Hydrochloric Acid → HCID 18551169, compound

Participants

Reaction Conditions

Reaction Steps

4.2 ml of a 0.6 m solution of 3-methoxyphenylmagnesium bromide in tetrahydrofuran is mixed at −70° C. with 257 mg of copper bromide-dimethylsulfide complex and then stirred at −40° C. for 20 minutes. It is cooled again to −70° C., and 0.33 ml of 1,3-dimethyl-tetrahydro-2-1H-pyrimidinone and a mixture of 400 mg of 4-methyl-2-oxo-3-pentenoic acid methyl ester (Liebigs Annalen [Liebigs Annals] 1974, 477) and 0.71 ml of trimethylchlorosilane in 3.5 ml of tetrahydrofuran are slowly added. It is stirred for one hour at −70° C. and then heated to room temperature. Then, 2N hydrochloric acid and ethyl acetate are added, the ethyl acetate phase is separated, it is concentrated by evaporation, and the residue is dissolved in 5 ml of dichloromethane. After 200 mg of tetrabutylammonium fluoride is added, it is left at room temperature for one hour, then washed with water, and the dichloromethane phase is dried (Na2SO4) and concentrated by evaporation. After chroma-tography on silica gel with hexane/ethyl acetate (97:3), 63 mg of 4-(3-methoxyphenyl)-4-methyl-2-oxo-valeric acid-methyl ester, which is mixed with 1 ml of potassium hydroxide in methanol (10%), is obtained. After 45 minutes, it is concentrated by evaporation, the residue is dissolved in water and extracted with diethyl ether. The aqueous phase is then acidified with 6N hydrochloric acid and extracted with diethyl ether. The diethyl ether phase is dried (Na2SO4) and concen-trated by evaporation. 50 mg of 4-(3-methoxyphenyl)-4-methyl-2-oxo-valeric acid is obtained.

Provenance & Evidence