oxide (1.9 × 52 cm). Initially a mixture (8 mg) of pyrrolopyrimidine 3 with 3,5-dimethyl-2,6-diphenylpiperid-4-
one (Rf 0.63, ethyl acetate–hexane, 1:4) was eluted with hexane. A characteristic green spot, identical with a
standard spot, appeared on TLC [3]. Then 3,5-dimethyl-2,6-diphenylpiperid-4-one (0.11 g, 3.6%) was eluted;
white crystals, mp 128-130°C (hexane). A sample mixed with a standard melted with no depression of melting
point. A mixture of hexane–ethyl acetate, 30:1, eluted pyrrolopyridine 9 (75 mg, 2.5%); yellow crystals, mp 126-
128°C (ethyl acetate–hexane), Rf 0.64 (ethyl acetate–heptane, 1:3). Lit. data [1]: mp 128-131°C (hexane), Rf
0.63. Found, %: C 83.63; H 6.61; N 9.40. [M]+ 302. C21H22N2. Calculated, %: C 83.43; H 7.31; N 9.33. [M]+
302.
A more polar mixture of ethyl acetate–hexane, 1:10, eluted a single isomer of 4, yellow crystals;
mp 170-171°C (ethyl acetate–hexane), Rf 0.58 (Silufol, ethyl acetate–heptane, 1:3). Lit. data [3] for an isomer
with an axial–equatorial linkage of rings; mp 172-173°C (hexane), Rf 0.58 (Silufol, ethyl acetate–hexane, 1:3).
Found, %: N 8.34. [M-H2O]+ 328. C23H26N2O. Calculated, %: N 8.13. [M-H2O]+ 328. Three isomers of 4 were
eluted (75 mg, 2.5 %); white crystals, mp 136-145°C, Rf 0.53, 0.2, and 0.17 (Silufol, ethyl acetate–heptane, 1:3).
Their chromatographic mobility was identical to a standard sample [3]. Found, %: N 8.24. [M-H2O]+ 328.
C23H26N2O. Calculated, %: N 8.13. [M-H2O]+ 328. Finally a mixture of ethyl acetate–hexane, 1:4, eluted
dimethylhydroxysulfimide (80 mg); colorless crystals, mp 105-106°C (ethyl acetate–hexane). Found, %:
N 15.53. [M]+ 93. C2H7NOS. Calculated, %: N 15.05. [M]+ 93.
5,7-Dimethyl-4,6-diphenyl-4,5,6,7-tetrahydropyrrolo[1,2-c]pyrimidines (10) and 2-Ethynyl-7a-
hydroxy-3a,5,7-trimethyl-4,6-diphenylpyrrolo[3,2-c]pyridines (11). Acetylene was bubbled through a
solution of oxime 5 (5 g, 16 mmol) and RbOH (0.83 g, 8 mmol) in DMSO (50 ml) at 70°C. After 2 h, further
RbOH (0.4 g, 4 mmol) was added and the reaction conducted to the end (check by TLC). The mixture was
cooled, poured into ice water (150 ml) , extracted with ether (5 × 100 ml), and the extract dried over MgSO4.
After distilling off the ether a dark resinous mass (5.14 g) was obtained. Part of this residue (2.7 g) was
chromatographed on a column of aluminum oxide (1.9 × 50 cm). Initially a mixture of compounds 10a and 10b
(20 mg, 1.32%) was eluted with hexane. NMR spectrum of compound 10a (CDCl3), δ, ppm (J, Hz): 1.17 (3H, d,
3JCH = 6.7, 4-CH3); 1.75 (3H, s, N–CH3); 2.12 (3H, s, 5-CH3); 3.05 (1H, m, 4-H); 3.84 (1H, d, 3J34 = 3.7, 3-H);
3
3
3
4.95 (1H, s, 1-H); 5.78 (1H, d, J67 = 2.8, 6-H); 5.86 (1H, d, J67 = 2.8, 7-H); 7.30-7.45 (10H, m, 2-C2H5).
Pyrrolopyrimidine 10b (35 mg, 2.3%) was then eluted, white crystals of mp 111-112°C (hexane), Rf 0.7 (Silufol,
3
ethyl acetate–heptane, 1:2). NMR spectrum of 10b (CDCl3), δ, ppm (J, Hz): 1.17 (3H, d, JCH3 = 6.7, 4-CH3);
3
1.75 (3H, s, N-CH3); 2.12 (3H, s, 5-CH3); 3.15 (1H, d, J3,4 = 10.1, 3-H); 3.31 (1H, m, 4-H); 5.01 (1H, s, 1-H);
3
3
5.78 (1H, d, J67 = 2.8, 6-H); 5.86 (1H, d, J67 = 2.8, 7-H); 7.30-7.45 (10H, m, 2-C2H5). Mass spectrum, m/z
(Irel, %): 316 (92) [M]+, 315 (57), 302 (6), 301 (24), 288 (32), 287 (10), 286 (6), 285 (4), 240 (13), 239 (72), 224
(12), 223 (18), 210 (5), 209 (10), 208 (17), 198 (28), 197 (68), 196 (19), 194 (8), 183 (9), 182 (33), 180 (9), 167
(13), 129 (14), 128 (19), 120 (44), 119 (16), 188 (100), 116 (14), 115 (37), 91 (75), 89 (15), 82 (15), 77 (57), 65
(16), 51 (14), 42 (17). Found, %: N 8.98. C22H24N2. Calculated, %: N 8.85. At the end of the chromatography,
1,3,5-trimethyl-2,6-diphenylpiperid-4-one (40 mg) was isolated as white crystals; mp 105-106°C (heptane). A
mixing test with a standard sample gave no depression of melting point.
The reaction mixture was analyzed on the chromato-mass spectrometer. The formation of three isomers
of perhydropyrrolopyridine 11 was established. The mass spectra were characterized by the presence of a peak
for the [M-H2O]+ ion with m/z 342.
Oximes of 1-Benzyl-, 1-Benzyl-2-methyl-, and 1-Benzyl-4-methylpyrrolid-3-ones (5-7). A solution of
1-benzyl-, 1-benzyl-2-methyl-, or 1-benzyl-4-methylpyrrolid-3-ones (0.1 mol), obtained by Dieckmann
cyclization from (β-ethoxycarbonylethyl)-methoxycarbonylmethylbenzylamine, (α-ethoxycarbonylethyl)-β-
ethoxycarbonylethylbenzylamine, and (β-ethoxycarbonylpropyl)methoxycarbonylmethylbenzylamine respectively
[8], hydroxylamine hydrochloride (0.2 mol), and potassium hydroxide (0.3 mol) in ethanol (200 ml) was boiled
for 5-6 h (check by TLC). After distilling off the alcohol the residue was extracted with chloroform
332