Phosphorylation of 1-alkylmidazoles and 1-alkylbenzimidazoles with phosphorus(III) halides in the presence of bases

Phosphorylation of I-alkyl substituted imidazoles and benzimidazoles with P (III) halides in pyridine was shown to proceed at the 3-N atom of the heter oaryl ring and was followed by triethylamine-induced migration of the phosp horus group to the 2-C atom. Preparative methods were developed for the syn thesis of a range of 2-phosphorylated derivatives of the indicated imidazol es. The latter were found to undergo alkylation either at P(III) or 3-N cen ters, depending on the alkylating agent. (C) 1999 John Wiley & Sons, Inc.