Methanol → tert-butyl 4-[2-(5-hydroxy-7-oxo-5H-[1,3]dioxolo[4,5-f]isoindol-6-yl)ethyl]piperidine-1-carboxylate

Participants

Reaction Steps

To a reaction vessel, 92 g (0.23 mol) compound XI, 250 ml methanol and 250 ml tetrahydrofuran were added while stirring, the mixture was cooled to 0˜10° C., 10 g (0.26 mol) sodium borohydride was added, the reaction was kept at 0˜10° C. for 20-30 min, 100 ml water was added, the reaction mixture was concentrated to dry under reduced pressure (at 45° C.), The residue was added 500 ml ethyl acetate and 300 ml water, and extracted, the organic layer was collected, dried over sodium sulfate, concentrated to a minor amount, 300 ml petroleum ether was added, a solid was precipitated out, filtered, the filter cake was washed wth petroleum ether, dried, and 64.7 g compound VII-1 was obtained, with yield of 70%. 1H NMR (DMSO-d6): δ 0.95-1.04 (m, 2H), 1.39 (s, 10H), 1.51 (m, 2H), 1.70 (dd, 2H, J=25.0, 12.4 Hz), 2.65 (br s, 2H), 3.23-3.30 (m, 1H), 3.54-3.61 (m, 1H), 3.90 (d, 2H, J=10.0 Hz), 5.67 (d, 1H, J=8.9 Hz), 6.12 (s, 1H), 6.13 (s, 1H), 6.50 (d, 1H, J=9.0 Hz), 7.08 (s, 1H), 7.09 (s, 1H); MS (ESI): m/z 427 [M+Na]+.

Provenance & Evidence