Sodium Carbonate → 6-Benzyl-2-(2,6-dimethylphenyl)-4-methoxy-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine

Participants

Reaction Conditions

Reaction Steps

To a suspension of 6-benzyl-2-chloro-4-methoxy-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine (6.52 g, 22.5 mmol) and 2,6-dimethylphenylboronic acid (3.90 g, 26.0 mmol) in 1,2-dimethoxyethane (175 mL), was added 2 M aqueous Na2CO3 (35.2 mL, 70.5 mmol) and tetrakis(triphenylphosphine)palladium(0) (0.751 g, 0.651 mmol). The reaction was flushed with nitrogen, then heated to 100° C. for 48 h. The reaction mixture was cooled to r.t., then ethyl acetate and brine were added. The aqueous layer was extracted by ethyl acetate twice. The combined ethyl acetate layers were dried over Na2SO4, filtered, and concentrated. The resulting residue was purified via silica gel FCC (0-40% EtOAc/heptane) to give 6-benzyl-2-(2,6-dimethylphenyl)-4-methoxy-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine. 1H NMR (400 MHz, CD2Cl2) δ ppm 7.23-7.46 (m, 5 H), 7.12-7.21 (m, 1 H), 7.04-7.10 (m, 1 H), 6.97 (d, J=7.6 Hz, 1 H), 3.94 (d, J=10.1 Hz, 3 H), 3.73 (d, J=16.4 Hz, 2 H), 3.36-3.56 (m, 2 H), 2.91 (d, J=4.8 Hz, 1 H), 2.84 (br. s., 2 H), 2.77 (t, J=5.4 Hz, 1 H), 2.35 (s, 3 H), 2.08 (s, 3 H). MS (ESI+) m/z 360.3 (M+H)+.

Provenance & Evidence