Sodium Bicarbonate → Methyl 3-(2-oxa-6-azaspiro[3.3]heptan-6-ylsulfonyl)-5-(trifluoromethyl)benzoate

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Reaction Steps

To an ice-cooled solution of methyl 3-(chlorosulfonyl)-5-(trifluoromethyl)benzoate (1 g, 1.33 mmol, Buttpark Ltd.) in CH2Cl2 (10 mL) was added N,N-ethyldiisopropylamine (1.28 g, 1.73 mL, 9.91 mmol, Eq: 3) and 2-oxa-6-aza-spiro[3.3]heptane oxalate (524 mg, 1.82 mmol). The reaction mixture was stirred for 2 hours at room temperature. The reaction mixture was poured on 30 mL 10% aqueous NaHCO3 solution and 30 mL CH2Cl2 and the layers were separated. The aqueous layer was extracted a second time with 30 mL CH2Cl2. The organic layers were washed with 30 mL brine, dried over MgSO4, filtered and concentrated under vacuum. The compound was purified by silica gel chromatography on a 20 g column using an MPLC (Flashmaster) system eluting with a gradient of n-heptane:EtOAc (100:0 to 30:70). Colorless solid (460 mg, 38.1%). MS (ESI): m/z=365 [M+H]+.

Provenance & Evidence