Cyclohexanecarboxylic acid → 1-(2-Ethylbutyl)cyclohexanecarbonyl chloride

Participants

Reaction Conditions

Reaction Steps

A mixture of 103.0 mmol 1-(2-ethyl-butyl)-cyclohexanecarboxylic acid and 38.9 mmol cyclohexanecarboxylic acid was warmed to 50° C. 12.4 mL (170.3 mmol=1.2 Eq. relative to the sum of both acids) of thionyl chloride was added during 16 minutes at a temperature of 44-50° C. (reaction is endothermic) and the reaction mixture was kept at 52-53° C. After 1 hr the reaction was incomplete (5.2% 1-(2-ethyl-butyl)-cyclohexanecarboxylic acid and 13.8% 1-(2-ethyl-butyl)-cyclohexanecarboxylic acid anhydride), after 6 hrs still incomplete (1.9% 1-(2-ethyl-butyl)-cyclohexanecarboxylic acid and 2.8% 1-(2-ethyl-butyl)-cyclohexanecarboxylic acid anhydride). After addition of another 4.0 mL (55 mmol) thionylchloride and 3 hr at 52-53° C. the reaction was almost complete (0.18% 1-(2-ethyl-butyl)-cyclohexanecarboxylic acid and 0.47% 1-(2-ethyl-butyl)-cyclohexanecarboxylic acid anhydride). After removing volatile components in vacuo (60° C. bath, 3.3-3.7 mbar followed by 120° C. bath, 9.3-9.6 mbar) 20.21 g of residue was obtained (assay 96.6% 1-(2-ethyl-butyl)-cyclohexanecarbonyl chloride, yield 82.1%).

Provenance & Evidence