Water → Ethyl 2-(2-aminothiazol-5-ylthio)acetate

Temperature

0 °C

5-Bromo-2-aminothiazole (25 g, 96 mmol) and K2CO3 (26.5 g, 192 mmol) was suspended in DMF (50 mL) and stirred to 0° C. Ethyl thioglycolate (11.6 mL, 96 mmol) was added during 10 min. The reaction mixture was allowed to reach room temperature and stirred for further 13H. Addition of water (100 mL) and EtOAc (150 mL). Separation of the organic phase followed by extraction of the aqueous phase with EtOAc (2×100 mL). The combined organic phases were washed with aqueous NaHCO3 (2000 mL), brine (2×200 mL) and dried (MgSO4), filtered and evaporated. The crude product was dissolved in a small amount of DCM and purified by flash chromatography (ISCO 330 g silica column, eluent A: heptane/B: 2% TEA in EtOAc. Gradient from 30% B->100% B.) to give 50-65% pure (2-aminothiazol-5-ylsulfanyl)acetic acid ethyl ester as a dark red-brown oil.

1. customto reach room temperature
2. stirringstirred for further 13H
3. customSeparation of the organic phase
4. extractionfollowed by extraction of the aqueous phase with EtOAc (2×100 mL)
5. washThe combined organic phases were washed with aqueous NaHCO3 (2000 mL), brine (2×200 mL)
6. dry with materialdried (MgSO4)
7. filtrationfiltered
8. customevaporated
9. dissolutionThe crude product was dissolved in a small amount of DCM
10. custompurified by flash chromatography (ISCO 330 g silica column, eluent A: heptane/B: 2% TEA in EtOAc. Gradient from 30% B->100% B.)

ORD record

ord-d71a42c907714e48a380cb3718922cbb

Source dataset

uspto-grants-2011_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07884210B2