Citric Acid → HCID 58306597, compound

Participants

Reaction Steps

To 1-methyl-5,6,7,8-tetrahydro-2H-[1]benzothieno[2,3-d][1,3]oxazine-2,4(1H)-dione (0.50 g) was added ethanol (20 mL), and triethylamine (0.44 mL) and methyl 4-[(1S)-1-aminoethyl]benzoate hydrochloride were sequentially added, followed by heating with reflux for 18 hours. The reaction mixture was cooled to room temperature, and a 10% aqueous citric acid solution (15 mL) was added thereto. To a mixture was added ethyl acetate, followed by washing with water, and the obtained organic layer was dried over anhydrous sodium sulfate. After filtering and concentrating under reduced pressure, the residue was purified by silica gel column chromatography (hexane/ethyl acetate: 90/10-75/25) to obtain methyl 4-[(1S)-1-({[2-(methylamino)-4,5,6,7-tetrahydro-1-benzothiophen-3-yl]carbonyl}amino)ethyl]benzoate (0.42 g).

Provenance & Evidence