Diethyl Malonate → Diethyl 2-(1-Bromo-2-naphthylmethyl)malonate

Beteiligte Stoffe

Reaktionsschritte

To a solution of NaOEt prepared from 9.66 g of sodium and 210 mL of dry EtOH was added 63.76 mL of diethyl malonate and the reaction mixture refluxed for 2 h. To the resulting yellow solution was added in small portions 126 g of 1-bromo-2-bromomethylnaphthalene and the reaction mixture refluxed for 16 h. Distillation of ethanol from an oil bath (100°-110° C.) through a simple Claisen head gave a yellow suspension, to which was added 350 mL of CH2Cl2 and 350 mL of H2O. The aqueous layer was extracted twice with 120-mL portions of CH2Cl2, and the combined organic layer was washed three times with 100-mL portion of H2O, dried (MgSO4) and evaporated to give 152 g (95.6%) of the ester as a yellow solid, mp 60°-65° C. Recrystallization from acetic acid gave 137 g (86.2%) of the pure diester as a colorless solid, mp 77°-79° C.

Herkunft & Nachweise