反应详情

Into a solution of 40 g of lithium aluminum lithium hydride in tetrahydrofuran (1 l) was dropped a solution of 200 g of methyl 10H-pyrazino[2,3-b][1,4]benzothiazine-8-carboxylate in tetrahydrofuran (2.5 l) while maintaining the mixture at a temperature not exceeding 15° C. After continuing the reaction at 15° C. or below for 1 hour, 40 ml of water, 40 ml of a 15% aqueous solution of sodium hydroxide and 120 ml of water were successively added and the resulting mixture was stirred for an additional 1 hour. After filtering off the insoluble matter, the solvent was distilled off under reduced pressure to thereby give 125 g of the title compound as yellow crystals.

1. temperaturewhile maintaining the mixture at a temperature not
2. customexceeding 15° C
3. customthe reaction at 15° C. or below for 1 hour
4. filtrationAfter filtering off the insoluble matter
5. distillationthe solvent was distilled off under reduced pressure