G. Kaupp et al.
FULL PAPER
1-(4-Bromophenyl)-3,3-diphenyltriazene (11 h): Yield: 350 mg (99%);
m.p. 48 498C (Ref. [32]: 508C); IR (KBr): nÄ 1597, 1503, 1483, 1459,
by 24 h ultrasound application in a test tube. The solid products were
neutralised with 0.5n NaOH (20 mL), washed with water and dried.
1418, 1394 (N N), 1243, 1198, 1171, 1091, 1009, 823 cmÀ1; MS (CI,
5-(4-Bromophenylhydrazono)hexahydropyrimidine-2,4,6-trione
(18a):
isobutane): m/z: 354 (100%), 352 (100%, [MH] ).
Yield: 155 mg (100%); m.p. 310 3128C; IR (KBr): nÄ 1754, 1707, 1657
1-(4-Carboxyphenyl)-3-(4-chlorophenyl)triazene (13g): Yield: 270 mg
(C O), 1585, 1511, 1490, 1436, 1403, 1385, 1351, 1260, 1174, 1076, 1010, 830,
819, 776, 754 cmÀ1; UV (CH3OH): lmax (e) 388 (26700) nm; 1H NMR
(CDCl3/[D6]DMSO): d 10.75 (bp, 2NH), 8.0 (s, 1NH), 7.48 (AA'BB',
2H), 7.42 (BB'AA', 2H); 13C NMR (CF3COOD): d 164.94, 164.35,
152.43, 139.35, 133.94 (2C), 125.27, 120.16 (2C), 116.35; MS (70 eV): m/z
(%): 312 (19), 310 (21), 171 (9), 169 (10), 157 (9), 155 (18).
(99%); m.p. 187 1888C (ref. [15]: 1888C); IR (KBr): nÄ 1690 (C O),
1608, 1560, 1542, 1494, 1386 (N N), 1307, 1290, 1207, 1163, 1116, 1095, 1044,
1017, 822 cmÀ1; 1H NMR (CDCl3/[D6]DMSO): d 9.6 9.0 (1NH), 8.0 7.2
(m, 8H); MS (CI, isobutane): m/z: 275 [M1] ; MS (EI): m/z (%): 237 (2),
149 (2), 137 (100), 127 (40), 120 (79).
1-(4-Carboxyphenyl)-3-(4-tolyl)triazene (13i): Yield: 250 mg (99%); m.p.
5-(4-Bromophenylhydrazono)-1,3-dimethylhexahydropyrimidine-2,4,6-tri-
one (18b): Yield: 167 mg (99%); m.p. 246 2488C; IR (KBr): nÄ 1719,
181 1848C (ref. [15]: 1838C); IR (KBr): nÄ 1677 (C O), 1605, 1556, 1504,
À1
1H NMR
1437, 1400 (N N), 1385, 1311, 1256, 1208, 1164, 848, 821 cm
;
1672, 1640 (C O), 1583, 1504, 1444, 1384, 1363, 1274, 1254, 1225, 1197, 1071,
1
809, 751 cmÀ1; UV (CH3OH): lmax (e) 390 (28800) nm; H NMR (CDCl3/
(CDCl3/[D6]DMSO): d 9.8 9.0 (1NH), 8.0 7.1 (m, 8H), 2.20 (s, 3H).
1-[1-(9,10-Anthraquinone)-yl)-3-(4-tolyl)triazene (13j): Yield: 339 mg
[D6]DMSO): d 7.55 (AA'BB', 2H), 7.40 (BB'AA', 2H), 3.29 (s, 3H), 3.26
(sh, 1NH), 3.25 (s, 3H); 13C NMR (CF3COOD): d 164.06, 162.9, 152.93,
139.79, 133.73 (2C), 123.51, 119.82 (2C), 115.89, 29.14, 27.77; MS (70 eV):
m/z (%): 340 (15), 338 (21), 183 (10), 173 (70), 171 (94), 157 (7), 155 (8);
HR-MS (CI, isobutane) calcd for C12H11BrN4O3H: 339.0140; found
339.0145.
(99%); m.p. 2158C (ref. [16]: 220 2248C); IR (KBr): nÄ 1667 (C O),
1640 (C O), 1590 , 1544, 1514, 1491, 1461, 1449, 1407 (N N), 1353, 1306,
1278, 1185, 1167, 1132, 1069, 1011, 926, 825, 810, 734, 709 cmÀ1; MS (CI,
isobutane): m/z: 342 [MH] .
1,2-Naphthoquinone-1-(4-nitrophenyl)hydrazone
(15a):
b-Naphthol
5-(4-Bromophenylhydrazono)-1,3-diethylhexahydropyrimidine-2,4,6-tri-
one (18c): Yield: 182 mg (99%); m.p. 1828C; IR (KBr): nÄ 1721, 1650
(173 mg, 1.20 mmol) and 4-nitrophenyldiazonium tetrafluoroborate (4a')
(237 mg, Aldrich, 97% purity, 1.00 mmol) were co-ground in an agate
mortar six times for 5 min. After being left to rest for 24 h, the mixture was
exposed to ultrasound for 24 h. The azo dye tetrafluoroborate was
neutralised and excess b-naphthol removed by washing with 0.5n NaOH
(20 mL) and water (20 mL). After drying, pure 15a (288 mg, 100%) was
(C O), 1585, 1519, 1438, 1410, 1383, 1281, 1237, 1104, 1082, 1071, 956,
824 cmÀ1; UV (CH3OH): lmax (e) 390 (28600) nm; 1H NMR (CDCl3/
[D6]DMSO): d 14.59 (s, 1NH), 7.55 (AA'BB', 2H), 7.44 (BB'AA', 2H),
4.06 (q, J 7.0 Hz, 2H), 4.02 (q, J 7.0 Hz, 2H), 1.28 (t, J 7.0 Hz, 3H);
1.27 (t, J 7.0 Hz, 3H); 13C NMR (CDCl3/[D6]DMSO): d 160.65, 158.38,
149.48, 139.79, 132.56 (2C), 119.86, 118.37 (2C), 116.87, 37.04, 36.19, 13.02
(2C); MS (70 eV): m/z (%): 368 (72), 366 (65), 340 (3), 338 (3), 219 (19), 198
(26), 196 (84), 173 (48), 172 (22), 171 (74), 170 (20), 169 (24), 157 (24), 155
(24), 145 (13), 143 (10), 125 (25); HR-MS (CI, isobutane) calcd for
C14H15BrN4O3H: 367.0405; found 367.0405.
obtained; m.p. 2488C (ref. [33]: 2498C); IR (KBr): nÄ 1622 (C O), 1592,
1500 (NO2), 1454, 1330 (NO2), 1258, 1226, 1201, 1152, 1106, 1034, 1011, 859,
1
836, 748 cmÀ1; H NMR (CF3COOD): d 8.69 (d, 1H), 8.60 (d, 2H), 8.21
(d, 1H), 8.07 (d, 2H), 7.82 (m, 2H), 7.70 (t, 1H), 7.17 (d, 1H).
1,2-Naphthoquinone-1-(phenyl)hydrazone (15d): b-Naphthol (77 mg,
0.60 mmol) and phenyldiazonium nitrate (84 mg, 0.50 mmol) were sepa-
rately ground in an agate mortar, cautiously mixed in a test tube that was
stoppered and after 24 h rest exposed to ultrasound for 24 h. The azo dye
nitrate was neutralised and excess b-naphthol removed by washing with
0.5n NaOH (20 mL) and water (20 mL). Pure 15d (121 mg, 98%) was
5-(4-Bromophenylhydrazono)-1,3-diphenyl-hexahydropyrimidine-2,4,6-
trione (18d): Yield: 228 mg (99%); m.p. 1508C; IR (KBr): nÄ 1691, 1655
(C O), 1517, 1490, 1429, 1404, 1384, 1358, 1294, 1233, 1071, 1005, 943, 825,
741, 693 cmÀ1; UV (CH3OH): lmax (e) 390 (18700) nm; 1H NMR (CDCl3/
[D6]DMSO): d 7.56 7.28 (m, 14H); 4.02 (s, 1NH); MS (70 eV): m/z (%):
464 (24), 462 (26), 198 (10), 196 (14), 171 (24), 169 (20), 120 (16), 119 (100);
HR-MS (CI, isobutane) calcd for C22H15BrN4O3H: 463.0627; found
463.0649.
obtained; m.p. 1328C (ref. [34]: 132 1338C); IR (KBr): nÄ 1619 (C O;
BLYP: 1607), 1598, 1550(C O; BLYP: 1560), 1500 (C N; BLYP: 1493),
À
1449, 1385 (C N; BLYP: 1373), 1268 (N N; BLYP: 1271), 1255, 1208, 1145,
839, 751 cmÀ1; 1H NMR (CDCl3): d 8.55 (d, 1H), 7.70 (m, 3H), 7.60 7.25
(m, 6H), 6.87 (d, 1H).
5-(4-Bromophenylhydrazono)-1,3-diethyl-2-thioxohexahydropyrimidine-
4,6-dione (18e): Yield: 189 mg (99%); m.p. 235 2378C; IR (KBr): nÄ
1,2-Naphthoquinone-1-(4-chlorophenyl)hydrazone (15g): b-Naphthol
(77 mg, 0.60 mmol) and 4-chlorophenyldiazonium nitrate hydrate[1]
(110 mg, 0.50 mmol) were separately ground in an agate mortar, cautiously
mixed in a closed test tube and after 24 h rest exposed to ultrasound for
24 h. The azo dye nitrate was neutralised and excess b-naphthol removed
by washing with 0.5n NaOH (20 mL) and water (20 mL). Pure 15g
(141 mg, 99%) was obtained; m.p. 161.58C (ref. [35]: 160 1618C); IR
1696, 1638 (C O), 1584, 1516, 1505, 1433, 1405, 1350, 1320, 1303, 1268, 1237,
1104, 1083, 1068, 911, 831 cmÀ1; UV (CH3OH): lmax (e) 417 (29600) nm;
1H NMR (CDCl3): d 14.83 (s, 1NH), 7.56 (AA'BB', 2H), 7.46 (BB'AA',
2H), 4.59 (q, J 7.0 Hz, 2H), 4.55 (q, J 7.0 Hz, 2H), 1.32 (t, J 7.0 Hz,
6H); 13C NMR (CDCl3): d 177.46, 159.31, 157.44, 139.77, 132.91 (2C),
120.83, 118.88 (2C), 117.97; 43.82, 42.65, 12.33, 12.12; MS (70 eV): m/z (%):
385 (10), 384 (42), 383 (8), 382 (37), 351 (31), 349 (37), 213 (13), 212 (100),
185 (12), 184 (10), 183 (15), 173 (24), 172 (28), 171 (38), 157 (18), 155 (25),
145 (8), 143 (12); HR-MS (CI, isobutane) calcd for C14H15BrN4O2SH:
383.0161; found 383.0159.
(KBr): nÄ 1621 (C O; BLYP:1607), 1603, 1563 (C O; BLYP: 1568; 1552),
1484 (C N; BLYP: 1493), 1450, 1412, 1388 (C N; BLYP: 1385), 1253, 1210,
1089 (C Cl; BLYP: 1062), 1006, 985, 821, 749, 680, 497 cmÀ1 1H NMR
;
(CDCl3): d 8.59 (d, 1H), 7.80 7.40 (m, 8H), 6.89 (d, 1H); MS (CI,
isobutane): m/z: 285 (35%), 283 (100%, [MH] .
Solid-state synthesis of 4-(arylhydrazono)-4,5-dihydropyrazole-5-ones 21:
3-Methyl-1-phenyl-4,5-dihydropyrazole-5-one (19, 1.00 mmol) and the
solid diazonium salt 4a', 4 f, 4 h or 6a (1.00 mmol) were cautiously co-
ground in an agate mortar for 5 min. The mixture was transferred to a
100 mL flask which was then evacuated. The mixture was exposed to
(CH3)3N (0.5 bar) for 12 h at room temperature. After condensation of
excess gas into a remote trap at 77 K, the trimethylammonium nitrate
(tetrafluoroborate) was washed away with water (ꢀ20 mL) and the
residual solid dried. The 13C NMR spectra of 21a,f,h have already been
reported in Ref. [36].
1,2-Naphthoquinone-1-(4-bromophenyl)hydrazone (15 h): b-Naphthol
77 mg (0.60 mmol) and MgSO4 ¥ 2H2O (60 mg, 0.50 mmol) as a drying
agent were finely ground in an agate mortar. 4-Bromobenzenediazonium
nitrate hydrate[1] (132 mg, 0.50 mmol) was added in five portions and co-
ground for 5 min each. The reaction was completed by 12 h exposure to
ultrasound, when all of the diazonium band had disappeared in the IR. The
solid material was washed with 0.5n NaOH (20 mL) and water (20 mL) to
yield 15 h (163 mg, 99%). M.p. 1718C (ref. [22]: 172 1738C); IR (KBr):
nÄ 1620 (C O), 1558, 1505, 821 cmÀ1; 1H NMR (CDCl3): d 8.50 (d, 1H),
7.71 (d, 1H), 7.59 (m, 6H), 7.40 (t, 1H), 7.86 (d, 1H); MS (CI, isobutane):
4-(4-Nitrophenylhydrazono)-3-methyl-1-phenyl-4,5-dihydropyrazole-5-
one (21a): Yield from 4a': 317 mg (98%); from 6a: 320 mg (99%); m.p.
m/z: 329 (95%), 327 (100%, [MH] ).
Solid-state preparation of 5-(4-bromophenylhydrazono)hexahydropyrimi-
dine-2,4,6-triones (18a d) and -4,6-dione-2-thione (18e): The barbituric
acid derivative 16 (0.50 mmol) was ground in an agate mortar. 4-Bromo-
benzenediazonium nitrate hydrate (4 h, 0.50 mmol) was added and co-
ground in five portions for 5 min, each. Most of the diazonium band at nÄ
2280 cmÀ1 had disappeared, but completion of the reactions was achieved
1978C (ref. [24]: 197 1988C); IR (KBr): nÄ 1666 (C O), 1610, 1599, 1558
À1
(C C, C N), 1505 (NO2), 1342 (NO2) cm
;
1H NMR (CDCl3): d 13.65
(1NH), 8.30 (AA'BB', 2H), 7.98 (BB'AA', 2H), 7.59 7.40 (m, 4H), 7.28 (m,
1H), 2.39 (s, 3H); 13C NMR (CDCl3/[D6]DMSO): d 155.61, 147.51,
145.49, 143.02, 136.59, 130.09, 127.74 (2C), 124.37 (2C), 124.12, 117.11 (2C),
114.70 (2C), 10.64.
1404
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Chem. Eur. J. 2002, 8, No. 6