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

Provenance & Evidence