| Abstract: | Tetrazole Compounds. 2. 1-Aryl-1H-tetrazole-5-acetaldehyde Derivatives from 1-Aryl-5-(2-dimethylamino-vinyl)-1H-tetrazoles 1-Aryl-5-(2-dialkylamino-vinyl)-1H-tetrazoles 2 , easily accessible by the reaction of 3-chloro-propeniminium salts 1 with excess sodium azide in refluxing alcohols, represent enamines of the hitherto unknown 1-aryl-1H-tetrazole-5-acetaldehydes 3 . Attempts to isolate the latter after acid-catalyzed hydrolysis of 2 were unsuccessful. However, generated in situ, they can be trapped by suitable aldehyde reagents. Thus, starting from 1-aryl-5-(2-dimethylamino-vinyl)-1H-tetrazoles 4 , the 4-nitrophenylhydrazones 5a--hyphen;i , 2,4-dinitrophenylhydrazones 5j--hyphen;r , and thiosemicarbazones 6 of the corresponding 1-aryl-1H-tetrazole-5-acetaldehydes 3 were obtained. Analogously, acid-catalyzed hydrolysis of 4 in the presence of 1,2-dianilinoethane resulted in 1-aryl-5-(1,3-diphenyl-2-imidazolidinylmethyl)-1H-tetrazoles 7 . --hyphen; The structure of the aldehyde derivatives 5 , 6 , and 7 was proved by 1H n.m.r. spectroscopy. |
