Ammonia → HCID 18670356, compound

Participants

Reaction Steps

1.04 g of (10-methoxymethyl-10H-pyrazino[2,3-b][1,4]benzothiazin-8-yl)carboxylic acid was dissolved in a mixture of dichloromethane (20 ml) with tetrahydrofuran (20 ml) in a nitrogen atmosphere. Under ice-cooling, 1.04 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 200 mg of 1-hydroxybenzotriazole were added thereto and the resulting mixture was stirred at room temperature for 30 minutes. After blowing ammonia gas thereinto, the reaction mixture was distributed into an aqueous solution of sodium bicarbonate and ethyl acetate. The organic layer was extracted, washed with water and dried over anhydrous sodium sulfate. After distilling off the solvent under reduced pressure, the crystals thus precipitated were filtered. Further, the aqueous layer was acidified and the starting materials were recovered. After repeating the above-mentioned procedures, the title compound (620 mg in total) was obtained as yellow crystals.

Provenance & Evidence