DERIVATIVES OF AZYINDOLES. 65. SYNTHESIS OF 1-BENZYL-4-METHYL-5-CYANO-6-HYDROXY-7-AZAINDOLINE

Article abstract of DOI:10.1007/BF00513579

Treatment of the ammonium (I) or benzylammonium salt of 2,6-dihydroxy-3-(β-hydroxyethyl)-4-methyl-5-cyanopyridine (II) with a mixture of benzylamine and phosphorus pentoxide yielded 2-benzylamino-3-(β-hydroxyethyl)-4-methyl-5-cyano -6-hydroxypyridine (III), which, when heated with phosphorus oxychloride, is converted to 1-benzyl-4-methyl-5-cyano-6-hydroxy-7-azaindoline (IV).The products of thermal fragmentation of II with benzylamine were studied by the method of chromato-mass spectrometry.In addition to compound III, N,N'-dibenzylurea (V) and the dibenzylamide of malonic acid (VI) were preparatively isolated from the reaction products .The cyclization of I and II to 4-methyl-6-hydroxy-2,3-dihydro-7-azabenzofuran (VII) and 4-methyl-5-cyano-6-hydroxy-2,3-dihydro-7-azabenzofuran (VIII) was carried out.Heating VIII with benzylamine at 200-210 grad C led to compound III.