The synthesis of certain 5-aminotetrazole derivatives. II. The action of hydrazoic acid on monoalkylcyanamides

Abstract

In a previous communication the formation of 5-dialkylaminotetrazoles by the interaction of dialkylcyanamides and hydrazoic acid vas described (1). Since Hantzsch and Vagt had shown that cyanamide and hydrazoic acid react readily to form 5-aminotetrazole ( 2 ) , it was of interest to investigate the behavior of the monosubstituted cyanamides toward hydrazoic acid.1 Based on a thesis submitted to the School of Graduate Studies a t Michigan State College in 1952 by William L. Garbrecht in partial fulfillment of the requirements for the degree of Doctor of Philosophy.

Synthesis of arylaminotetrazoles by ZnCl2/AlCl3/silica as an efficient heterogeneous catalyst

“…The products were completely regiospecific. This observation is in contrast with those reports that the other reagents will often produce a mixture of isomers (Scheme 2) [7,19].…”

“…In other words, in the synthesis of aminotetrazoles from cyanamides, only 1-aryl-5-amino-1H-tetrazole 4 or a mixture of isomers 3 ? 4 was obtained [7,19]. Due to presence of the two CN groups, 1k (Table 1, entry 11) interestingly afforded the double-addition product.…”

“…Aminotetrazoles are conventionally synthesized by diazotation of aminoguanidine derivatives [6] or azidation of cyanamides [7,8], carbodiimides [9], thioureas [10,11], aminoiminomethanesulfonic acids [12], and benzotriazol-1-ylcarboximidamides [13]. 5-Amino groups can also be introduced into the tetrazole ring by nucleophilic substitution of the tetrazoles containing leaving groups in 5-position with the appropriate amines [14].…”

“…These methods have disadvantages such as production of a mixture of isomers, i.e., 5-arylamino-1H-tetrazoles 3 and 1-aryl-5-amino-1H-tetrazoles 4 [7], application of hydrazoic acid, low yield, long reaction times, harsh reaction conditions, difficulty of work-up due to the application of homogeneous catalyst, use of expensive and toxic reagents, and in situ generation of hydrazoic acid.…”

Biological Activity of Tetrazole Analogues of Indole-3-Acetic Acid and 2,4-Dichlorophenoxyacetic Acid

“…Aln extensive progranm of synthesis and testing oI tetrazoles has been conducted by Herbst and associates (2,3,5,7,15). Tetrazoles substituted only in the ring carbon (R-CN4H) are acids having one dissociable hydrogen.…”