Trifluoroacetic acid → HCID 9817403, compound

Participants

Reaction Steps

To a solution of [5-amino-3-(4-methoxy-phenyl)-4-oxo-3,4-dihydro-thieno[3,4-d]pyridazin-1-yl]carbamic acid tert-butyl ester (140 mg, 0.36 mmol, prepared as described in example 33) in dichloromethane (20 ml) was added trifluoroacetic acid (5 ml) and the reaction mixture was stirred at room temperature for 1 h. The volatiles were evaporated in vacuo and the residue was dissolved in ethanol and evaporated in vacuo. The semi solid residue was treated with diethyl ether (25 ml) for 16 h, the precipitate was filtered off and dried in vacuo at 50° C. for 16 h affording 30 mg crude title compound. The diethyl ether phase was evaporated and the residue was purified on silica gel (200 ml) using a mixture of ethyl acetate and heptane (3:1) as eluent. Pure fractions were collected and the solvent evaporated in vacuo affording 20 mg (19%) of the title compound as a solid.

Provenance & Evidence