Methanol → HCID 86615660, compound

Participants

Reaction Steps

To a solution of (S)-9-[(3,5-bis-trifluoromethyl-benzyl)-(2H-tetrazol-5-yl)-amino]-1,3,6,7,8,9-hexahydro-2-oxa-5-aza-cyclohepta[f]indene-5-carboxylic acid tert-butyl ester (1.17 mmol) in dichloromethane (20 mL), add methanol (5.85 mmol) and triphenylphosphine (3.51 mmol). To this solution, add diethyl azodicarboxylate (3.51 mmol) dropwise at room temperature. After stirring for 12 h, remove the solvent under vacuum and chromatograph the intermediate over silica gel eluting with ethyl acetate/hexane (2-35%) to afford (S)-9-[(3,5-bis-trifluoromethyl-benzyl)-(2-methyl-2H-tetrazol-5-yl)-amino]-1,3,6,7,8,9-hexahydro-2-oxa-5-aza-cyclohepta[f]indene-5-carboxylic acid tert-butyl ester as a colorless oil. To this intermediate in dichloromethane (5 mL), add TFA (2 mL). After stirring for 2 h, quench the reaction with aqueous sodium carbonate (5 mL) and dilute with dichloromethane (10 mL). Separate the organic portion, dry over sodium sulfate, filter, and remove the solvent under vacuum. This provides the title compound as a crude oil that is further used without purification.

Provenance & Evidence