FORMATION OF IMIDAZOPYRIDINES BY THE PHASE-TRANSFER CATALYZED REACTION OF ALPHA-(AMINOMETHYL)PYRIDINES WITH CHCL3 AND ALKALINE HYDROXIDE

The reaction of chloroform with 2-(aminomethyl)pyridine (1) under basic phase-transfer catalysis affords the highly fluorescent imidazo[1,5-alpha]pyridine (2) in 25% isolated yield. Despite the formation of considerable tarry residue, GC-MS indicates that the volatile fraction of the reaction is simple and consists of 2 and two minor residue, GC-MS indicates that the volatile fraction of the reaction is simple and consists of 2 and two minor components identified as N-(2-pyridylmethyl)formamide (6) and (2-pyridylmethyl)isonitrile (7). The basic phase transfer catalyzed reaction of chloroform with a series of alpha-(aminomethyl)azanaphthalenes was found to be general and yield the corresponding annulated imidazo derivaties in comparable yields. Despite product yields in the 25% range, GC of the reaction mixtures indicates that the volatile fractions generally consist of residual starting aminomethyl compound, the imidazo product, and a minor amount of the (alpha-azanaphthylmethyl)formamide. However, 3-(aminomethyl)isoquinoline (18) failed to provide any of the expected imidazo[1,5-b]isoquinoline (19). The failure to detect 19 was investigated.