7-Oxa-3-azabicyclo[4.1.0]heptane-3-carboxylic acid, 1,1-dimethylethyl ester

85838-94-4

161157-50-2

The general procedure for the synthesis of tert-butyl 7-oxa-3-azabicyclo[4.1.0]heptane-3-carboxylate from N-Boc-1,2,3,6-tetrahydropyridine was carried out as follows: tert-butyl 5,6-dihydropyridine-1(2H)-carboxylate (2.00 g, 10.9 mmol) was dissolved in dichloromethane (DCM) as described in the literature WO 97/10212 and added with m-chloroperoxybenzoic acid (MCPBA, 4.16 g, 18.6 mmol). The reaction mixture was stirred at room temperature for 16 hours. After completion of the reaction, the reaction mixture was washed sequentially with saturated aqueous sodium metabisulfite solution, saturated aqueous sodium bicarbonate solution, 1N aqueous sodium hydroxide solution and saturated brine. The organic layer was separated, dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give tert-butyl 7-oxa-3-azabicyclo[4.1.0]heptane-3-carboxylate (2.04 g, 94% yield) as an oil. The product was characterized by 1H NMR (400 MHz, CDCl3) with chemical shift δ of 1.45 (s, 9H), 1.91 (m, 1H), 2.04 (br, 1H), 3.11 (m, 1H), 3.21 (br, 1H), 3.29 (m, 1H), 3.45 (br, 1H), 3.70 (br, 1H), 3.88 (br 1H).