Dimethylformamide → HCID 84819473, compound

Temperature

-78 °C

To a solution of (i-Pr)2NH (1.09 g, 10.8 mmol) in anhydrous THF (15 mL) was added dropwise n-BuLi (5.0 mL, 12.5 mmol, 2.5M in hexane) at −30° C. The mixture was stirred at the same temperature for 0.5 h. Then, the mixture was cooled to −78° C. and the solution of 4-bromothiophene-3-carboxylic acid from example 1.1 (1.0 g, 4.85 mmol) and HMPA (0.17 g, 0.95 mmol) in anhydrous THF (20 mL) was added slowly. The mixture was stirred at the same temperature for 1 h, anhydrous DMF (0.6 g, 8.22 mmol) was added dropwise into the stirring mixture at −78° C. The reaction mixture was stirred for another 45 min at room temperature and then quenched with water. The aqueous layer was acidified with 5% aq. HCl to pH 1-2, the precipitate was collected by filtration, the filtrate was extracted with DCM (3×50 mL). The organic layers were dried over Na2SO4 and concentrated under reduced pressure. The crude product was washed with CH2Cl2 to give the title product (0.68 g, 60.2%) as a solid.

1. stirringThe mixture was stirred at the same temperature for 1 h
2. stirringThe reaction mixture was stirred for another 45 min at room temperature
3. customquenched with water
4. filtrationthe precipitate was collected by filtration
5. extractionthe filtrate was extracted with DCM (3×50 mL)
6. dry with materialThe organic layers were dried over Na2SO4
7. concentrationconcentrated under reduced pressure
8. washThe crude product was washed with CH2Cl2

ORD record

ord-bc4f7c4fa76946b187c8330539948ed8

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09273068B2