Triethylamine → Methyl 5-(4-fluorophenyl)-1,2,3-thiadiazole-4-carboxylate

Temperatur

0 °C

A mixture of methyl 4-fluorobenzoylacetate (3.92 g), p-toluenesulfonyl azide (4.00 g), triethylamine (2.02 g) and acetonitrile (30 ml) was stirred at 0° C. for 1 hr. The reaction mixture was poured into water and extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate and concentrated to give a yellow oil. The Lawesson's reagent (8.10 g) and tetrahydrofuran (50 ml) were added to this yellow oil and the mixture was heated under reflux for 16 hrs. The reaction mixture was concentrated, and the residue was purified by silica gel column chromatography to give methyl 5-(4-fluorophenyl)-1,2,3-thiadiazole-4-carboxylate (1.95 g, yield 41%) as colorless crystals from a fraction eluted with ethyl acetate-hexane (1:3, v/v).

1. extractionextracted with ethyl acetate
2. washThe organic layer was washed with saturated brine
3. dry with materialdried over anhydrous magnesium sulfate
4. concentrationconcentrated
5. customto give a yellow oil
6. temperaturethe mixture was heated
7. temperatureunder reflux for 16 hrs
8. concentrationThe reaction mixture was concentrated
9. customthe residue was purified by silica gel column chromatography

ORD-Eintrag

ord-51cc9f5cc6e04895a44af5f42d9f0f93

Quelldatensatz

uspto-grants-2008_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07423159B2