Yield:24422-15-9 22.0 g (>98% wt)

Reaction Conditions:

with thionyl chloride in N,N-dimethyl-formamide;

Steps:

7 3,4,5-Trichloro-2-thiophenecarbonyl chloride

EXAMPLE 7 3,4,5-Trichloro-2-thiophenecarbonyl chloride A mixture of 20.4 g (0.088 mole) of 3,4,5-trichloro-2-thiophenecarboxylic acid, 7.3 mL (0.1 mole) of thionyl chloride, 0.2 mL of DMF and 80 mL of 1,2-dichloroethane was heated at reflux temperature for 3 h. The reaction mixture became a clear solution after 1 h of heating. The mixture was allowed to cool to RT, concentrated in vacuo and exposed to high vacuum to give 22.0 g (>98% wt) an oil which solidified upon standing to an off-white powder, mp 37°-41° C.

References:

US6096898,2000,A