Hydrochloric Acid → 2-methyl-4-phenyl-1,3-thiazole-5-carboxylic Acid

Temperature

80 °C

To a solution of ethanethioamide (80.0 g, 1.06 mol) in EtOH (600 mL), was added ethyl 2-chloro-3-oxo-3-phenylpropanoate (141.5 g, 0.64 mol), which was prepared by published procedure in M. Altuna-Urquijo, et al.; Tetrahedron; 65; 2009; 975-984, and the mixture was stirred at 80° C. for 2 h. The reaction mixture was allowed to cool to 50° C., 8N aqueous sodium hydroxide solution (120 mL) was added, and the mixture was stirred 80° C. for 2 h. The reaction mixture was allowed to cool to 50° C., 8N aqueous sodium hydroxide solution (240 mL) was added, and the mixture was stirred 80° C. for 1 h. The reaction mixture was allowed to cool to 0° C., and was then neutralized by the addition of 6N hydrochloric acid (400 mL). The mixture was stirred at rt for 12 h and the resulting precipitate was collected by filtration and washed with water, EtOH and diethyl ether sequentially to give the title compound (105.6 g, 75%) as a white solid.

1. customwas prepared by published procedure in M
2. temperatureto cool to 50° C.
3. stirringthe mixture was stirred 80° C. for 2 h
4. temperatureto cool to 50° C.
5. stirringthe mixture was stirred 80° C. for 1 h
6. temperatureto cool to 0° C.
7. stirringThe mixture was stirred at rt for 12 h
8. filtrationthe resulting precipitate was collected by filtration
9. washwashed with water, EtOH and diethyl ether sequentially

ORD record

ord-7d697ebbdda2437d8b958bb07889c058

Source dataset

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09139589B2