Triethylamine → 2,2-Dimethyl-propionic acid 3-methoxy-9-oxo-8-(2,4,6-trimethyl-phenyl)-2,3,4,5-tetrahydro-1H,9H-pyrazolo[1,2-a][1,2,5]triazepin-7-yl ester

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Reaction Conditions

Reaction Steps

To a solution of 3-methoxy-8-(2,4,6-trimethyl-phenyl)-tetrahydro-pyrazolo[1,2-a][1,2,5]triazepine-7,9-dione (162 mg, 0.51 mmol), triethylamine (0.107 ml, 78 mg, 0.77 mmol) and a catalytic amount of 4-dimethylaminopyridine in tetrahydrofuran (4 ml) at 0° C. was added 2,2-dimethyl-propionyl chloride (pivaloyl chloride, 0.082 ml, 80 mg, 0.67 mmol) dropwise. The suspension was stirred at 0° C. for 45 minutes, the solvent evaporated and the residue diluted with ethyl acetate. The organic phase was washed with water and brine, dried over sodium sulfate and concentrated. Yield: 160 mg of 2,2-dimethyl-propionic acid 3-methoxy-9-oxo-8-(2,4,6-trimethyl-phenyl)-2,3,4,5-tetrahydro-1H,9H-pyrazolo[1,2-a][1,2,5]triazepin-7-yl ester (title compound P1.1) as an off-white solid, mp 147-148° C.

Provenance & Evidence