1-Bromo-2-methylpropane → Diethyl isobutylmalonate

Beteiligte Stoffe

Reaktionsschritte

To a solution of NaOEt prepared by dissolving 5.75 g (0.25 mol) of Na in 150 mL of absolute EtOH was added 39 mL (0.250 mol) of diethyl malonate with cooling in a water bath under N2. To the resulting solution was added 24 mL (0.250 mol) of isobutyl bromide. The mixture was refluxed under N2 for 14 hours. The ethanol was evaporated under reduced pressure and the residue was partitioned between CHCl3 and water. The aqueous Na2SO4 and evaporated. The residue was distilled under reduced pressure to give 47.2 g (0.219 mol, 88% of diethyl isobutylmalonate as a colorless liquid. Characteristic analytical data are as follows: bp 127°-135° C. (25 mm Hg); 1H NMR (300 MHz, CDCL3) δ4.20 (q, J=7 Hz, 4H), 3,41 (t, J=8 Hz, 1H), 1.80 (t, J=7 Hz, 2 H), 1.57 (m, 1H), 1.27 (t, J=8 Hz, 6H), 0.92 (d, J=7 Hz, 6H).

Herkunft & Nachweise