p-Toluenesulfonic acid → 4-(6-bromo-2-methyl-1H-1,3-benzodiazol-1-yl)pyrimidin-2-amine

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-N-(2-amino-5-bromophenyl)pyrimidine-2,4-diamine (300 mg, 1.07 mmol) in a mixture of methanol (5 mL) and THF (20 mL) was added trimethyl orthoacetate (2.02 ml, 0.02 mol) and TsOH (0.02 ml, 0.11 mmol). The reaction mixture was stirred at 70° C. for 40 min then allowed to stand at RT for 3 days. A saturated aqueous solution of NaHCO3 was added. The product was extracted into DCM (×3) and the organic layers were washed with brine and then dried with Na2SO4, filtered and concentrated in vacuo. The residue was purified by flash chromatography (Isolute column, 1-2% MeOH in DCM) to give the title compound as a yellow solid; 1H NMR (500 MHz, DMSO) δ 2.67 (3H, s), 6.88 (1H, d, J=5.20 Hz), 7.13 (2H, br. s.), 7.41 (1H, dd, J=8.51, 1.89 Hz), 7.58 (1H, d, J=8.51 Hz), 7.86 (1H, d, J=1.89 Hz), 8.48 (1H, d, J=5.20 Hz); LC-MS: m/z=+303.9, 305.7 (M+H)+.

Provenance & Evidence