Carbon Dioxide → beta-Phenylisovaleric acid

Beteiligte Stoffe

Reaktionsschritte

Magnesium (36.9 g, 1.52 mol, 50-150 mesh), neophylchloride (2.0 g, 0.01 mol) and tetrahydrofuran (40 ml) were placed in a flask under an atmosphere of argon. A Grignard reaction was then started with 1,2-dibromoethane (0.2 ml) and tert.-butyl methyl ether (MTBE, 50 ml) was subsequently added while maintaining reflux. Neophylchloride (258 g, 1.53 mol) dissolved in MTBE (400 ml) was then added at 48° C. over a period of 5.5 h. After 1.7 h stirring at the same temperature, the reaction mixture was diluted with MTBE (500 ml). Dried CO2 was then introduced above the surface at a temperature of 35° C. (ice cooling) for 18 min and directly into the solution for 5 min. The mixture was then acidified with HCl 16% and the organic phase was extracted with NaOH 32% (160 ml). The alkaline solution was first washed with MTBE and then again acidified with HCl 16%. Extraction with MTBE and evaporation of the solvent gave 3-Methyl-3-phenyl-butanoic acid (247.2 g).

Herkunft & Nachweise