Water → 5-Cyclopropylisoxazole-4-carboxylic acid

Temperature

60 °C

Methyl 3-cyclopropyl-3-oxopropanoate (0.28 g, 2 mmol) and 1,1-dimethoxy-N,N-dimethylmethanamine (0.24 g, 2 mmol) was mixed and heated for 20 h at 60° C. The bright yellow oil was dissolved in methanol (2 mL) and H2O (1 mL) and hydroxylamine hydrochloride (0.14 g, 2 mmol) was added, resulting in a pH of ca 5. The reaction was heated for 90 min at 60° C. The solvents were evaporated and the residue refluxed in acetic acid: conc. HCl (3+3 mL) for 4 h. The mixture was stored at room temperature for 2 days and the solid was filtered off and dried in vacuum to yield the title compound as a grey solid. This compound is also commercially available. 1H NMR (400 MHz, CHLOROFORM-D) δ ppm 1.18-1.28 (m, 2 H) 1.28-1.35 (m, 2 H) 2.78-2.90 (m, 1 H) 8.45 (s, 1 H)

1. customresulting in a pH of ca 5
2. temperatureThe reaction was heated for 90 min at 60° C
3. customThe solvents were evaporated
4. temperaturethe residue refluxed in acetic acid
5. waitThe mixture was stored at room temperature for 2 days
6. filtrationthe solid was filtered off
7. customdried in vacuum

ORD record

ord-02d248f9769f4867afc62d8805fb9133

Source dataset

uspto-grants-2010_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07666888B2