- New Syntheses with Elemental Sulfur. - Synthesis and Reactions of New 1,3,4-Thiadiazoles
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The one-step synthesis of 2,5-dialkyl-1,3,4-thiadiazoles 1 from aliphatic aldehydes, hydrazine hydrate and elemental sulfur is described.Chlorination of 1a yields 2,5-bis(trichloromethyl)-1,3,4-thiadiazole (2a).Reaction of 2a with methanol affords the orthoester 3, which forms with aromatic compounds a large number of new 2,5-disubstituted 1,3,4-thiadiazoles 5 - 7.Removal of one trichloromethyl group of 2a leads to 2-trichloromethyl-1,3,4-thiadiazole (10) which on halogenation gives the 2-halo-5-trichloromethyl-1,3,4-thiadiazoles 11.Reactions with nucleophilic compounds lead to the corresponding thiadiazoles 12 and 13.
- Hagen, Helmut,Kohler, Rolf-Dieter,Fleig, Helmut
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p. 1216 - 1231
(2007/10/02)
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