Lithium Hydroxide → 3-Hydroxythiophene-2-carboxylic acid

Temperature

22 °C

10.0 g of methyl 3-hydroxy-thiophene-2-carboxylate were dissolved in a mixture of 90 ml of tetrahydrofuran (THF) and 90 ml of methanol, and a solution of 25.2 g of lithium hydroxide in 25 ml of water was added. The reaction mixture was stirred at 22° C. for 18 h and then heated at 55° C. for 6 h. The reaction mixture was concentrated to 50 ml in a rotary evaporator, acidified to pH=1 with 2 molar hydrochloric acid and extracted 3 times with 50 ml of t-butyl methyl ether each time. The combined organic phases were dried over magnesium sulfate and concentrated.

1. temperatureheated at 55° C. for 6 h
2. concentrationThe reaction mixture was concentrated to 50 ml in a rotary evaporator
3. extractionextracted 3 times with 50 ml of t-butyl methyl ether each time
4. dry with materialThe combined organic phases were dried over magnesium sulfate
5. concentrationconcentrated

ORD record

ord-46e56409fa814a3c9a6cc09c14027afa

Source dataset

uspto-grants-2010_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07666848B2