Hydrochloric Acid → (E)-3-(8-({[4-(tert-Butyl)-1,3-thiazol-2-yl]amino}carbonyl)-2-{3-[(dimethylamino)-carbonyl]piperidino}-4-oxo-4H-pyrido[1,2-a]pyrimidin-3-yl)-2-propenoic acid

Participants

Reaction Steps

The methyl (E)-3-(8-({[4-(tert-butyl)-1,3-thiazol-2-yl]amino}carbonyl)-2-{3-[(dimethylamino)carbonyl]piperidino}-4-oxo-4H-pyrido[1,2-a]pyrimidin-3-yl)-2-propenoate (63.7 mg, 0.11 mmol) obtained in (C) was dissolved in methanol (10 ml), added dropwise with 1 N aqueous sodium hydroxide (562.0 μl, 0.56 mmol), and stirred at room temperature for 1 hour. The reaction solution was further added with 1 N aqueous sodium hydroxide (5.62 ml, 5.62 mmol), stirred at room temperature for 2 hours, further added with 1 N aqueous sodium hydroxide (2.81 ml, 2.81 mmol), and stirred at room temperature for 3 hours. The reaction solution was adjusted to about pH 2 with 1 N hydrochloric acid aqueous solution and extracted with chloroform/methanol (10:1, v/v). The organic layer was washed with saturated brine and dried over anhydrous sodium sulfate, and the solvent was evaporated. The residue was purified by preparative TLC (chloroform:methanol=20:1, v/v) and lyophilized from dioxane to obtain the title compound (37.6 mg, 38.5%, for the three steps) as yellow orange powder.

Provenance & Evidence