Sodium Dithionite → HCID 59846511, compound

Participants

Reaction Steps

A freshly prepared solution of sodium hydrosulfite (tech, 100 mg) and sodium bicarbonate (50 mg) in H2O (5 mL) was added to a solution of N4-(2,6-difluorobenzyl)-N2-(5-fluoro-2-nitrophenyl)-5-nitropyrimidine-2,4-diamine (75) (24 mg) in THF (5 mL). The mixture was stirred vigorously for 30 min and extracted with DCM (3×). The combined organics were washed with brine, dried, filtered and concentrated to yield the intermediate N4-(2,6-difluorobenzyl)-N2-(2-amino-5-fluorophenyl)pyrimidine-2,4,5-triamine (76) for use in the next step. A catalytic amount of para-toluene sulfonic acid monohydrate was added to a solution of the intermediate and trimethyl orthoformate (1 mL) in MeOH (2 mL), after 2 hr conc. HCl (1 mL) was added and the mixture was heated at 50° C. for 4 hr. The reaction solvents were removed and the crude material was purified via preparative HPLC to give 9-(2,6-Difluorobenzyl)-2-(6-fluoro-1H-benzo[d]imidazol-1-yl)-9H-purine (78) as the TFA salt in low yield (0.8 mg) MH+=404, 1H NMR (5% CD3OD/CDCl3) δ 9.1 (s, 1H), 9.0 (s, 1H), 8.3 (d, 1H), 8.2 (s, 1H), 7.6 (m, 1H), 7.0 (t, 1H), 6.9 (m, 2H), 5.5 (s, 2H) ppm, 19F NMR δ−76.6 (s, TFA), −114.5 (m), −117.1 (m).

Provenance & Evidence