Reaktion #2254152

Reaktionsgleichung

Ethyl 4-[2-(5-fluoropyridin-3-yl)-4-methyl-1,3-thiazol-5-yl]-2,4-dioxobutanoate

methylhydrazine

→

ethyl 3-[2-(5-fluoropyridin-3-yl)-4-methyl-1,3-thiazol-5-yl]-1-methyl-1H-pyrazole-5-carboxylate

Ausbeute 17.5%

Lösungsmittel

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturunder reflux for 2 b
2. 2
   SonstigeThe product formed
3. 3
   Filtrationwas filtered off with suction
4. 4
   Sonstigethe solvent of the filtrate was removed under reduced pressure
5. 5
   SonstigeThe residue was chromatographed on silica gel (cyclohexane/ethyl acetate eluent)

Vorschrift

Ethyl 4-[2-(5-fluoropyridin-3-yl)-4-methyl-1,3-thiazol-5-yl]-2,4-dioxobutanoate (6.9 g, 20.5 mmol) and methylhydrazine (0.65 g, 20.5 mmol) were heated in ethanol (250 ml) under reflux for 2 b. The product formed was filtered off with suction and the solvent of the filtrate was removed under reduced pressure. The residue was chromatographed on silica gel (cyclohexane/ethyl acetate eluent). This gave a total of 1.24 g (17% of theory) of ethyl 3-[2-(5-fluoropyridin-3-yl)-4-methyl-1,3-thiazol-5-yl]-1-methyl-1H-pyrazole-5-carboxylate. As a by-product, 4.8 g (67% of theory) of ethyl 5-[2-(5-fluoropyridin-3-yl)-4-methyl-1,3-thiazol-5-yl]-1-methyl-1H-pyrazole-3-carboxylate were obtained.

Quelle