Sodium Hydroxide → Quinoxaline-6-carboxylic acid

Reaction equation

O1C2C=CC([C:10]3[C:19](N4CCC[C@@H]4C)=[N:18][C:17]4[C:12](=[CH:13][CH:14]=[C:15]([C:26]([O:28]C)=[O:27])[CH:16]=4)[N:11]=3)=CC=2OC1.[OH-].[Na+]>CO.O>[N:11]1[C:12]2[C:17](=[CH:16][C:15]([C:26]([OH:28])=[O:27])=[CH:14][CH:13]=2)[N:18]=[CH:19][CH:10]=1

Participants

Procedure

Into a 50-mL round-bottom flask, was placed a solution of methyl 2-(benzo[d][1,3]dioxol-5-yl)-3-((S)-2-methylpyrrolidin-1-yl)quinoxaline-6-carboxylate (94 mg, 0.24 mmol, 1.00 equiv) in methanol (15 mL). This was followed by the addition of a solution of sodium hydroxide (58.9 mg, 1.47 mmol, 5.00 equiv) in water (3 mL) dropwise with stirring. The resulting solution was stirred for 5 hr at 50° C. in an oil bath. The resulting mixture was concentrated under vacuum. The resulting solution was diluted with H2O. The pH value of the aqueous solution was adjusted to 3-4 with 1N aqueous hydrogen chloride. The resulting solids were collected by filtration. The crude product (100 mg) was purified by Prep-HPLC with the following conditions (1#-Waters 2767-2): Column, SunFire Prep C18, 19*150 mm 5 um; mobile phase, water with 0.05% TFA and CH3CN (10% CH3CN up to 80% in 8.5 min, hold 80% in 1 min, up to 100% in 0.1 min, hold 100% in 0.8 min); Detector, UV 220&254 nm. This resulted in 40 mg (44%) of 2-(benzo[d][1,3]dioxol-5-yl)-3-(S)-2-methylpyrrolidin-1-yl)quinoxaline-6-carboxylic acid as a yellow solid.