Hydrochloric Acid → 8-methyl-4-oxo-1-(tetrahydro-2H-thiopyran-4-ylmethyl)-4,5-dihydro[1,2,4]triazolo[4,3-a]quinoxaline-7-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To a mixed liquid of 1.70 g of methyl 4-chloro-8-methyl-1-(tetrahydro-2H-thiopyran-4-ylmethyl)[1,2,4]triazolo[4,3-a]quinoxaline-7-carboxylate, 18.0 mL of tetrahydrofuran, and 18.0 mL of methanol was added 9.20 mL of a 3 M aqueous sodium hydroxide solution, followed by stirring at 60° C. overnight. 3 M hydrochloric acid was added thereto to adjust the pH to about 3, and the precipitated solid was collected by filtration and dried under reduced pressure to obtain 1.20 g of 8-methyl-4-oxo-1-(tetrahydro-2H-thiopyran-4-ylmethyl)-4,5-dihydro[1,2,4]triazolo[4,3-a]quinoxaline-7-carboxylic acid as a yellow solid.

Provenance & Evidence