Trichloroacetyl isocyanate → Ethyl 8-[(aminocarbonyl)amino]-1-methyl-1H-pyrazolo[4,3-h]quinazoline-3-carboxylate

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Reaction Steps

1.00 g (3.7 mmol) of ethyl 8-amino-1-methyl-1H-pyrazolo[4,3-h]quinazoline-3-carboxylate were dissolved in 50 mL of pyridine and 1 mL (8.0 mmol) of trichloroacetylisocyanate were added. The mixture was stirred overnight at room temperature. The solvent was then evaporated under reduced pressure and the residue was treated with 50 mL of methanol. After 2 hours under stirring the solvent was removed, the residue redissolved with dichloromethane and washed with a diluted solution of ammonium hydrate. After drying over anhydrous Na2SO4 the organic layer was evaporated to dryness and the residue purified by chromatography on a silica gel column (eluant: dichloromethane/acetone 4/1) leading 0.40 g (34% yield) of the title compound.

Provenance & Evidence