Sodium Carbonate → tert-butyl (3-(6-ethyl-2-(methylsulfinyl)-7-oxopyrido[2,3-d]pyrimidin-8(7H)-yl)phenyl)carbamate

Participants

Reaction Conditions

Reaction Steps

At 0° C., a suspension of tert-butyl (3-(6-ethyl-2-(methylthio)-7-oxopyrido[2,3-d]pyrimidin-8(7H)-yl)phenyl)carbamate (55) (720 mg, 1.75 mmol) in DCM (15 mL) was treated with 3-chloroperoxybenzoic acid (70 wt. %, 460 mg, 1.87 mmol) in one portion and stirred at 0° C. for 1 h. The reaction mixture was diluted with DCM (15 mL), and treated with ice and a 10% solution of Na2CO3 (ca. 10 mL). The DCM layer was separated and the aqueous layer was extracted with an additional amount of DCM (2×50 mL), dried over sodium sulfate and concentrated to give tert-butyl (3-(6-ethyl-2-(methylsulfinyl)-7-oxopyrido[2,3-d]pyrimidin-8(7H)-yl)phenyl)carbamate (6a) (682 mg, 1.59 mmol, 91% yield) as a light yellow amorphous solid. m/z (ESI, +ve ion) 451.0 (M+Na)+. The crude material was used in the subsequent step without further purification.

Provenance & Evidence