1791-73-7

1118-61-2

50-01-1

1791-73-7

The general procedure for the synthesis of 6-methyl-2,4-pyrimidinediamines from 3-aminobut-2-enenenitrile and guanidine hydrochloride was carried out as follows: according to the method described in Aust. J. Chem. 1984, vol. 37, pp. 1195-1201. First, guanidine hydrochloride (23.8 g) was added to a methanol solution (51 mL) of methanol (50 mL) and 28% sodium methanol and stirred for 30 min at room temperature. Subsequently, the precipitated salt was removed by filtration and the solution was concentrated under reduced pressure to give a solution of the product without guanidine. Next, 3-aminobut-2-enenenitrile (16.4 g) and 1-butanol (60 mL) were added to this solution. The reaction mixture was heated and stirred at 110 °C for 10 h under nitrogen protection. Upon completion of the reaction, the precipitated salt was removed by thermal filtration, and acetone (100 mL) was added to the filtrate and stirred under ice bath cooling for 30 min to obtain the crude product. The crude product was recrystallized by acetone to give 2,4-diamino-6-methylpyrimidine (10.5 g). Next, methyl benzoate (23 g, 169 mmol) and sodium methanol (22 g, 407 mmol) were added to a solution of N-ethylpyrrolidone (100 mL) in 2,4-diamino-6-methylpyrimidine (10 g, 81 mmol) and stirred under heat at 40 °C for 2 hours. Upon completion of the reaction, the reaction system was cooled to room temperature, poured into a 1N aqueous hydrochloric acid solution and filtered to collect the solid. The crude product was recrystallized by 2-propanol to give the target compounds (1-2). Finally, compounds (1-2) were subjected to NMR spectroscopic analysis with the following results: 1H-NMR (solvent: d6-DMSO, internal standard: tetramethylsilane) δ (ppm) 2.50 (3H, s), 7.45-7.70 (6H, m), 7.90 (1H, s), 7.95-8.05 (4H, m), 10.88 (1H, s), 11.10 (1H, s).