Formamide → HCID 21290688, Verbindung
Reaktionsgleichung
S(=O)(=O)(O)O.C([NH2:8])=O.[Cl:9][C:10]1[CH:27]=[CH:26][C:13]([C:14]([O:16][CH:17]([C:23](=O)[CH3:24])[C:18]([O:20][CH2:21][CH3:22])=[O:19])=O)=[CH:12][CH:11]=1>>[Cl:9][C:10]1[CH:27]=[CH:26][C:13]([C:14]2[O:16][C:17]([C:18]([O:20][CH2:21][CH3:22])=[O:19])=[C:23]([CH3:24])[N:8]=2)=[CH:12][CH:11]=1Komponenten
4
Reaktionsbedingungen
- Temperatur
- 140 °C
Versuchsvorschrift
19.6 g (0.2 mol) of concentrated sulphuric acid were added dropwise during 10 minutes to 90 g (2 mol) of formamide, the temperature of the solution being held below 10° C. by external cooling, 26.8 g (0.09 mol) of ethyl 2-(4-chlorobenzoyloxy)-3-oxo-butyrate were added and the stirred solution was heated at 140° C. for 2 hours. The cooled suspension was partitioned between 400 ml of water and 300 ml of diethyl ether. The organic phase was washed twice with 200 ml of 1N hydrochloric acid each time and once with 200 ml of water and then filtered to remove suspended solids. The organic phase was dried over magnesium sulphate, filtered and evaporated. The residue was purified by chromatography on silica gel using 20% by volume ethyl acetate in hexane for the elution. After evaporation of the eluate there were obtained 13.3 g (50%) of ethyl 2-(4-chlorophenyl)-4-methyl-5-oxazolecarboxylate of melting point 80°-81° C.