反应详情

A mixture of 3-amino-6,6-dimethyl-4,6-dihydro-1H-pyrrolo[3,4-c]pyrazole-5-carboxylic acid tert-butyl ester (500 mg; 1.98 mmol; 1 eq.) and 3-chloro-pentane-2,4-dione (226 μL; 1.98 mmol; 1.00 eq.) in AcOH (1.5 mL) was stirred at room temperature for 1 hour whereupon 32% aq. HCl (584 μL; 5.94 mmol; 3 eq.) was added. The resulting mixture was stirred for 4 hours then poured onto iPrOH (6 mL). The formed precipitate was filtered off and dried to afford the title compound (388 mg, 68%) as an off-white solid. 1H NMR (DMSO-d6) δ 10.37 (brs, 2H), 4.59 (s, 2H), 2.83 (s, 3H), 2.62 (s, 3H), 1.74 (s, 6H). HPLC (max plot) 98.1%, Rt 1.97 min. UPLC/MS: (MS+) 234.1 ([M+H]+).

1. additionwas added
2. additionthen poured onto iPrOH (6 mL)
3. filtrationThe formed precipitate was filtered off
4. customdried