A Reagent, Ethyl 2-(2-tert-Butyl-2H-tetrazol-5-yl)-3-(dimethylamino)acrylate (DMTE), for Facile Synthesis of 2, 3-(Ring Fused)-5-(5-tetratzolyl)-4H-pyrimidin-4-one Derivatives

Abstract

A method for synthesizing 2, 3-(ring fused)-5-(5-tetrazolyl)-4H-pyrimidin-4-one derivative from ethyl 2-(2-tert-butyl-2H-tetrazol-5-yl)-3-(dimethylamino)acrylate (DMTE) (4a) and amino-heterocycles is described. The structure of DMTE, which was prepared from ethyl (2-tert-butyl-2H-tetrazol-5-yl)acetate (3a) with dimethylformamide diethylacetal, was determined by X-ray analysis to be Z form. The reaction of 2-amino-5-methyloxazole (6) with DMTE in acetic acid gave the oxazolo[3, 2-a]pyrimidine derivative (8), heating of which in concentrated sulfuric acid afforded the desired tetrazole derivative (20). Pyrimido[2, 1-b]benzothiazole (21), pyrazolo[1, 5-a]pyrimidine (22 and 23) and [1, 2, 4]triazolo[1, 5-a]pyrimidine (24) derivatives were prepared in a similar manner.