Hydrochloric Acid → 2-Methyl-3-furoic acid

To a stirred solution of water (400 mL) and conc. hydrochloric acid (40 mL) is added chloroacetaldehyde-dimethylacetal (300 g) and brought to reflux. The homogenous solution was then added to a stirred cooled solution of ethyl acetoacetate (260 g. 2 mol) in pyridine (500 mL). This reaction mixture was allowed to stir overnight at ambient temperature. The lower layer of the reaction mixture was then removed and combined with the methylene chloride (2×100 mL) extract of the upper layer after dilution with an equal volume of water. The combined organics were washed with 1N HCl (200 mL), and evaporation of the solvent left the crude ester. Hydrolysis of this ester was accomplished by refluxing for 1 hour in ethanol (100 mL) and sodium hydroxide (50 g) in water (700 mL). The reaction mixture was then poured into water/ice (3 L) and acidified with hydrochloric acid to give a cream precipitate which was collected on a filter, washed with water and dried, to produce 180 g of 2-methyl-3-furoic acid, m.p. 105-106° C.

1. temperatureto reflux
2. additionThe homogenous solution was then added to a stirred
3. customThe lower layer of the reaction mixture was then removed
4. extractionextract of the upper layer after dilution with an equal volume of water
5. washThe combined organics were washed with 1N HCl (200 mL), and evaporation of the solvent
6. waitleft the crude ester
7. customHydrolysis of this ester
8. customto give a cream precipitate which
9. customwas collected on a filter
10. washwashed with water
11. customdried

ORD record

ord-129d71203cdd452eb8af90c6b045ba14

Source dataset

uspto-grants-1999_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05914351