Diisopropylamine → 1-ethyl-6-methoxy-2-tributylstannanyl-1H-indole-3-carbonitrile

Participants

Reaction Conditions

Reaction Steps

A solution of THF (60 mL) and diisopropylamine (5.5 mL, 39 mmol) was cooled to −78° C. n-Butyllithium (14.5 mL, 2.5M in hexanes, 36.2 mmol) was added dropwise over 5 minutes. The LDA mixture was stirred at −78° C. for 10 minutes, and then at 0° C. for 20 minutes. The solution was re-cooled to −78° C. 1-ethyl-6-methoxy-1H-indole-3-carbonitrile (5.0 g, 25 mmol), prepared as in example 1A, was taken up in THF (30 mL) and added dropwise to the LDA mixture over 15 minutes. The reaction was stirred at −78° C. for 10 minutes, and at 0° C. for 30 minutes. Once again, the reaction mixture was cooled to −78° C. Tributyltin iodide (10 mL, 35 mmol) was added dropwise. This was stirred at −78° C. for 15 minutes, and then at 0° C. for 30 minutes. The reaction mixture was absorbed onto silica gel and concentrated. Purification by chromatography (CH2Cl2) yielded 1-ethyl-6-methoxy-2-tributylstannanyl-1H-indole-3-carbonitrile (12.05 g, 98%).

Provenance & Evidence