Trifluoroacetic acid → Methyl 1,3-thiazole-4-carboxylate

2-((S)-2-{2-tert-Butoxycarbonylamino-2-[4-(2-methoxy-ethoxy)-phenyl]-acetylamino}-3-phenyl-propionylamino)-thiazole-4-carboxylic acid methyl ester (a mixture of two epimers, R/S=85:15) (0.21 g, 0.343 mmol) was dissolved into dry dichloromethane (20 mL) and trifluoroacetic acid (2 mL, 26 mmol) was added. The reaction mixture was stirred at room temperature for 1 hour. The mixture was concentrated to dryness. The residue was cooled in an ice bath, then neutralized with saturated aqueous sodium bicarbonate solution. The mixture was extracted with ethyl acetate. The organic layer was separated, dried over sodium sulfate, and concentrated to give crude 2-((S)-2A2-amino-2-[4-(2-methoxy-ethoxy)-phenyl]-acetylamino}-3-phenyl-propionylamino)-thiazole-4-carboxylic acid methyl ester as a white foam (a mixture of two epimers, R/S=85:15) (0.16 g, 91%).

1. additionwas added
2. concentrationThe mixture was concentrated to dryness
3. temperatureThe residue was cooled in an ice bath
4. extractionThe mixture was extracted with ethyl acetate
5. customThe organic layer was separated
6. dry with materialdried over sodium sulfate
7. concentrationconcentrated

ORD-Eintrag

ord-e1819b5a79f84755a4ffc697ef48f83a

Quelldatensatz

uspto-grants-2008_05

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07371869B2