Diethyl Oxalate → HCID 86682306, compound

Participants

Reaction Steps

10.2 g of diisopropylamine (0.1 mol) were dissolved in 100 ml of dry THF under nitrogen and cooled in a freezing mixture. 40 ml n-butyllithium in hexane (2.5 M, 0.1 mol) were slowly added dropwise. When the addition was completed it was allowed to stir for 60 minutes and then 8.7 g N,N-dimethylacetamide (0.1 mol) were added dropwise. The reaction mixture was stirred for another 20 min in the freezing mixture. In a second flask, 43.7 g of diethyl oxalate (0.3 mol) in 50 ml of dry THF were cooled in a freezing mixture and the cooled reaction mixture was cannulated with stirring in small portions to it. It was left overnight under stirring to warm to room temperature. The THF was removed on a rotary evaporator and the residue was taken up in 80 ml half concentrated hydrochloric acid. The aqueous phase was extracted five times with 150 ml ethyl acetate, the combined organic phases dried over sodium sulfate and concentrated on a rotary evaporator to dryness. The excess diethyl oxalate was removed by distillation (2-3 mbar, 80° C.) and 17 g of crude product were obtained. 5.5 g product was obtained as white crystals with a melting point of 28° C. after crystallization from n-hexane.

Provenance & Evidence