Phosphorylation of 1-alkyl substituted imidazoles and benzimidazoles with P(III) halides in pyridine was shown to proceed at the 3-N atom of the heteroaryl ring and was followed by triethylamine-induced migration of the phosphorus group to the 2-C atom. Preparative methods were developed for the synthesis of a range of 2-phosphorylated derivatives of the indicated imidazoles. The latter were found to undergo alkylation either at P(III) or 3-N centers, depending on the alkylating agent.

Phosphorylated Azoles. Part 2. Phosphorylation of 1-Alkylimidazoles and 1-Alkylbenzimidazoles with Phosphorus(III) Halides in the Presence of Bases. -The phosphorylation of 1-alkylimidazoles [cf. (I)] as well as related benzimidazoles with P(III) halides in pyridine proceeds at the 3-N atom of the heteroaryl ring [→(III)] and is followed by a triethylamine-induced migration of the phosphorus group to the 2-C atom. Preparative methods are developed which lead to a wide range of 2-phosphorylated derivatives of the indicated imidazoles. -(TOLMACHEV, ANDREJ A.; YURCHENKO, ALEKSANDR A.; MERCULOV, ANATOLIJ S.; SEMENOVA, MARINA G.; ZARUDNITSKII, EVGENIJ V.; IVANOV, VLADIMIR V.; PINCHUK, ALEKSANDR M.; Heteroat. Chem. 10 (1999) 7, 585-597; Inst. Org. Chem., Acad. Sci. Ukr., Kiev 253660, Ukraine; EN)