Triethylamine → (E)-tert-butyl 4-(4-methoxy-4-oxobut-2-enoyl)piperazine-1-carboxylate

Participants

Reaction Steps

Mono methyl fumarate (650 mg, 5.0 mmol) was taken up in 10 mL of CH2Cl2 and oxalyl chloride (420 μL, 5.0 mmol) was added. After a few drops of DMF was added, the reaction mixture was stirred at room temperature until all gas evolution had ceased (1 h). This freshly prepared solution of acid chloride was then added dropwise at 0° C. to a solution containing Boc-piperazine (930 mg) and triethylamine (1.0 mL, 7.5 mmol) in 20 mL of CH2Cl2. The resulting reaction mixture was stirred at room temperature for 1 h and washed with brine. The organic layer was dried (Na2SO4) and concentrated under reduced pressure. Purification by chromatography (CH2Cl2) afforded 310 mg of (E)-tert-butyl 4-(4-methoxy-4-oxobut-2-enoyl)piperazine-1-carboxylate (21% yield).

Provenance & Evidence