Tetrahydrofuran → Ethyl 4-[1-[(10-(methoxymethyl)-10H-pyrazino[2,3-b][1,4]benzothiazin-8-ylmethyl]carbamoyl]piperidin-4-yl]-2-methylbutanoate

To a solution of 0.7 g of 10H-pyrazino[2,3-b][1,4]benzothiazine-8-acetic acid in tetrahydrofuran (50 ml) were added 0.35 ml of triethylamine and 0.55 ml of diphenyl phosphate azide and the resulting mixture was stirred at room temperature for 3 hours. Next, it was heated under reflux for 1.5 hours. After adding 0.55 g of ethyl 4-(piperidin-4-yl)-2-methylbutanoate, the resulting mixture was reacted at room temperature for 1 hour. After adding ethyl acetate, the reaction mixture was washed with water and dried over anhydrous magnesium sulfate. After distilling off the solvent under reduced pressure, the residue was purified by silica gel column chromatography (eluted with dichloromethane/methanol) to thereby give 0.66 g of the title compound as a yellow oily substance.

1. temperatureNext, it was heated
2. temperatureunder reflux for 1.5 hours
3. customthe resulting mixture was reacted at room temperature for 1 hour
4. washthe reaction mixture was washed with water
5. dry with materialdried over anhydrous magnesium sulfate
6. distillationAfter distilling off the solvent under reduced pressure
7. customthe residue was purified by silica gel column chromatography (eluted with dichloromethane/methanol)

ORD record

ord-e7bbc59923dd46089f7334316f7b69c9

Source dataset

uspto-grants-2003_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06518423B1