Hydrochloric Acid → 4-Bromofuran-2-carboxylic acid

A mixture of 4,5-dibromo-furan-2-carboxylic acid 22a (5.5 g, 20.3 mmol) and 18 mL of ammonium hydroxide was added to 63 mL of water followed by addition of zinc powder (1.46 g, 22.33 mmol). Upon completion of the addition, the reaction mixture was stirred at room temperature for 6 hours. The mixture was adjusted to pH 3 with 1 M hydrochloric acid to form a great quantity of precipitates. The mixture was filtered and the filter cake was washed with n-hexane (15 mL×4) and dried to obtain the title compound 4-bromo-furan-2-carboxylic acid 22b (3.2 g, yield 83.1%) as a white solid.

1. additionUpon completion of the addition
2. customto form a great quantity
3. customof precipitates
4. filtrationThe mixture was filtered
5. washthe filter cake was washed with n-hexane (15 mL×4)
6. customdried

ORD record

ord-da297a649124435799ac7206f0ba7e33

Source dataset

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08642637B2