Hydrochloric Acid → HCID 67041932, compound

Participants

Reaction Steps

Into a 50-mL round-bottom flask, was placed a solution of methyl 3-(2,3-dihydrobenzo[b][1,4]oxazin-4-yl)-2-phenylquinoxaline-6-carboxylate (166.8 mg, 0.34 mmol, 1.00 equiv, 80%) in methanol (15 mL). This was followed by the addition of a solution of sodium hydroxide (84 mg, 2.10 mmol, 5.00 equiv) in water (1.5 mL) dropwise with stirring. The resulting solution was stirred overnight at 50° C. in an oil bath. The pH value of the aqueous solution was adjusted to 3-4 with 1N aqueous hydrogen chloride and concentrated under vacuum. The crude product (100 mg) was purified by Prep-HPLC with the following conditions (1#-Waters 2767-2): Column, SunFire Prep C18, 5 um, 19*150 mm; mobile phase, water with 0.05% TFA and CH3CN (20% CH3CN up to 35% in 8 min, up to 70% in 8 min, up to 100% in 1.5 min); Detector, uv 220 & 254 nm. This resulted in 40 mg (31%) of 3-(2,3-dihydrobenzo[b][1,4]oxazin-4-yl)-2-phenylquinoxaline-6-carboxylic acid as a orange solid.

Provenance & Evidence