Dichloromethane → tert-butyl 4-(3-methoxy-4-nitrophenyl)-5,6-dihydropyridine-1(2H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

Argon is bubbled for 10 minutes into a mixture of 4.64 g (20.0 mmol) of the product prepared in step 4.1, 6.25 g (20.2 mmol) of 3,6-dihydro-2H-pyridine-1-N-Boc-4-boronic acid pinacol ester (Frontier Scientific) and 8.29 g (60.0 mmol) of potassium carbonate in 125 mL of anhydrous DMF. 0.98 g (1.2 mmol) of PdCl2dppf.CH2Cl2 is added and the mixture is heated under argon at 90°C. for 3 hours. The resulting mixture is diluted with ethyl acetate and washed twice with water and once with saturated aqueous NaCl. The organic phase is dried over Na2SO4, filtered and concentrated under vacuum. The crude solid obtained is purified by chromatography on a column of silica, eluting with a cyclohexane/ethyl acetate gradient (75/25 to 70/30). 6.02 g of a pale yellow solid are obtained, and are triturated in cyclohexane and then drained by suction and dried in an oven. 5.89 g of the expected product are finally recovered in the form of a white solid. Yield=88%.

Provenance & Evidence