Sodium Bicarbonate → 1,1-Dimethylethyl (2,3-dihydro[1,4]dioxino[2,3-c]pyridin-7-ylmethyl)(1-{2-[6-(methyloxy)-3-oxopyrido[2,3-b]pyrazin-4(3H)-yl]ethyl}-4-piperidinyl)carbamate

Participants

Reaction Steps

A mixture of [7-(methyloxy)-2-oxopyrido[2,3-b]pyrazin-1(2H)-yl]acetaldehyde (as the methyl hemiacetal) (969 mg, 3.510 mmol) and 1,1-dimethylethyl (2,3-dihydro[1,4]dioxino[2,3-c]pyridin-7-ylmethyl)-4-piperidinylcarbamate (for a synthesis see WO2004/058144 Example 99(h)) (1.22 g, 3.510 mmol) in chloroform (40 ml) was stirred for 1 h before addition of NaBH(OAc)3 (377 mg, 1.59 mmol). The reaction was stirred for 1 h more before addition of sat. aq NaHCO3 (100 ml). The reaction was then extracted with 10% MeOH in DCM (3×200 ml). The combined organic phases were dried, evaporated and the crude residue purified by chromatography on silica gel using a 0-10% MeOH/DCM gradient to provide the desired compound as an impure yellow foam (1.408 g, 73%).

Provenance & Evidence