Carbon Dioxide → 5-Bromothiophene-2-carboxylic acid

Temperature

-78 °C

THF (50 mL) was added via cannula to a flame-dried 100 mL Schlenk flask. 2,5-dibromothiophene (10 mmol, 2.42 g) was added via syringe. Reaction vessel was cooled to −78° C. and n-butyllithium (1.61M solution in hexanes, 11 mmol, 6.8 mL) was added dropwise over 5 minutes. The solution was allowed to stir at −78° C. for 1 hr. Dry ice (approx. 50 g) was added to the reaction mixture, and was allowed to stir and return to room temperature for 18 hrs. under nitrogen. The light gray suspension was filtered and the white solid was stirred in 2M HCl for 1 hr. The suspension was filtered to yield a white solid (5.7 mmol, 1.2 g, 57%). 1H NMR (400 MHz, CDCl3) δ: 11.45 (br s, 1H), 7.64 (d, 1H, J=4.0 Hz), 7.11 (dd, 1H, J=4.0 Hz).

1. customReaction vessel
2. stirringto stir
3. waitreturn to room temperature for 18 hrs
4. filtrationThe light gray suspension was filtered
5. stirringthe white solid was stirred in 2M HCl for 1 hr
6. filtrationThe suspension was filtered

ORD record

ord-34f37af4a65a4a4ea0816c6743d151af

Source dataset

uspto-grants-2016_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09234003B2