Hydrochloric Acid → ethyl 3-hydroxy-3-methylcaproate

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Reaction Conditions

Reaction Steps

At room temperature, a three-necked flask fitted with reflux condenser, internal thermometer, dropping funnel and stirrer was charged, under nitrogen protective gas, with 11.2 g of zinc powder (170 mmol) in 65 ml of isopropyl acetate. After 3.2 ml of trimethylchlorosilane (25 mmol) had been added, the mixture was heated at 65° C. for 30 min, then left to cool to 60° C., following which 9.7 g of neat pentan-2-one (113 mmol) were added and then, over the course of 8 min, 22.6 g of neat ethyl bromoacetate (136 mmol) were added dropwise, the temperature being maintained at 60° C. by external cooling. The mixture was then stirred for 25 min at 60° C., and following cooling to 0° C., was acidified with 65 ml of 2 N hydrochloric acid to a pH of 1 and stirred for 30 min. Excess zinc was removed by filtration, and the organic phase separated. The organic phase was stirred at 0° C. with 60 ml of 1 N hydrochloric acid and then washed with 30 ml of saturated sodium hydrogen carbonate solution. Following phase separation and drying over sodium sulfate, the solvent was removed by distillation under reduced pressure. The isopropyl acetate solvent was recovered to an extent of greater than 90%). Distillation gave ethyl 3-hydroxy-3-methylcaproate in a yield of 18.2 g (93% of theory) with a boiling point of 41° C. (0.31 mbar).

Provenance & Evidence