Diethyl Malonate → Diethyl 5-(dimethylamino)-1,3-dithiane-2,2-dicarboxylate

Participants

Reaction Steps

To 20 ml of chloroform were added 1.6 g (0.01 mole) of diethyl malonate and 4.3 g (0.01 mole) of 1,3-bis(benzenesulfonylthio)-2-(N,N-dimethylamino)propane, and then 2.1 g (0.02 mole) of triethylamine was added thereto at room temperature. After completion of addition, the reaction was allowed to proceed at 40° C. for 4 hours. The reaction mixture was washed with two 20-ml portions of water, dried over anhydrous sodium sulfate and concentrated to dryness. The residue was heated in 20 ml of ether-hexane (1:1) for dissolution and the solution was allowed to stand in the cold overnight. The resulting crystalline precipitate was collected by filtration to give 2.7 g (90%) of 2,2-diethoxycarbonyl-5-(N,N-dimethylamino)-1,3-dithiane as light-yellow crystals melting at 38°-39° C.

Provenance & Evidence