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Synthese von 1, 3, 4‐Oxadiazolen und 4, 5‐Dihydro‐1, 2, 4‐triazinen aus 3‐Dimethylamino‐2, 2‐dimethyl‐2 H ‐azirin und Carbohydraziden
Author(s) -
Link Helmut
Publication year - 1978
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19780610714
Subject(s) - azirine , chemistry , medicinal chemistry , stereochemistry , organic chemistry , ring (chemistry)
Synthesis of 1,3,4‐Oxadiazoles and 4,5‐Dihydro‐l,2,4‐triazines from 3‐Dimethylamino‐2,2‐dimethyl‐2 H azirine and Carbohydrazides 3‐Dimethylamino‐2, 2‐dimethyl‐2 H ‐azirine ( 1 ) reacts with aromatic carbohydrazides to give 2‐(1‐amino‐1‐methylethyl)‐5‐aryl‐1, 3, 4‐oxadiazoles ( 7 , 10 , 11 ). With ethyl carbazate the azirine 1 forms the aminoester 15 , which is easily cyclized to the 4, 5‐dihydro‐1, 2, 4‐triazin‐3 (2 H )‐one 16 . From the reaction of 1 with oxamohydrazide ( 17 ) and oxalodihydrazide 19 the 4, 5‐dihydro‐1, 2, 4‐triazin‐3‐carboxamide 18 and the symmetric compound 20 , respectively, have been isolated. Reactions supporting the structures of the new compounds are described.