Reaktion #80972

Reaktionsgleichung

2-methylpropane-thioamide

ethyl bromopyruvate

MgSO4

→

desired compound

Ausbeute 86.4%

Ethyl 2-Isopropylthiazole-4-carboxylate

Ausbeute 86.4%

Lösungsmittel

acetone

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturheated
2. 2
   Temperaturat reflux for 2.5 h
3. 3
   Temperaturto cool
4. 4
   Filtrationfiltered
5. 5
   Einengenconcentrated in vacuo to an oil, which
6. 6
   Waschenwashed sequentially with aqueous NaHCO3 and brine
7. 7
   Trocknendried over Na2SO4
8. 8
   Einengenconcentrated
9. 9
   SonstigeThe residue was purified by chromatography on silica gel

Vorschrift

A solution of 2.35 g (23 mmol) of 2-methylpropane-thioamide and 2.89 ml (23 mmol) of ethyl bromopyruvate in 75 ml of acetone was treated with excess MgSO4 and heated at reflux for 2.5 h. The resulting mixture was allowed to cool, filtered, and concentrated in vacuo to an oil, which was taken up in chloroform, washed sequentially with aqueous NaHCO3 and brine, dried over Na2SO4, and concentrated. The residue was purified by chromatography on silica gel using chloroform as an eluent to provide 3.96 g (86%) of the desired compound, Rf 0.21 (chloroform) as an oil. 1H NMR (CDCl3) δ1.41 (t, J=8 Hz, 3H), 1.42 (d, J=7 Hz, 6H), 3.43 (heptet, J=7 Hz, 1H), 4.41 (q, J=8 Hz, 2H), 8.05 (s, 1H). Mass spectrum: (M+H)+ =200.

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