2-Oxobutanoic Acid → HCID 67017140, compound

Temperature

0 °C

A RBF was charged with 2-oxobutanoic acid (2.50 g, 24.5 mmol) and 3.2 mL of water and the mixture was cooled to 0° C. The acid was neutralized by slow addition of 20% aqueous KOH. 3′-chloroacetophenone (3.79 g, 24.5 mmol) was added, followed by a 1.3 M solution of KOH (2.20 g, 39.2 mmol) in MeOH. The reaction mixture was stirred at 0° C. for 48 h. The mixture was brought to pH 2 by dropwise addition of conc. H2SO4. The MeOH was removed in vacuo, and 25 mL of water was added. The heterogeneous mixture was filtered through Celite, and the filter cake was washed with water and CH2Cl2. The layers of the filtrate were separated, and the aqueous portion was extracted with additional CH2Cl2. The combined organics were dried with MgSO4, filtered and concentrated to a volume of ˜25 mL. Hexane was added until the mixture became cloudy, and upon standing a white crystalline solid formed. The mother liquor was decanted and the solids were washed with hexane and dried to provide 4-(3-chlorophenyl)-2-ethyl-2-hydroxy-4-oxobutanoic acid as a white crystalline solid. MS m/z=279 [M+Na]+. Calc'd for C12H13ClO4: 256.69.

1. customThe MeOH was removed in vacuo, and 25 mL of water
2. additionwas added
3. filtrationThe heterogeneous mixture was filtered through Celite
4. washthe filter cake was washed with water and CH2Cl2
5. customThe layers of the filtrate were separated
6. extractionthe aqueous portion was extracted with additional CH2Cl2
7. dry with materialThe combined organics were dried with MgSO4
8. filtrationfiltered
9. concentrationconcentrated to a volume of ˜25 mL
10. additionHexane was added until the mixture
11. customformed
12. customThe mother liquor was decanted
13. washthe solids were washed with hexane
14. customdried

ORD record

ord-ebdf80736e1640859396e8866de3af01

Source dataset

uspto-grants-2013_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08404694B2