Ethyl Acetate → tert-butyl (3-(2-(methylthio)-7-oxopyrido[2,3-d]pyrimidin-8(7H)-yl)phenyl)carbamate

Participants

Reaction Conditions

Reaction Steps

LiHMDS (41.6 mL of 1.0 M in THF solution, 41.6 mmol) was added to 2-MeTHF (70 mL) at −78° C. and treated with EtOAc (4.34 mL, 44.4 mmol). The solution was stirred at −78° C. for 10 min, then solid tert-butyl (3-((5-formyl-2-(methylthio)pyrimidin-4-yl)amino)phenyl)carbamate (50) (5.00 g, 13.87 mmol) was added in one portion and the solution was stirred at −78° C. for 10 min then removed from the cooling bath warmed to RT for 3 h. The reaction was cooled in an ice bath and quenched with a saturated solution of NH4Cl and extracted with EtOAc (2×100 mL), dried over MgSO4, filtered and concentrated. The crude solid was suspended in Et2O (50 mL) and collected by filtration, washed with Et2O (2×15 mL) and dried under vacuum affording tert-butyl (3-(2-(methylthio)-7-oxopyrido[2,3-d]pyrimidin-8(7H)-yl)phenyl)carbamate (51) (4.24 g, 11.03 mmol, 80% yield) as a pale yellow solid. 1H NMR (400 MHz, CDCl3) δ ppm 8.60-8.65 (1H, m), 7.64-7.71 (1H, m), 7.52 (1H, s), 7.39-7.47 (1H, m), 7.29 (2H, dd, J=8.3, 1.3 Hz), 6.89-6.95 (1H, m), 6.71 (1H, d, J=9.6 Hz), 6.56 (1H, s), 2.19 (3H, s), 1.50 (9H, s). m/z (ESI, +ve ion) 385.0 (M+1)+.

Provenance & Evidence