Sodium hydride → [2-(1,3-Dimethyl-2,4-dioxo-1,2,3,4-tetrahydro-pyrrolo[3,4-d]pyrimidin-6-yl)-ethyl]-carbamic acid tert-butyl ester

Participants

Reaction Steps

1,3-Dimethyl-1H-pyrrolo[3,4-d]pyrimidine-2,4(3H,6H)-dione) (step 1) (4.43 g, 24.72 mmol) and sodium hydride (commercial) (60% dispersion in mineral oil) (1.286 g, 32.1 mmol) were degassed with nitrogen for 15 min. The reagents were then suspended in anhydrous THF (44.5 mL) and stirred for 15 mins at room temperature, then cooled to 0° C. (external). After 10 mins, a solution of tert-butyl-1,2,3-oxathiazolidine-3-carboxylate 2,2-dioxide (step 2) (6.07 g, 27.2 mmol) in anhydrous THF (44.5 mL) was charged in two portions (2×24 mL). After addition was complete, the ice-bath was removed and the reaction stirred at room temperature for 50 mins. The reaction was then quenched by addition of saturated NH4Cl solution (30 mL). The reaction mixture was diluted with water (30 mL), EtOAc (60 mL) and the layers separated. The aqueous layer was extracted with EtOAc (2×50 mL), saturated with NaCl (s) and extracted with MeCN (4×50 mL). The aqueous layer was evaporated to (˜20 mL) and extracted further with MeCN (3×50 mL). The combined organic layers were dried (Na2SO4) and filtered under reduced pressure and the solvent was evaporated. The resulting solid was adsorbed onto silica and purified via ISCO SiO2 125 g column eluting with 60-95% EtOAc/hexane. The fractions containing product were combined and evaporated to afford a white crystalline solid. The solid was dried under vacuum at 50° C. for 3 h. The title compound was afforded as a white crystalline solid.

Provenance & Evidence