Lithium Hydroxide → 5-(Propan-2-yl)-1,3-thiazole-2-carboxylic acid

A solution of ethyl 5-isopropylthiazole-2-carboxylate (example 54, step a) (0.105 g) in methanol (5 mL) was treated with a solution of lithium hydroxide (0.025 g) in water (3 mL) and the resultant mixture was stirred vigorously at 20° C. for 2 hours. The methanol was evaporated off under reduced pressure and the residual aqueous solution was diluted with brine (10 mL). The aqueous layer was washed with ether, then cooled in an ice bath and acidified by dropwise addition of concentrated aqueous hydrochloric acid. The mixture was extracted twice with ethyl acetate. The combined ethyl acetate layers were washed with brine, dried over sodium sulphate, filtered and the solvent evaporated under reduced pressure to afford the subtitled compound. Yield 0.048 g.

1. customThe methanol was evaporated off under reduced pressure
2. additionthe residual aqueous solution was diluted with brine (10 mL)
3. washThe aqueous layer was washed with ether
4. temperaturecooled in an ice bath
5. additionacidified by dropwise addition of concentrated aqueous hydrochloric acid
6. extractionThe mixture was extracted twice with ethyl acetate
7. washThe combined ethyl acetate layers were washed with brine
8. dry with materialdried over sodium sulphate
9. filtrationfiltered
10. customthe solvent evaporated under reduced pressure

ORD record

ord-fe80f88b86c64954aef33ec4d2b780e3

Source dataset

uspto-grants-2012_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08148373B2