Azaindole derivatives. 66. 1,6-disubstituted 4-methyl-5-cyano-7-azaindolines
A general method was developed for the synthesis of 1,6-disubstituted 4-methyl-5-cyano-7-azalndolines from the readily available ammonium salt of 2,6-dihydroxy-3-(β-hydroxyethyl)-4-methyl-5-cyanopyridine through the corresponding N-substituted ammonium salts and N-substituted 2-amino-3-(β-hydroxyethyl)-4-methyl-5-cyano-6-hydroxypyridines with treatment of the latter by POCl3. This method gives a 40% yield of 4-methyl-5-cyano-7-azaindoline compounds containing various aralkyl or alkyl substituents at N-1 and a hydroxy group or halogen atom at C-6 in three steps.