Sodium Carbonate → tert-butyl N-[6-[(E)-2-cyclopropylvinyl]pyrimidin-4-yl]carbamate

Participants

Reaction Steps

A mixture of [(E)-2-cyclopropylvinyl]boronic acid (1, 1.0 g, 8.93 mmol), tert-butyl N-tert-butoxycarbonyl-N-(6-chloropyrimidin-4-yl)carbamate (2, 3.24 g, 9.83 mmol), sodium carbonate (2.84 g, 26.8 mmol), 1,4-dioxane (10 mL) and water (3 mL) in a microwave vial was degassed with argon for 10 minutes. To this mixture 1,1-bis(diphenylphosphino)ferrocene-palladium(II)dichloride dichloromethane complex (0.73 g, 0.89 mmol) was added and purged with argon for 5 minutes. After sealing, the vial was irradiated in a microwave reactor at 130° C. for 45 minutes. The reaction mixture was diluted with water (20 mL) and extracted with ethyl acetate (3×30 mL). The organics were washed with water (2×10 mL) and saturated brine solution (1×10 mL). The organics were then separated, dried with sodium sulfate, and filtered before concentration to dryness. The crude residue was purified by column chromatography (silica, ethyl acetate/hexanes=25%) to obtain tert-butyl N-[6-[(E)-2-cyclopropylvinyl]pyrimidin-4-yl]carbamate (3) as a light brown solid. Yield: 370 mg, 16%; MS (ESI) m/z 262.22 [M+1-Boc]+; 1H NMR (400 MHz, DMSO-d6) δ 10.23 (s, 1H), 8.60 (s, 1H), 7.63 (s, 1H), 6.50 (m, 2H), 1.48 (s, 9H), 0.91 (m, 2H), 0.64 (m, 2H)

Provenance & Evidence