Trifluoroacetic acid → Methyl 7-methoxy-2-oxo-1-(2-oxoethyl)-1,2-dihydroquinoline-3-carboxylate

Participants

Reaction Steps

To 0.37 g of methyl 1-(1,3-dioxolan-2-ylmethyl)-7-methoxy-2-oxo-1,2-dihydroquinoline-3-carboxylate, 2 mL of 90% aqueous trifluoroacetic acid solution was added and stirred for 4 hours. The solvent was removed under reduced pressure, and aqueous saturated sodium hydrogen carbonate solution and chloroform were added. The organic layer was separated, and the aqueous layer was extracted with chloroform. The organic layer and extracts were combined, washed with aqueous saturated sodium chloride solution, dried over anhydrous magnesium sulfate, and the solvent was removed under reduced pressure to give 0.44 g of methyl 7-methoxy-2-oxo-1-(2-oxoethyl)-1,2-dihydroquinoline-3-carboxylate. (2) To 5 mL of a dichloromethane solution containing 0.44 g of methyl 7-methoxy-2-oxo-1-(2-oxoethyl)-1,2-dihydroquinoline-3-carboxylate, 0.46 g of tert-butyl (2,3-dihydro-1,4-benzodioxin-6-ylmethyl)(piperidin-4-yl)carbamate and 60 μL of acetic acid were added and stirred for 1 hour. To the reaction mixture, 0.37 g of sodium triacetoxyborohydride was added and stirred for 2 hours. Chloroform and water were added, the organic layer was separated, and the aqueous layer was extracted with chloroform. The organic layer and extracts were combined, washed with aqueous saturated sodium chloride solution, dried over anhydrous magnesium sulfate, and the solvent was removed under reduced pressure to give 0.31 g of methyl 1-(2-(4-((tert-butoxycarbonyl) (2,3-dihydro-1,4-benzodioxin-6-ylmethyl)amino)piperidin-1-yl)ethyl)-7-methoxy-2-oxo-1,2-dihydroquinoline-3-carboxylate as a yellow oil.

Provenance & Evidence