Sodium Carbonate → 4-Benzo[1,3]dioxol-4-yl-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

Tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5,6-dihydropyridine-1(2H)-carboxylate (1.62 g, 5.22 mmol) was added to a solution of 4-bromobenzo[d][1,3]dioxole (1 g, 4.97 mmol) in 1,2-Dimethoxyethane (45.0 ml) and Na2CO3 2M (8.28 ml, 16.6 mmol). The resulting suspension was degassed using a stream of argon in an ultrasonic bath during 5 min. Then triphenylphosphine (261 mg, 995 μmol) and palladium (II) acetate (112 mg, 497 μmol) was added and the reaction mixture was stirred over night at 85° C. The reaction was cooled to rt, diluted with 40 mL of water and the mixture extracted with ethyl acetate (3×50 mL). The organic layers were dried over MgSO4 and concentrated under vacuum. The crude material was purified by flash chromatography (silica gel, 50 g, 0% to 50% EtOAc in heptane) to yield 4-Benzo[1,3]dioxol-4-yl-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester as a yellowish liquid (1.22 g, 80.8%). MS (ISP) m/z=304.4 [(M+H)+].

Provenance & Evidence