Thionyl Chloride → P-ethyl-2-nitro-5-(2-chloro-4-trifluoromethylphenoxy)phenylphosphinic acid chloride

Participants

Reaction Steps

A mixture of methyl P-ethyl-2-nitro-5-(2-chloro-4-trifluoromethylphenoxy)phenylphosphinate (700 mg, 1.65 mmol) and thionyl chloride (5 ml) is heated under reflux for 2 hours. The reaction mixture is concentrated to dryness to give P-ethyl-2-nitro-5-(2-chloro-4-trifluoromethylphenoxy)phenylphosphinic chloride. To a solution of the phosphinic chloride in methylene chloride (8 ml) is added methyl 2-hydroxyimino-3-methylbutanoate (320 mg, 2.48 mmol) in one portion. The mixture is stirred at RT for 3 hours. The reaction is then worked up in methylene chloride, washed, dried, evaporated to dryness and purified by prep. TLC to yield methyl 2-[P-ethyl-2-nitro-5-(2-chloro-4-trifluoromethylphenoxy)phenylphosphinyloxyimino]-3-methylbutanoate.

Provenance & Evidence