Pentane → 5-Chloro-3-(2-methoxypyridin-3-yl)-3-hydroxy-1,3-dihydroindol-2-one

Participants

Reaction Conditions

Reaction Steps

A 1.7 M solution of tert-butyllithium in pentane (28.9 ml, 49.1 mmol) was added to THF (100 ml) at −78° C. 2-Bromomesitylene (3.6 ml, 23.4 mmol) was added dropwise and the mixture stirred at −78° C. for 1 h. 2-Methoxypyridine (1.92 ml, 18 mmol) was added at −78° C. and then the mixture was stirred at 0° C. for 1 h and at ambient temperature for 0.5 h. A suspension of 5-chloroisatin (1.27 g, 9.0 mmol) in THF (50 ml) was added dropwise at −78° C. The reaction mixture was allowed to warm to room temperature and then saturated ammonium chloride solution was added. The mixture was extracted three times with ethyl acetate, and the collected extracts were washed with saturated brine. The organic phase was dried over magnesium sulfate, filtered and concentrated under reduced pressure. Purification by crystallization from dichloromethane yielded 1.1 g of the intermediate.

Provenance & Evidence