Water → 2-(1-tert-butoxycarbonyl-1H-thieno[3,2-c]pyrazol-3-yl)-5-formyl-indole-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a solution of 2-(1-tert-butoxycarbonyl-1H-thieno[3,2-c]pyrazol-3-yl)-5-hydroxymethyl-indole-1-carboxylic acid tert-butyl ester [373 mg, 0.794 mmol Intermediate (10)] in Dichloromethane (20 mL) is added Dess-Martin Periodinane (407 mg, 0.959 mmol). Stirred at room temperature for 30 minutes. Water (10 mL) is added and stirred for 30 minutes at room temperature. The reaction mixture is dissolved with ethyl acetate (30 mL) and washed twice with a mixture of 10% Na2S2O3/saturated NaHCO3 (4 mL) solution. The ethyl acetate phase is washed with water, NaHCO3, brine and dried over sodium sulfate. The residue is chromatographed on 10 g silica gel cartridge eluting with 30 to 40% ethyl acetate gradient in heptane to afford 2-(1-tert-butoxycarbonyl-1H-thieno[3,2-c]pyrazol-3-yl)-5-formyl-indole-1-carboxylic acid tert-butyl ester [300 mg, 81%, Intermediate (11)] as a white solid; 1H NMR [(CD3)2SO)]: δ 10.079 (1H, s, CHO), 8.323 (1H, s), 8.318 (1H, d), 8.017 (1H, s), 7.978 (1H, d), 7.391 (1H, d), 7.345 (1H, s), 1.660 (9H, s), 1.341 (9H, s); TLC data Rf=0.37 (30% ethyl acetate in heptane).

Provenance & Evidence