Â
A. Jonczyk et al. / Tetrahedron 57 (2001) 2827±2832
2831
Isomeric pyrazoles 15 mp 124±1268C, one signal on GC;
(Found: C, 73.3; H, 5.4; N, 21.4; C12H11N3 requires C,
73.07; H, 5.62; N, 21.30%); nmax (KBr) 3132, 3104, 3016,
dissolved in CHCl3, passed through short column with
Kieselgel (eluent: ethyl acetate/hexane 5:1), the eluate was
evaporated and the residue was crystallized from acetone, to
give 18 (0.25 g, 8%), mp 216±2188C; (Found: C 77.6, H
5.9, N 11.8. C23H21N3O requires C, 77.72; H, 5.96; N,
11.82%); nmax (KBr) 3436, 3276, 3208, 3164, 1676, 1596,
1560, 1444, 1276, 1252, 767, 740, 700 cm21; dH (200 MHz)
7.40±7.23 (15H, m, Ph), 6.40 (1H, br s, CONH), 5.14 (1H,
br s, CONH), 3.95 (2H, s, CH2), 3.74 (2H, s, CH2); dC
(100 MHz) 164.2, 143.1, 143.6, 137.9, 128.4, 128.3,
127.7, 127.6, 127.1, 80.1, 77.2, 53.5, 48.0.
2936, 2876, 2248, 1572, 1496, 1004, 828, 764, 684 cm21
;
dH (200 MHz) 12.65 (1H, br s, NH), 7.90±7.38 (5H, m, Ph),
6.84 and 6.72 (1H, two s, HCvC), 3.39±2.75 (4H, four
overlapping t, CH2CH2CN); dC (100 MHz) 147.3, 146.9,
146.0, 131.0, 129.5, 129.4, 129.0, 128.8, 126.5, 125.9,
118.9, 118.4, 102.2, 77.2, 23.4, 17.3, 17.1; m/z 197 (89,
M1), 170 (33), 157 (100), 128 (34), 102 (8), 77 (12), 52
(4%).
1.2.8. Reaction of 3-phenylpyrazole (21) with acrylo-
nitrile (3b). Pyrazole 21 (1.44 g, 10 mmol), 50% aq.
NaOH (5 mL), dioxane (10 mL) and nitrile 3b (1.00 g,
19 mmol) were stirred at 808C for 0.5 h. The mixture was
cooled, diluted with water, extracted with Et2O (2£ 20 mL),
the organic extracts were washed with water, dried
(MgSO4), and the solvent was evaporated. The residue
was crystallized (Et2O/light petroleum (ca. 3:1) mixture)
to give 22 (1.01 g, 51%), mp 50±528C, lit.16 mp 51±538C;
(Found: C; 72.85; H, 5.6; N, 21.0; C12H11N3 requires C,
73.07; H, 5.62; N, 21.30%); nmax (CCl4) 2260 cm21; dH
(CCl4, 100 MHz) 7.74±7.64 (2H, m, Ph), 7.39±7.19 (4H,
m with overlapped d, J2.6 Hz, Ph and HCvC), 6.44 (1H,
d, J2.6 Hz, HCvC), 4.24 (2H, t, J6.8 Hz, NCH2), 2.81
(2H, t, J6.8 Hz, CH2CN).
1.2.5. Preparation of pyrazoline 7. A solution of diazo-
compound 2a (2.50 g, 12.9 mmol) and triethylamine
(1.44 g, 14.2 mmol) in hexane (55 mL) was added dropwise
to a solution of nitrile 3b (0.76 g, 14.3 mmol) in hexane
(55 mL), and the mixture was stirred with magnetic stirrer
for 48 h. The solid was ®ltered off and crystallised (EtOH)
to give 1.46 g (46%) of 7, mp 108±1138C (dec.). (Found: C,
77.7; H, 5.3; N, 16.65; C16H13N3 requires: C, 77.71; H, 5.30;
N, 16.99%); nmax (KBr) 3316, 3276, 2216, 1544, 1492,
1444, 1420, 1312, 760, 700, 612 cm21; dH (200 MHz)
7.42±7.15 (10H, m, Ph), 6.86 (1H, s, NH), 3.51 (2H, s,
CH2); dC (50 MHz) 143.7, 128.8, 128.0, 126.1, 121.7,
114.5, 75.9, 46.8.
1.2.6. Preparation of cyclopropane 9 from reaction of
pyrazoline 7 with acrylonitrile (3b). Pyrazoline 7
(0.50 g, 2 mmol), dioxane (2 mL), 50% aq. NaOH (2 mL)
and TBABr (0.06 g, 0.19 mmol) were stirred (the mixture
thickened and the solid separated), then 3b (0.64 g,
12 mmol) was added dropwise (the solid dissolved), and
the temperature raised from 25 to ca. 428C. The stirring
was continued for 20 min, the mixture was diluted with
water (ca. 50 mL), extracted with CHCl3 (3£20 mL), the
organic extracts were washed with water (50 mL), dried
(MgSO4), the solvent was evaporated, and the residue was
crystallised (MeOH) to give 9 (0.25 g, 46%), mp 136±
1.2.9. Reaction of tosylhydrazone 1b with 3a in the
presence of 14% aq. NaOH. Tosylhydrazone 1b (0.55 g,
2 mmol), benzene (50 mL), TEBAC (0.1 g, 0.4 mmol) and
14% aq. NaOH (50 mL) were stirred at 65±708C for 2 h.
Then, nitrile 3a (0.8 g, 12 mmol) was added and the reaction
continued at 65±708C for 45 min (after 15 min pink colour
faded). The mixture was cooled, diluted with water (50 mL),
the phases were separated, the water phase was extracted
with benzene (2£20 mL), the combined organic extracts
were washed with water, dried (MgSO4) and the solvent
was evaporated. The yellowish solid (0.4 g) was re¯uxed
with hexane (ca. 20 mL) and ®ltered to give colourless
crystals of pyrazole 12 (0.2 g, 68%), mp 124±1268C.
1
1388C, identi®ed by comparison (mixed mp, TLC, GC, H
NMR) with that obtained from 1a and 3b.
1.2.7. Reaction of pyrazoline 7 with benzyl chloride.
Pyrazoline 7 (2.47 g, 10 mmol), benzyl chloride (1.53 g,
20 mmole), dioxane (3 mL), 50% aq. NaOH (15 mL) and
TBAB (0.3 g, 0.9 mmol) were stirred at ca. 608C for 6 h (the
solid that was formed at the beginning, dissolved later). The
mixture was diluted with water, extracted with benzene
(3£20 mL), the organic extracts were washed with water,
dried (MgSO4), and the solvent was evaporated. The semi-
Analytical sample of 12 was crystallized from EtOH, mp
1278C (lit.17 mp 1288C); nmax (HCCl3) 3440 cm21; dH
(100 MHz) 7.73±7.63 (2H, m, Ph), 7.41±7.04 (3H, m,
Ph), 6.28 (1H, s, HCvC), 2.21 (3H, s, CH3).
1.2.10. Reaction of diazoalkane 2a with acrylonitrile
(3b). Diazoalkane 2a prepared2 from tosylhydrazone 1a
(10 mmol) was re¯uxed with 3b (1.1 g, 20 mmol) in
benzene (25 mL) until the red colour faded, the solvent
was evaporated and the solid was crystallized (EtOH) to
give 10 (1.14 g, 52%), mp 1078C, lit.8 mp 107±1088C.
1
solid orange residue (3.8 g) was analyzed by H NMR to
show largely the signals of 18 and 20, partially overlapped
with the signals of impurities. This mixture was twice
crystallized (MeOH) to give 20 (0.62 g, 20%), mp 171±
1738C; (Found: C, 89.1; H, 6.1, N, 4.4; C23H19N requires:
C, 89.28; H, 6.19; N, 4.53%); nmax (KBr) 3064, 3028, 2232,
1596, 1496, 1448, 1080, 704 cm21; dH (200 MHz) 7.59±
7.14 (15H, m, Ph), 3.15 (1H, d, J5.4 Hz, CHH), 2.18
(1H, d, J5.4 Hz, CHH), 2.04 and 1.92 (each 1H, AB q,
J5.4 Hz, CH2 cycloprop.); dC (100 MHz) 141.2, 139.1,
137.1, 129.3, 129.2, 128.9, 128.8, 128.7, 128.6, 127.7,
127.6, 127.1, 121.6, 43.6, 38.7, 25.1, 23.4.
1
The product was compared (mixed mp, H NMR) with
that obtained according to lit.1,8
References
Â
1. Jonczyk, A.; Wøostowska, J.; MaÎkosza, M. Bull. Soc. Chim.
Belg. 1977, 86, 739.
Â
2. Jonczyk, A.; Wøostowska J. Synth. Commun. 1978, 8, 569.
3. Regitz, M.; Maas, G. Diazocompounds, Properties and
The ®ltrate after ®rst crystallisation was evaporated,