Dichloromethane → Ethyl 5-methoxythiazole-2-carboxylate

Temperature

60 °C

A mixture of ethyl 2-(2-methoxy-2-oxoethylamino)-2-oxoacetate (1.00 g, 5.29 mmol) and phosphorus pentasulfide (1.29 g, 5.82 mmol) in chloroform (20 ml) was stirred at 60° C. for 7 h. To the cooled reaction mixture DCM (100 ml) was added and the mixture was washed with water (50 ml) and brine (50 ml). Organic phase was dried over Na2SO4 and evaporated. Evaporation residual was dissolved in dry MeCN (10 ml) and phosphorus pentoxide (0.75 g, 5.29 mml) was added and the mixture was heated to reflux for 4.5 h. To the cooled reaction mixture water (35 ml) was added and the mixture was extracted with EtOAc (3×50 ml). Combined organic fractions were dried over Na2SO4 and evaporated to give crude product, which was purified twice by CombiFlash (1st column: silica, eluent: 0-100% EtOAc in heptane; 2nd column: C-18, eluent: 0-100% MeCN in water) to yield 73 mg (7%) of the title compound. 1H-NMR (400 MHz; CDCl3): δ 1.42 (t, 3H), 4.01 (s, 3H), 4.43 (q, 2H), 7.30 (s, 1H).

1. additionwas added
2. washthe mixture was washed with water (50 ml) and brine (50 ml)
3. dry with materialOrganic phase was dried over Na2SO4
4. customevaporated
5. customEvaporation residual
6. dissolutionwas dissolved in dry MeCN (10 ml)
7. additionphosphorus pentoxide (0.75 g, 5.29 mml) was added
8. temperaturethe mixture was heated
9. temperatureto reflux for 4.5 h
10. customTo the cooled reaction mixture water (35 ml)
11. additionwas added
12. extractionthe mixture was extracted with EtOAc (3×50 ml)
13. dry with materialCombined organic fractions were dried over Na2SO4
14. customevaporated
15. customto give crude product, which
16. customwas purified twice by CombiFlash (1st column: silica, eluent: 0-100% EtOAc in heptane; 2nd column: C-18, eluent: 0-100% MeCN in water)

ORD record

ord-4263836c96bb4f2d8a4337928e947507

Source dataset

uspto-grants-2015_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08975254B2