A new method for the regioselective synthesis of 1-aryl-5-amino-1H-tetrazoles has been developed by the reaction of arylcyanamides with sodium azide using ZnCl2 under ultrasound irradiation in excellent yields.
A general synthetic method for the formation of arylaminotetrazoles using natural natrolite zeolite as a new and reusable heterogeneous catalyst
An efficient method for preparation of arylaminotetrazoles is reported using natrolite zeolite as a natural catalyst. Generally, isomer of 5-arylamino-1H-tetrazole can be obtained from arylcyanamides carrying electron-withdrawing substituent on aryl ring and as the electropositivity of substituent is increased, the product is shifted toward the isomer of 1-aryl-5-amino-1H-tetrazole. This method has the advantages of high yields, simple methodology, short reaction times and easy work-up. The catalyst can be recovered by simple filtration and reused in good yields. (C) 2009 Elsevier Ltd. All rights reserved.
Synthesis of arylaminotetrazoles by ZnCl2/AlCl3/silica as an efficient heterogeneous catalyst
作者:Davood Habibi、Mahmoud Nasrollahzadeh
DOI:10.1007/s00706-011-0670-8
日期:2012.6
Arylaminotetrazoles were efficiently synthesized from secondary arylcyanamides by application of ZnCl2/AlCl3/silica as a reusable heterogeneous Lewis acid catalyst. 5-Arylamino-1-tetrazoles can be obtained from arylcyanamides carrying electron-withdrawing substituents on the aryl ring, while with electron-releasing groups 1-aryl-5-amino-1-tetrazoles will be produced. The former isomer is also produced within longer reaction times (similar to 20 h) even with electron-releasing groups.