Hydrochloric Acid → HCID 58478832, compound

Temperature

-50 °C

A solution of thiophene-3-carboxylic acid (1.00 g, 7.8 mmol) in THF (10 mL) is added dropwise to a cold (−80° C.) solution of lithium bistrimethylsilylamide (8.6 mL of a 2M solution in solvent) in THF (15 mL). The resulting pale yellow solution is warmed to −50° C. and is stirred at −50° C. for 1 hr during which time a white precipitate is formed. The reaction mixture is cooled to −80° C. and treated dropwise with propionaldehyde (1.2 mL, 16.6 mmol). The reaction mixture is warmed to −20° C. and stirred for 30 min. The reaction mixture is then poured into aqueous 2M HCl solution (120 mL). The resulting suspension is stirred at room temperature while a stream of air is blown into the reaction vessel to assist in the evaporation of THF. The white precipitate which forms is collected by filtration and dissolved in Dichloromethane (5 mL) and Et3N (5 mL). The reaction mixture is treated with p-toluenesulfonyl chloride (0.38 g, 2.0 mmol) and stirred overnight. The reaction mixture is treated with NaHCO3 solution and the organic phase is collected, dried over Na2SO4, filtered and concentrated to give the title compound (0.33 g, 25%).

1. customis formed
2. temperatureThe reaction mixture is cooled to −80° C.
3. temperatureThe reaction mixture is warmed to −20° C.
4. stirringstirred for 30 min
5. stirringThe resulting suspension is stirred at room temperature while a stream of air
6. customto assist in the evaporation of THF
7. filtrationThe white precipitate which forms is collected by filtration
8. dissolutiondissolved in Dichloromethane (5 mL)
9. stirringstirred overnight
10. customthe organic phase is collected
11. dry with materialdried over Na2SO4
12. filtrationfiltered
13. concentrationconcentrated

ORD record

ord-ec71c0e7c77a490f937fe2691edd0847

Source dataset

uspto-grants-2013_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08455535B2