7488
I. Nagy et al. / Tetrahedron 59 (2003) 7485–7489
(100 MHz, CDCl3) 164.8, 136.2, 135.3, 135.1, 130.9, 129.8,
120.8, 113.4, 42.4 (N–CH3). Anal. calcd for C12H13ClN6
(276.72), C: 52.08, H: 4.74, N: 30.37; found C: 52.11, H:
4.67, N: 30.33.
4.4.2. 1-(4-Fluorophenyl)-3-[(1E,3E)-3-(dimethyl-hydra-
zono)prop-1-en-1-yl]-1H-pyrazole-4-carbonitrile (14b).
98 mg, 69%. Yellow crystals (1308C, 30 h); mp 150–
1538C (CH3CN); nmax (KBr) 2222, 1624, 1537, 1516, 1420,
1347, 1218, 1062, 965. 836 cm21; dH (200 MHz, CDCl3)
8.17 (1H, s, 5-H), 7.62–7.68 (AA0), 7.430 (1H, dd, J¼16.1,
9.2 Hz, 20-H),0 7.02–7.22 (3H, m, BB0, 3 -H), 6.58 (1H, d,
J¼16.1 Hz, 1 -H), 3.00 (6H, s, N–CH3); dC (100 MHz,
CDCl3) 164.3, 153.1, 135.0, 133.4, 132.5, 131.9, 121.3
(JC,F¼8.3 Hz), 117.4, 116.4 (JC,F¼23.2 Hz), 113.5 (CuN),
92.1, 42.5 (N–CH3). Anal. calcd for C15H14FN5 (283.30),
C: 63.59, H: 4.98, N: 24.72; found C: 63.29, H: 4.78, N:
24.90.
4.3.2. 2-(4-Fluorophenyl)-5[(1E,3E)-5-(dimethylhydra-
zono)-prop-1-en-1-yl]-2H-tetrazole (13b). 0.19 g, 76%.
Pale yellow crystals; mp 127–1288C (CH3CN); 1627, 1552,
1510, 1050, 998, 836 cm21; dH (200 MHz, CDCl3) 8.08–
8.15 (AA0),07.56 (1H, dd, J¼15.9, 9.1 Hz, 20-H), 7.20–7.30
(3H, m, BB , 30-H), 6.70 (1H, d, J¼15.9 Hz, 10-H), 3.04 (6H,
s, N–CH3); dC (100 MHz, CDCl3) 165.3, 160.3, 135.5,
121.6, 121.5 (JC,F¼8.6 Hz), 116.8, 116.4 (JC,F¼23.1 Hz),
114.7, 42.7 (N–CH3). Anal. calcd for C12H13FN6 (260.27),
C: 55.38, H: 5.03, N: 32.29; found C: 55.38, H: 4.95, N:
32.11.
4.4.3. 1-(4-Isopropylphenyl)-3-[(1E,3E)-3-(dimethyl-
hydrazono)prop-1-en-1-yl]-1H-pyrazole-4-carbonitrile
(14c). 65 mg, 42%. Yellow crystals (1408C, 40 h); mp 101–
1028C (diisopropylether); nmax (KBr) 3137, 2959, 2228,
4.3.3. 2-(4-Isopropylphenyl)-5[(1E,3E)-5-(dimethylhy-
drazono)-prop-1-en-1-yl]-2H-tetrazole (13c). 0.17 g,
61%. Beige crystals; mp 105–1068C (CH3CN); nmax
(KBr) 2967, 1630, 1552, 1513, 1471, 1420, 1350, 1197,
1056, 998, 974, 833 cm21; dH (200 MHz, CDCl3) 7.99–
8.04 (AA0), 7.59 (1H, dd, J¼9.2, 16.1 0Hz, 20-H), 7.36–7.40
(BB0), 7.09 (1H, d, J¼9.2 Hz, 3 -H), 6.68 (1H, d,
J¼16.1 Hz, 10H), 3.02 (7H, m, N–CH3, CH), 1.30 (6H, d,
J¼7.0 Hz, CH3); dC (100 MHz, CDCl3) 164.5, 150.5, 135.6,
134.8, 131.3, 127.5, 119.6, 119.0, 42.4 (N–CH3), 33.8
(CH), 23.8 (CH3). Anal. calcd for C15H20N6 (284.36),
C: 63.36, H: 7.09, N: 29.55; found C: 63.45, H: 7.18, N:
29.49.
1626, 1533, 1517, 1422, 1346, 1046, 970, 957, 839 cm21
;
dH (200 MHz, CDCl3) 8.18 (1H, s), 7.55–7.59 (AA0), 7.44
(1H, dd, J¼16.1, 9.0 Hz), 7.30–7.37 (BB0), 7.06 (1H, d,
J¼9.0 Hz), 6.61 (1H, d, J¼16.1 Hz), 2.99 (6H, s, N–CH3),
2.93 (1H, m, CH), 1.27 (6H, d, J¼6.5 Hz, CH3); dC
(100 MHz, CDCl3) 152.8, 149.0, 133.0, 132.3, 132.2, 127.6,
119.6, 117.8, 91.7, 42.4, 33.7, 23.8. Anal. calcd for
C18H21N5 (307.39), C: 70.33, H: 6.89, N: 22.78; found C:
70.29, H: 6.91, N: 22.89.
4.4.4. [2-(4-Isopropylphenylazo)-pyrrol-1-yl]-dimethyl-
amine (15c). Yellow oil, yield: 10% (1408C, 40 h); dH
(200 MHz, CDCl3) 7.72–7.77 (AA0), 7.30–7.34 (BB0),
7.05 (1H, dd, J¼3.1, 2.5 Hz, pyrrol b-H), 6.58 (1H, dd,
J¼4.0, 2.5 Hz, pyrrol d-H), 6.12 (1H, dd, J¼4.0, 3.1 Hz,
pyrrol g-H), 3.15 (6H, s, N–CH3), 2.97 (1H, m, CH),
1.28 (6H, d, J¼7.0 Hz, CH3); dC (100 MHz, CDCl3)
150.2, 146.8, 133.2, 127.0, 124.8, 122.1, 107.1, 97.9,
48.1, 34.0, 23.9; HRMS (EI): Mþ, found 256.3466.
C15H20N4 requires 256.3461.
4.4. General procedure for the ring transformation of
the 4-tetrazolyl-1-dimethylamino-1-azadienes to
pyrazolyl derivatives 14 and 16
A mixture of the appropriate tetrazolylazadiene or tetra-
zolylacrolein (13 or 12, respectively, 0.5 mmol), fumaroni-
trile (0.23 g, 2.93 mmol) in xylene (10 mL) was stirred
under an argon atmosphere at 140 or 1308C, and the reaction
was monitored by TLC. After completion of the reaction,
the solvent was removed in vacuo, and the residue was
purified by preparative layer chromatography, (hexane/ethyl
acetate (2:1) as an eluent). The separation allowed also the
detection of the pyrrol derivative 15 in traces (higher Rf
value), and in case of transformation of 13c, [2-(4-
isopropyl-phenylazo)-pyrrol-1-yl]-dimethyl-amine (15c)
was also isolated by chromatography, and identified by
1H- and 13C NMR spectroscopy.
4.4.5. 1-(4-Chlorophenyl)-3-[(1E)-3-oxoprop-1-en-1-yl]-
1H-pyrazole-4-carbonitrile (16a). 69.6 mg, 54%. Beige
crystals (1408C, 22 h); mp 146–1498C (CH3CN); nmax
(KBr) 2235, 1691, 1534, 1499, 1215, 1113, 1058, 977, 958,
827 cm21; dH (200 MHz, CDCl3) 9.78 (1H, d, J¼7.6 Hz,
CHO), 08.36 (1H, s, 5-H), 7.65–7.69 (AA0), 7.48–70.56 (3H,
m, BB , 10-H), 7.16 (1H, dd, J¼16.3, 7.6 Hz, 2 -H); dC
(100 MHz, CDCl3) 192.9 (CvO), 149.8, 138.6, 136.8,
134.7, 133.4, 132.4, 130.1, 121.0, 112.1 (CuN), 94.6. Anal.
calcd for C13H8ClN3O (257.68), C: 60.60, H: 3.13, N:
16.31; found C: 60.50, H: 3.19, N: 16.45.
4.4.1. 1-(4-Chlorophenyl)-3-[(1E,3E)-3-(dimethyl-hydra-
zono)prop-1-en-1-yl]-1H-pyrazole-4-carbonitrile (14a).
94.4 mg, 63%. Pale yellow crystals (1308C, 72 h); mp
162–1638C (iPrOH); nmax (KBr) 3129, 2225, 1626, 1533,
1499, 1421, 1352, 1288, 1221, 1054, 955, 822 cm21; dH
(400 MHz, CDCl3) 8.22 (1H, s, 3-H), 7.64 (AA0), 7.46
(BB0), 7.44 0(1H, dd, J¼16.0, 9.0 Hz, 20-H), 7.05 (1H, d,
J¼9.0 Hz, 3 -H), 6.58 (1H, d, J¼16.0 Hz, 10-H), 3.00 (6H, s,
N–CH3); dC (100 MHz, CDCl3) 153.2 (5-C), 137.3 (10-C),
133.6 (40-C), 133.7 (20-C), 132.3 (3-C), 131.7 (30-C), 129.8
(30, 50-C), 120.6 (20, 60-C), 117.2 (10-C), 113.3 (CuN), 92.4
(4-C), 42.4 (N–CH3). Anal. calcd for C15H14ClN5 (299.76),
C: 60.10, H: 4.71, N: 23.36; found C: 60.12, H: 4.64, N:
23.36.
4.4.6. 1-(4-Fluorophenyl)-3-[(1E)-3-oxoprop-1-en-1-yl]-
1H-pyrazole-4-carbonitrile (16b). 39.8 mg, 33%. Color-
less crystals (1408C, 22 h); mp 126–1298C (CH3CN); nmax
(KBr) 3123, 2234, 1678, 1513, 1374, 1248, 1224, 1161,
1128, 1065, 980, 833 cm21; dH (200 MHz, CDCl3) 9.79
(1H,0 d, J¼7.3 Hz, CHO), 8.31 (1H, s, 5-H), 7.66–7.73
(AA ), 07.54 (1H, d, J¼16.5 Hz, 10-H), 7.10–7.28 (3H, m,
BB0, 2 -H); dC (100 MHz, CDCl3) 193.2, 150.1, 139.0,
135.0, 133.9, 132.7, 122.2 (JC,F¼8.3 Hz), 117.1
(JC,F¼23.5 Hz), 112.5 (CuN), 94.8. Anal. calcd for
C13H8FN3O (241.22), C: 64.73, H: 3.34, N: 17.42; found
C: 64.56, H: 3.23, N: 17.15.