Sulfamic Acid → 6-(2,6-dichlorophenyl)-2-N-[4-(diethylamino)butyl]pyrido[2,3-d]pyrimidine-2,7-diamine

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Reaction Conditions

Reaction Steps

A mixture of 2,7-diamino-6-(2,6-dichlorophenyl)-pyrido[2,3-d]pyrimidine (40 g) from Example 1, sulfamic acid (25.4 g) and diethylaminobutylamine (205 mL) was heated to approximately 150° C. for 28 hours. The reaction temperature was lowered to 50° C., and excess diethylaminobutylamine was removed in vacuo. After cooling to 25° C., the residue was suspended in water. The aqueous solution was made alkaline with a solution of saturated sodium bicarbonate and extracted with dichloromethane several times. The dichloromethane layers were combined, washed several times, first with a saturated solution of sodium bicarbonate then a saturated solution of sodium chloride, dried over magnesium sulfate and concentrated in vacuo. The residue was washed repeatedly with diethyl ether and then crystallized from ethyl acetate. The recrystallized product was further purified by column chromatography, eluting first with ethyl acetate:methyl alcohol:triethylamine (85:14:1) followed by ethyl acetate:ethyl alcohol:triethylamine (9:2:1) to afford 36.2 g of the title compound 6-(2,6-dichlorophenyl)-N2 -(4-diethylamino-butyl)-pyrido[2,3-d]pyrimidine-2,7-diamine, CIMS (1% NH3 in CH4): 461=M+ +C2H5, 433=M+ +H (Base), 417, 403, 360.

Provenance & Evidence