128080-75-1

Upstream product

• 148915-44-0 2-(4-Bromobenzoyl)-3,6-dihydro-4,5-dimethyl-2H-thiopyran 1-oxide 
• 128080-67-1 2-(4-Bromobenzoyl)-3,6-dihydro-4,5-dimethyl-2H-thiopyran 
• 91929-74-7 Sodium S-4-bromophenacyl thiosulfate 
• 513-81-5 2,3-dimethyl-buta-1,3-diene 

Relevant academic research and scientific papers

Synthesis and thermal transformation of stable monocyclic λ4-thiabenzenes

The stable monocyclic λ4-thiabenzenes 6a-e, which are stabilized with electron-withdrawing substituents such as benzoyl, cyano and alkoxycarbonyl groups, are synthesized in high yields by proton abstraction from the corresponding thiopyranium salts 5a-e with triethylamine in ethanol. The ylidic properties of the λ4-thiabenzenes are established based on spectral and chemical evidence. Thermal decomposition of the λ4-thiabenzenes affords alkyl-rearranged products 7,8, and 9, thienofuran derivatives 10 (from benzoyl-substituted λ4-thiabenzenes), and thiophene derivatives 11. A plausible mechanism for the formation of those products is also discussed.

First isolation of monocyclic thiabenzenes

Monocyclic thiabenzenes, 1-alkyl-2-aroyl- (or 1-alkyl-2-cyano-) 4,5-dimethyl-thiabenzenes (6) are successfully synthesized by deprotonation of the corresponding thiopyranium salts (5) with triethylamine in ethanol. The ylide structures of 6 are elucidated by spectral and chemical evidence. Thermal reaction of 6 in several solvents provides S-alkyl rearranged products and ring-contracted ones, depending upon solvents used.