6-Des(diethanolamino)-6-chloro Dipyridamole synthesis

Yield:-

Reaction Conditions:

in dimethyl sulfoxide at 25 - 125;

Steps:

2.1

Diethanolamine (3 eq) and 2,6-dichloro-4,8-dipiperidino-pyrimido(5,4-d)pyrimidine (1 eq) were added to dimefhylsulfoxide (10 vol) at 25-30°C, stirred for 10 minutes and then heated at 120-125°C for 4-5 hours. After completion of the reaction, the reaction mixture was cooled to 55-60°C. Acetone (5 vol) was added at 55-60°C and the mixture was stirred at 55-60°C for 10 minutes. Purified water (15 vol) was added at 55-60°C and the mixture was stirred at 50-55°C for 15 minutes. The mixture was cooled to 25-30°C and stirred at 25-30°C for 30 minutes. The precipitated solid was filtered, washed with purified water (2 x 5 vol) and dried at 75-80°C under reduced pressure to afford crude 2-chloro-6- diethanolamino-4,8-dipiperidino-pyrimido(5,4-d)pyrimidine as a yellow crystalline solid. Yield (w/w) = 110-120%Yield (molar) = 93-100%HPLC purity > 96%

References:

WO2011/151640,2011,A1 Location in patent:Page/Page column 19