3,4-Dichlorobenzyl chloride → Ethyl 3-formyl-N-(3,4-dichlorobenzyl)indole-2-carboxylate

Participants

Reaction Steps

Sodium hydride (488 mg, 60% in mineral oil) was added to a stirred solution of ethyl 3-formylindole-2-carboxylate (2.21 g) in DMF (100 ml) under argon, and reaction stirred at ambient temperature for 25 minutes. 3,4-Dichlorobenzyl chloride (1.71 ml) was then added and the reaction stirred overnight. The reaction mixture was concentrated in vacuo and the residue dissolved in ethyl acetate (80 ml) and washed with water (2×80 ml), dried (MgSO4) and concentrated in vacuo to give a crude residue which was purified by column chromatography using ethyl acetate:iso-hexane as eluent (gradient 5/95-100/0), to give the product as a yellow solid (2.17 g, 57%); NMR d (CD3SOCD3) 1.25 (t, 3H), 4.40 (q, 2H), 5.80 (s, 2H), 7.00 (m, 1H), 7.30-7.50 (m, 3H), 7.55 (m, 1H), 7.65 (m, 1H), 8.35 (m, 1H), 10.48 (s, 1H); M/z (+) 376.4 (MH+).

Provenance & Evidence