1-(2-fluorophenyl)-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one synthesis

Yield:630107-82-3 73%

Reaction Conditions:

Stage #1: 5-amino-1-(2-fluorophenyl)-1H-pyrazole-4-carboxamide in formamide at 191; for 3 h;
Stage #2: in water; for 12 h;Cooling;

Steps:

47.3 Step C: (47C)

Step C: (47C) A solution of compound 47B (12 g, 54.5 mmol) in formamide (218 ML) was heated to 191°C (oil-bath temp. ) for 3 h. The solution was cooled to rt and diluted with water (880 mL). The mixture was cooled in the refrigerator overnight. The solid was filtered, washed several times with water and dried in vacuo over phosphorus pentoxide to obtain the tite compound 47C (9.14 g, 73% yield, tan brown powder, HPLC purity: 100%). HPLC retention time: 0.96 min; LC/MS : 231.02 (M+H) +.

References:

WO2003/99820,2003,A1 Location in patent:Page 49; 50