Ethyl Acetate → 1-(4,5,6,7-Tetrahydro-1,3-benzothiazol-2-yl)propan-2-one

Temperature

-78 °C

1.50 g (9.78 mmol) of the compound from example 18A are dissolved in 10 ml of abs. THF and, at −78° C., 4.31 ml (10.77 mmol) of n-butyllithium (2.5 M solution in hexane) are added dropwise. After stirring at −78° C. for 2 hours, 1.46 g (16.6 mmol) of ethyl acetate are added as solution in 5 ml of abs. THF. The mixture is stirred at −78° C. for 1 h and then warmed to room temperature. It is then hydrolyzed with sodium bicarbonate solution, and the mixture is extracted three times with diethyl ether. The combined organic phases are dried over magnesium sulfate, and the solvent is removed in a rotary evaporator. 1.60 g (67% of theory) of the title compound are obtained in 80% purity (LC-MS) and are employed without further purification.

1. stirringThe mixture is stirred at −78° C. for 1 h
2. temperaturewarmed to room temperature
3. extractionhydrolyzed with sodium bicarbonate solution, and the mixture is extracted three times with diethyl ether
4. dry with materialThe combined organic phases are dried over magnesium sulfate
5. customthe solvent is removed in a rotary evaporator

ORD record

ord-6e707ab94ee34ac6870677d6b625af14

Source dataset

uspto-grants-2013_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08404723B2