4-Methoxybenzylamine → N4-(3,4-dichlorophenyl)-N6-(4-methoxybenzyl)pyrido[3,4-d]pyrimidine-4,6-diamine

Participants

Reaction Conditions

Reaction Steps

A mixture of compound 204 (2.95 g, 9.55 mmol) and 4-methoxybenzylamine (12.6 mL, 95.5 mmol) in dry DMSO (20 mL) was stirred under a nitrogen atmosphere at 52° C. (bath temperature) for 10 days. The solution was then cooled and petroleum ether (200 mL) was added. It was stirred at room temperature for 10 min. The layers were allowed to separate and the petroleum ether layer was decanted. This procedure was repeated with more petroleum ether (2×200 ml). Water (200 mL) was added and the mixture was stirred at room temperature for 15 min. It was filtered and washed solid with water (5×30 mL), then with petroleum ether (3×30 mL). The sticky yellow/orange solid was stirred with acetone (100 mL) at 35-45° C. (internal temperature) for 10 min. Water (100 mL) was added and stirred at room temperature for 20 min. The solid was collected by suction-filtration, washed with water/acetone (1:1) (5×20 mL), and dried in vacuum over silica-gel/KOH to give pure N4-(3,4-dichlorophenyl)-N6-(4-methoxybenzyl)pyrido[3,4-d]pyrimidine-4,6-diamine (213) (2.59 g, 64%) as a yellow/orange solid, mp 209-211° C.; 1H NMR δ [(CD3)2SO] 9.76 (s, 1H), 8.77 (s, 1H), 8.42 (s, 1H), 8.30 (poorly resolved d, J=2.1 Hz, 1H), 7.89 (dd, J=8.8, 2.1 Hz, 1H), 7.64 (d, J=8.8 Hz, 1H), 7.38-7.25 (m, 3H), 7.17 (s, 1H), 6.92-6.83 (m, 2H), 4.49 (d, J=6.3 Hz, 2H), 3.71 (s, 3H). Anal. Calcd for C21H17Cl2N5O: C, 59.17; H, 4.02; N, 16.43%. Found C, 58.93; H, 4.17; N, 16.12%.

Provenance & Evidence