Methyl chloroformate → HCID 54063869, compound

Participants

Reaction Conditions

Reaction Steps

3.8 g (10 mmol) of 5-chloro-6-(4-chlorophenyl)-4-hydroxy-3-(2,4,6-trimethylphenyl)-2-pyrone (Example I-a-1) are initially charged in 25 ml of ethyl acetate. At 20° C., 1.0 g (10 mmol) of triethylamine are added and a solution of 0.95 g (10 mmol) of methyl chloroformate in 10 ml of ethyl acetate is added dropwise at 0° C. The mixture is subsequently stirred at 20° C. for 20 h. Precipitated triethylamine hydrochloride is filtered off with suction and washed with ethyl acetate. The combined mother liquors are washed twice with 50 ml of half-concentrated sodium chloride solution each time, dried over magnesium sulphate and concentrated under reduced pressure. 4.0 g (92.4% of theory) of crude 5-chloro-6-(4-chlorophenyl)-4-methoxycarbonyloxy-(2,4,6-trimethylphenyl)-2-pyrone are obtained. Recrystallization from 50 ml of cyclohexane affords 3.1 g (72% of theory) of pure product which melts at 136-138° C.

Provenance & Evidence