1H-1,2,4-Triazole → 6-Chloro-4-(1H-1,2,4-triazol-1-yl)pyrido[3,2-d]pyrimidin-2-amine

Participants

Reaction Steps

A solution of 1,2,4-triazole (1.4 g, 20 mmol) and phosphorus oxychloride (1.4 mL, 15 mmol) in dry acetonitrile (40 mL) was adder to a stirred suspension of 2-amino-6-chloro-3H-pyrido[3,2-d]pyrimidin-4-one (1 g, 5 mmol) and N-N-di-isopropyl-ethyl-amine (DIEA; 4.4 ml, 25 mmol) in dry acetonitrile (30 ml). The mixture was stirred at room temperature for 24 hours. 2 molar equivalents of 1,2,4-triazole (0.7 g, 10 mmol), 1.5 equivalent of phosphorus oxychloride (0.7 ml, 7.5 mmol) and 2.5 equivalents of DIEA (2.2 ml, 12.5 mmol) were added to the mixture. After stirring at room temperature for 48 hours, the same amount of the above reagents was added again. The reaction mixture was stirred for 7 full days and the yellow precipitate was filtered off, washed successively with acetonitrile, DCM and ether. The solid was dried under vacuum, providing the pure title compound as a yellow solid (667 mg, yield 53%) which was characterised as follows: MS (m/z) 248.8 [M+H]+.

Provenance & Evidence