2-AMINO-5-CHLORO-3H-PYRIMIDO[4,5-B]INDOL-4(9H)-ONE synthesis

Yield:1126602-45-6 78%

Reaction Conditions:

Stage #1: ethyl 2-amino-4-chloro-1H-indole-3-carboxylate;chloroformamidine hydrochloride in dimethylsulfone at 110 - 120; for 0.5 h;
Stage #2: with ammonia in dimethylsulfone;water;

Steps:

3

2-Amino-5-chloro-3,9-dihydro-4H-pyrimido[4,5-b]indol-4-one (8) 1 g methyl sulfone was heated to melting. 7 (106.22 mg, 1.37 mmol) was added and the resulting mixture was stirred and heated at 110-120° C. to dissolve completely. 5 (200 mg, 0.837 mmol) was added in one part to the reaction mixture. Stirring was continued for 30 minutes. About 10 mL water was added to quench the reaction. Ammonia water was added to neutralize the reaction mixture. Solid precipitated out. This solid was filtered. Obtained solid was dissolved in chloroform and methanol, dried (using Na₂SO₄) and recrystallized.

References:

US2009/62318,2009,A1 Location in patent:Page/Page column 15; 16-17