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Substitutions‐ und eliminierungsprozesse an 4,5‐dialkyl‐1,2,3‐thiadiazolen
Author(s) -
Meier Herbert,
Zimmer Oswald
Publication year - 1980
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570170763
Subject(s) - chemistry , thiadiazoles , halogenation , ring (chemistry) , side chain , closure (psychology) , nucleophile , stereochemistry , nucleophilic substitution , medicinal chemistry , organic chemistry , catalysis , economics , market economy , polymer
1,2,3‐Thiadiazoles are brominated in the α‐position of the side chain linked on C‐4 or C‐5. Several methods for the dehydrobromination are compared. Besides eliminations, nucleophilic substitutions can be observed. Regioselectivities are discussed concerning the ring closure in the generation of the 1,2,3‐thiadiazoles, the bromination and the S N ‐reactions. The most surprising result is the change of the positions of the substituents in the formation of 11b from 4b via an EA‐mechanism involving the intermediate 10b .