Dimethylformamide dimethyl acetal → HCID 22221428, compound

A mixture of methyl 4′-fluorobenzoylacetate (10.02 g) and N,N-dimethylformamide dimethylacetal (8.63 g) was refluxed for 1.5 hr. The reaction mixture was concentrated, and the residue was dissolved in ethanol (150 ml). To the obtained solution was added hydroxylamine hydrochloride (6.75 g) and the mixture was refluxed for 5 hr. The reaction mixture was concentrated, dilute hydrochloric acid was added to the residue, and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with saturated brine, dried (MgSO4) and concentrated. The residue was subjected to silica gel column chromatography, and methyl 5-(4-fluorophenyl)isoxazole-4-carboxylate (9.75 g, yield 91%) was obtained as colorless crystals from a fraction eluted with ethyl acetate-hexane (1:4, volume ratio). The crystals were recrystallized from ethyl acetate-hexane. melting point: 92–93° C.

1. temperaturewas refluxed for 1.5 hr
2. concentrationThe reaction mixture was concentrated
3. dissolutionthe residue was dissolved in ethanol (150 ml)
4. additionTo the obtained solution was added hydroxylamine hydrochloride (6.75 g)
5. temperaturethe mixture was refluxed for 5 hr
6. concentrationThe reaction mixture was concentrated
7. additiondilute hydrochloric acid was added to the residue
8. extractionthe mixture was extracted with ethyl acetate
9. washThe ethyl acetate layer was washed with saturated brine
10. dry with materialdried (MgSO4)
11. concentrationconcentrated

ORD record

ord-ddc5136ba82b46d8bb6bb5f5c69ac8a8

Source dataset

uspto-grants-2006_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07022725B2