Diisopropylamine → HCID 747438, compound

Participants

Reaction Conditions

Reaction Steps

A solution of diisopropyl amine (13 mL, 100 mmol) and tetramethylethylene diamine (15 mL, 100 mmol) in THF (150 mL) was cooled in dry ice-acetone bath under argon atmosphere. A 2.5N solution of n-butyl lithium in hexane (40 mL, 100 mmol) was added over 30 minutes and EtOAc (10 mL, 108 mmol) was added and solution stirred for additional 30 minutes. A solution of N-BOC methyl indole-3-carboxylate (IIIa) (6.875 g, 25 mmol), in THF (50 mL) was added rapidly and the reaction mixture was stirred at −78° C. for 1 h and then at −15° C. for an additional 1 h. Reaction mixture was allowed to warm to 15° C., and the reaction was quenched with glacial acetic acid (10 mL). Ethyl acetate (250 mL) was added and the organic layer was successively washed with 1N citric acid solution (2×150 mL), saturated brine (2×100 mL), the organic layer was dried over anhydrous sodium sulphate, filtered and concentrated in vacuo. The crude product was purified was purified by flash chromatography over silica gel and 1:1 ethyl acetate and hexane were used as eluent to provide the desired compound (Va) (1.2 g) and its N-BOC derivative (Vb) (1.2 g) in a combined yield of 30%.

Provenance & Evidence