ex-
changeable with D2O), 4.95 (d, 2H, JPCH = 20 Hz,
CH–P), 6.05 (brs, 1H, NH exchangeable with D2O),
7.27–8.18 (m, 10H, Ph−H), 8.67 (s, 1H, C5–Hpyrazole).
13C-NMR (DMSO, δ ppm): 16.2 (CH3CH2O), 25.3
(CH3–P), 46.0 (d, JPC = 150 Hz, CH–P), 62.7
(CH3CH2O), 126.8 (C4 pyrazole), 127.8–140.1 (Phenyl
carbons), 146.7 (C5 pyrazole), 157.6 (C3 pyrazole). 31P-
NMR (DMSO, δ ppm): 22.2 and 35.2 ppm. MS (m/e,
I%): 476 (M+, 0.1), 423 (9), 367 (20), 313 (73), 293
(100), 239 (44), 186 (26), 132 (11), 106 (18), 98 (34),
64 (33). Anal. Calcd for C22H30N4O4P2 (476.46): C,
55.46; H, 6.35; N, 11.76. Found: C, 55.21; H, 6.22; N,
11.49%.
≡
(C N), 126.6 (C4 pyrazole), 127.1–139.1 (phenyl car-
bons), 141.5 (C3 oxadiazaphosphorine), 145.4 (C5 pyrazole),
151.0 (C3 pyrazole), 154.3 (C6 oxadiazaphosphorine). 31P-
NMR (DMSO, δ ppm): 19.0. MS (m/e, I%): 419 (M+,
1.2), 343 (3), 230 (4), 188 (28), 120 (58), 77 (10). Anal.
Calcd for C21H18N5O3P (419.38): C, 60.14; H, 4.33;
N, 16.70. Found: C, 59.81; H, 4.12; N, 16.49%.
P,P-dimethyl-Nꢁ-[1,3-diphenyl-1H-pyrazol-4-
ylmethylidene]phosphinic hydrazide (15)
Method A: a mixture of compound 8 (0.001 mol,
0.329 g) and P,P-dimethylphosphinic hydrazide
(0.001 mol, 0.108 g) in absolute ethanol (15 mL)
containing two drops of triethylamine was heated
under reflux for 8 h. The formed precipitate was fil-
tered off and crystallized from dilute ethanol to give
pale yellow crystals in 78% yield; mp 173–174◦C.
Method B: a mixture of 1,3-diphenyl-1H-pyrazole-
4-carbaldehyde (1) (0.001 mol, 0.248 g) and P,P-
dimethylphosphinic hydrazide (0.001 mol, 0.011 g)
in absolute ethanol (15 mL) was heated under reflux
for 2 h. The formed precipitate was filtered off and
crystallized from ethanol to give pale yellow crystals
in 86% yield; mp 174–176◦C. IR (KBr), (νmax, cm−1):
3387 (br, NH), 3068 (C–Harom), 2980 (C–Haliph), 1599
2-Cyano-Nꢁ-[1,3-diphenyl-1H-pyrazol-4-
ylmethylidene]acetohydrazide (8)
A mixture of 1,3-diphenyl-1H-pyrazole-4-carbal-
dehyde (1) (0.001 mol, 0.248 g) and cyanoaceto-
hydrazide (0.001 mol, 0.099 g) in absolute ethanol
(15 mL) was heated under reflux for 2 h. The formed
precipitate was filtered off and crystallized from di-
lute DMF to give pale yellow crystals in 75% yield;
mp 207–208◦C. IR (KBr), (νmax, cm−1): 3179 (NH),
1
(C N), 1544 (C C), 1209 (P O). H-NMR (DMSO,
≡
3058 (C–Harom), 2968, 2920 (C–Haliph), 2263 (C N),
δ ppm): 2.21 (d, 6H, J = 12.3 Hz, CH3), 6.10 (s,
1H, NH exchangeable with D2O), 7.02–8.18 (m, 10H,
Ph−H), 8.70 (s, 1H, C5–Hpyrazole), 9.98 (s, 1H, CH =
N). MS (m/e, I%): 338 (M+, 13), 246 (51), 245 (100),
121 (59), 93 (45), 77 (64), 65 (15). Anal. Calcd for
C18H19N4OP (338.35): C, 63.90; H, 5.66; N, 16.56.
Found: C, 63.65; H, 5.42; N, 16.29%.
1682 (C O), 1599 (C N), 1550 (C C). 1H-NMR
(DMSO, δ ppm): 4.12 (s, 2H, CH2), 7.39–8.12 (m,
10H, Ph−H), 8.25 (s, 1H, C5–Hpyrazole), 9.01 (s, 1H,
CH = N), 11.62 (s, 1H, NH exchangeable with D2O).
MS (m/e, I%): 329 (M+, 1), 262 (1), 246 (21), 217 (7),
121 (23), 92 (31), 77 (100), 65 (32), 51 (32). Anal.
Calcd for C19H15N5OP (329.36): C, 69.29; H, 4.59; N,
21.26. Found: C, 68.91; H, 4.42; N, 20.93%.
4-(2-Ethoxy-2-oxido-5-phenyl-2,3-dihydro-1,2-
oxaphosphol-3-yl)-1,3-diphenyl-1H-pyrazole(18)
[2-Ethoxy-2-oxido-3-(1,3-diphenyl-1H-pyrazol-
4-yl)-2H-1,4,5,2-oxadiazaphosphinin-6-yl]
acetonitrile (13)
A
mixture of 3-(1,3-diphenyl-1H-pyrazol-4-yl)-1-
phenylprop-2-en-1-one (16) (0.001 mol, 0.350 g), di-
ethyl phosphite (2 mL), and boron trifluoride ether-
ate (0.05 mL) was heated in water bath for 10 h.
After cooling, some water (10 mL) was added to the
mixture to give the solid which was filtered off and
crystallized from methanol to give brown crystals in
57% yield; mp 108–110◦C. IR (KBr), (νmax, cm−1):
A mixture of compound 8 (0.001 mol, 0.329 g) and di-
ethyl phosphite (3 mL), and boron trifluoride ether-
ate (0.05 mL) was heated in water bath for 8 h.
After cooling, some water (10 mL) was added to
the mixture to give the solid which was filtered off
Heteroatom Chemistry DOI 10.1002/hc