Water → Ethyl 2-(pyridin-4-YL)thiazole-4-carboxylate

Temperatur

70 °C

A suspension of iso-thionicotinamide (5 g, 36.2 mmol) was dissolved in ethanol (90 mL) and treated with ethyl bromopyruvate (5 mL, 1 equivalent) and 20 g of powdered 3 A molecular sieves. The reaction was stirred at 70° C. under a nitrogen atmosphere for 48 h. The mixture was filtered and evaporated to give 12.5 g of crude material. This material was dissolved in THF (200 mL) and treated with 2,6-lutidine (17 mL, 4 equivalents). The reaction was cooled to 0° C. followed by the addition of trifluoroactetic acid (10.2 mL, 2 equivalents). Stirring was continued for 2 hrs under a nitrogen atmosphere. Water (200 mL) was added and the reaction was extracted twice with ethyl acetate (600 mL, 150 mL). The combined organic layers were washed with brined, 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 4.70 g (56%) of the title compound.

1. filtrationThe mixture was filtered
2. customevaporated
3. customto give 12.5 g of crude material
4. temperatureThe reaction was cooled to 0° C.
5. stirringStirring
6. waitwas continued for 2 hrs under a nitrogen atmosphere
7. extractionthe reaction was extracted twice with ethyl acetate (600 mL, 150 mL)
8. washThe combined organic layers were washed with brined,
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-9d29bb863dfb47bda5e3dffda225bd15

Quelldatensatz

uspto-grants-2010_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07696226B2