Hydrochloric Acid → 2-(3-Hydroxyphenoxymethyl)-6-methylbenzoic Acid

Participants

Reaction Conditions

Reaction Steps

7-Methylphthalide (30.1 g, 203 mmol), resorcinol (45.3 g, 407 mmol) and potassium tert-butoxide (47.6 g, 424 mmol) are suspended in 300 ml of N-methylpyrrolidone (NMP) and stirred at 140° C. for 21 h. After this time, a second amount of potassium tert-butoxide (2.4 g, 21.4 mmol) is added and stirring is continued at 140° C. for 2.5 h. The reaction mixture is cooled, 800 ml of water are added, and the mixture is acidified to pH=2 at 20° C. with concentrated hydrochloric acid. After stirring at 3 to 5° C. for 2 hours, the pale beige solid is filtered off with suction, washed with water and then dried. The isolated product contains 2-(3-hydroxyphenoxymethyl)-6-methylbenzoic acid and N-methylpyrrolidone as solvate molecule in a ratio of 1:1. Yield 77.7%, melting point 98 to 99° C.

Provenance & Evidence