Prepn. of 5-methyl-7-di:ethyl-amino-S-triazolo (1,5-a) pyrimidine

摘要

The prepn. of 5-methyl-7-diethyl amino-s-triazolo-(1,5a) pyrimidine (I) comprises (a) chlorination of 5-methyl- -7-hydroxy -5-triazolo (1,5a) pyrimidine (II) by continuously mixing it with phosphorus oxychloride (III) and heating the mixt. to the boiling point of (IV) using intensive indirect heating and then reacting (II) and (III) to completion by successive addition and removal of heat to maintain constant boiling of (III); (b) amination of the intermediate 5-methyl-7-chloro -5-triazolo (1,5a) pyrimidine (IV); (c) liberation of free (I) from (I)-hydrochloride; (d) phase sepn; (e) distillative removal of excess diethylamine and the toluene used in phase sepn. All steps, including the conventional steps (b)-(e) are carried out continuously.