2,6-Lutidine → Ethyl 2-(5-methyl-1,2-oxazol-3-yl)-1,3-thiazole-4-carboxylate

Temperatur

55 °C

5-Methyl-isoxazole-3-carbothioamide (1.0 g, 7.0 mmol) was dissolved in acetone (16 mL) and treated with ethyl bromopyruvate (1 mL, 1 equivalent) and 3.9 g of powdered 3 A molecular sieves. The reaction was stirred at 55° C. under a nitrogen atmosphere for 18 h. The mixture was filtered and evaporated to give 1.06 g of crude material. This material was dissolved in THF (25 mL), cooled to 0° C., and treated with 2,6-lutidine (1.5 mL, 3 equivalents). Trifluoroactetic acid (0.9 mL, 1.5 equivalents) was added and stirring was continued for 2 hrs under a nitrogen atmosphere. The reaction was poured into a 1 M solution of sodium bicarbonate and extracted twice with ethyl acetate (75 mL). The combined organic layers were washed with brine, dried over magnesium sulfate, filtered and the solvent was removed by evaporation. The crude material was purified using chloroform:ethyl acetate (1:1) to give 876 mg (53%) of the title compound.

1. filtrationThe mixture was filtered
2. customevaporated
3. customto give 1.06 g of crude material
4. temperaturecooled to 0° C.
5. stirringstirring
6. waitwas continued for 2 hrs under a nitrogen atmosphere
7. extractionextracted twice with ethyl acetate (75 mL)
8. washThe combined organic layers were washed with brine
9. dry with materialdried over magnesium sulfate
10. filtrationfiltered
11. customthe solvent was removed by evaporation
12. customThe crude material was purified

ORD-Eintrag

ord-6e83e61dad6547e4a775f623a396ba02

Quelldatensatz

uspto-grants-2010_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07696226B2