2-Hydroxy-3, 4, 5-trichlorothiophene (4), 3-hydroxy-4-bromo-2, 5-dichlorothiophene (5) and 3-hydroxy-2, 4, 5-trichlorothiophene (6) have been synthesised. It was found that 4 exists in a carbonyl form, whereas in 5 and 6 the hydroxy forms were the major tautomers. Several derivatives of the trihalogenated hydroxythiophenes were prepared. O-Methylation was carried out with diazomethane and O-acetylation with acetyl chloride. Silylation of 4 was ...
