3445-77-0Relevant academic research and scientific papers
COMPOSES SULFURES HETEROCYCLIQUES. XCIII (1). ACTION DU DIAZOACETATE D'ETHYLE ET DE DIAZOCETONES SUR LES THIOPYRANNETHIONES-2
Sauve, Jean-Pierre
, p. 582 - 587 (2007/10/02)
Ethyl diazoacetate reacts with 4,6-diarylthiopyran-2-thiones 1 giving diethyl α,α'-bis(4,6-diarylthiopyran-2-ylidene)-α,α'-dithioacetates 2 and traces of bis(thiopyran-2-ylidene) 3. We have never obtained the expected ethyl thiopyranylidene-acetate, but the disulfides 2, whose structures have been confirmed by NMR and IR spectra.With diazoacetone, in all cases, α-thiopyran-2-ylidene-acetone 4 is formed.According to the substituents of the thiopyran ring, the compounds 5, 6 and 7 are also obtained.Compounds 4, 5 and 6 are probably formed through a same thiiranne intermediate.Unsubstituted thiopyran-2-thione yields thiopyran-2-ylidene-acetone 4, the disulfide 6 and small quantities of thieno-1,2-dithiole-3-thione 7.With a large excess of diazoacetone, the reaction leads only to α-acetonylthio-α-thiopyranylidene-acetone 5. 3,5 Dialkylthiopyran-2-thiones only yield the corresponding thiopyranylideneacetone 4 whereas 4,6-diarylthiopyran-2-thiones give simultaneously all the compounds 3,4,5 and 6.With diazoacetophenone, α-(thiopyran-2-ylidene)acetophenone 8 is always the only product obtained, whatever the substituents of the thiopyran ring may be.
