Dimethylformamide → 5-Bromo-2-formylthiophene-3-carboxylic acid

Under a nitrogen atmosphere, 5-bromo-3-thiophenecarboxylic acid (12 g, 58 mmol) was added to THF (300 ml), and LDA (174 mmol, 232 ml, 0.75 M) was slowly dropped at −78° C. Then, the mixture was stirred for two hours at −30° C., and DMF was slowly dropped at −78° C. Then, water was added to the reaction solution. The reaction solution was then extracted with ethyl acetate, and an organic layer was washed with a saturated saline solution and water. The organic layer was dried with anhydrous magnesium sulfate, and, after filtration, the solvent was distilled off under reduced pressure. With this, a target substance was obtained as a solid (95% yield, crude product). 1H-NMR (400 MHZ, CDCl3, TMS) δ 10.44 (s, 1 H), 7.63 (s, 1 H)

1. additionwas slowly dropped at −78° C
2. extractionThe reaction solution was then extracted with ethyl acetate
3. washan organic layer was washed with a saturated saline solution and water
4. dry with materialThe organic layer was dried with anhydrous magnesium sulfate
5. filtrationafter filtration
6. distillationthe solvent was distilled off under reduced pressure
7. customWith this, a target substance was obtained as a solid (95% yield, crude product)

ORDレコード

ord-7d1fd3878b79454ea0308b6297c86e8f

出典データセット

uspto-grants-2016_04

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US09312491B2