(hexane), Rf 0.71. IR spectrum: 3512 (OH), 1560 and 1385 cm-1 (NO2). Mass spectrum, m/z (Irel, %):
304 (2, M+), 286 (7), 244 (12), 190 (34), 130 (100), 115 (30), 103 (15), 91 (27), 77 (40). Found, %: C 67.4;
H 8.1; N 9.5. C17H24N2O3. Calculated, %: C 67.1; H 7.9; N 9.2.
1-Cyano-4,5-dihydro-5-methyl-3H-spiro(benz-2-azepine-3-cyclohexane] (6). A. A solution of
potassium cyanide (0.26 g, 4 mmol) in water (2 ml) was added gradually to a solution of nitrone 1 (0.5 g,
2 mmol) in THF (15 ml). The mixture was kept for a day at 20°C. After removal of the THF in vacuum, water
was added (50 ml) and the mixture was extracted with ether (4 × 20 ml). The extract was dried over magnesium
sulfate, the ether was evaporated, and the residue (0.43 g) was crystallized from hexane to give starting nitrone 1
(0.1 g, 20%). The mother liquor was chromatographed on silica gel to give compound 6 (0.15 g, 30%) as a
viscous light yellow oil, Rf 0.81. IR spectrum: 2230 (C=N), 1655 (C=N) cm-1. Mass spectrum, m/z (Irel, %):
252 (36, M+), 251 (18), 237 (30), 223 (23), 212 (14), 210 (27), 209 (21), 199 (22), 198 (51), 197 (36), 196 (14),
195 (20), 184 (19), 158 (14), 157 (31), 156 (100), 155 (82), 154 (33), 144 (36), 142 (36), 140 (62), 130 (30),
129 (83), 128 (71), 127 (41), 115 (79), 103 (29), 77 (41). Found, %: C 81.2; H 7.7; N 10.9. C17H20N2.
Calculated, %: C 81.0; H 7.9; N 11.1.
B. A solution of nitrone 1 (0.5 g, 2 mmol), potassium hydroxide (0.22 g, 4 mmol), DMSO (1.25 g,
16 mmol), and acetone cyanohydrin (0.51 g, 6 mmol) in ethanol (20 ml) was heated at 50°C for 1 h, then poured
into water (50 ml) and extracted with ether (3 × 20 ml). The residue (0.53 g) after evaporation of the ether was
chromatographed on a silica gel column (10 × 1 cm) to give compound 6 (0.42 g, 84%) identical in
chromatographic mobility and spectroscopic characteristics with a sample made by method A.
5-Methyl-1-phenyl-4,5-dihydro-3H-spiro[benz-2-azepine-3-cyclohexane] N-Oxide (7). A solution of
compound 2 (2.45 g, 7.6 mmol), sodium tungstate dihydrate (0.1 g, 0.3 mmol), and 30% hydrogen peroxide
(4.5 ml, 45.6 mmol) in acetone (10 ml) was boiled for 8 h (monitored by TLC). After evaporation of the
acetone, water (50 ml) was added to the residue and the mixture was extracted with chloroform. The extract was
washed with water and dried over magnesium sulfate. After removal of the chloroform, the residue was
crystallized from a mixture of hexane and ethyl acetate to give compound 7 (1.14 g, 55%) as white crystals;
mp 126-128°C, Rf 0.2. IR spectrum: 1493 (C=N), 1247 cm-1 (N O). Mass spectrum, m/z (Irel, %): 319 (32, M+),
→
318 (6), 302 (100), 287 (10), 277 (20), 260 (35), 224 (25), 208 (60), 207 (62), 206 (60), 199 (32), 191 (10),
190 (8), 178 (20), 165 (23), 131 (20), 130 (18), 129 (18), 128 (20), 115 (20), 103 (20), 91 (30), 77 (41).
Found, %: C 82.6; H 8.0; N 4.5. C22H25NO. Calculated, %: C 82.8; H 7.8; N 4.4.
1-Benzoyl-5-methyl-4,5-dihydro-3H-spiro[benz-2-azepine-3-cyclohexane] N-Oxide (8) was
obtained analogously to compound 7 from hydroxylamine 3 (0.5 g, 1.5 mmol). Compound 8 (0.41 g, 79%),
white crystals; mp 135-137°C, Rf 0.27. IR spectrum: 1666 (C=O), 1530 (C=N), 1247 cm-1 (N O). Mass
→
spectrum, m/z (Irel, %): 347 (18, M+), 330 (57), 315 (5), 305 (18), 288 (5), 276 (4), 242 (43), 236 (10), 235 (12),
234 (9), 226 (35), 225 (25), 224 (30), 131 (20), 130 (40), 129 (22), 116 (13), 115 (13), 105 (100), 95 (88),
78 (50), 77 (50). Found, %: C 79.4; H 7.2; N 4.1. C23H25NO2. Calculated, %: C 79.5; H 7.2; N 4.0.
1-Isopropyl-5-methyl-4,5-dihydro-3H-spiro[benz-2-azepine-3-cyclohexane] N-Oxide (9) was
obtained analogously to compound 8 from imine 4 (1.95 g, 6.8 mmol). Yield 1.14 g (59%), a viscous light
yellow which crystallized on prolonged standing; mp 68-70°C. IR spectrum: 1505 (C=N), 1230 cm-1 (N O).
→
Mass spectrum, m/z (Irel, %): 285 (55, M+), 284 (8), 268 (100), 253 (10), 252 (12), 243 (20), 242 (65), 226 (32),
199 (32), 190 (40), 174 (55), 173 (30), 172 (35), 161 (25), 160 (20), 158 (40), 157 (38), 146 (30), 144 (30),
143 (30), 131 (40), 130 (78), 129 (40), 128 (40), 115 (38), 103 (28), 91 (30), 77 (32), 43 (50). Found, %: C 79.6;
H 9.3; N 5.1. C19H27NO. Calculated, %: C 80.0; H 9.5; N 4.9.
1-Benzyl-5-methyl-4,5-dihydro-3H-spiro[benz-2-azepine-3-cyclohexane] N-Oxide (10). A solution
of hydroxylamine 3 (1.0 g, 3 mmol), 30% hydrogen peroxide (3 ml, 30 mmol), and sodium tungstate dihydrate
(40 mg, 0.12 mmol) in ethanol (15 ml) was boiled for 2 h. The ethanol was evaporated, water (50 ml) was
added, and the mixture was extracted with chloroform. The extract was dried over magnesium sulfate, the
chloroform was evaporated, and the residue was crystallized from a mixture of hexane and ethyl acetate to give
351