1,8-Diazabicyclo(5.4.0)undec-7-ene → 1,4-Bis(tert-butoxycarbonyl)-2-[3-(thien-2-yl)-2-propenyl]piperazine

Participants

Reaction Steps

In tetrahydrofuran (50 ml) was dissolved 1,4-bis(tert-butoxycarbonyl)-2-formylmethylpiperazine (1.01 g). Under ice cooling, a solution of [(thien-2-yl)methyl]phosphonium (1.62 g) in chloroform (100 ml) was added to the resulting solution, followed by the dropwise addition of 1,8-diazabicyclo[5.4.0]-7-undecene (620 μl). The resulting mixture was stirred at room temperature for 15 hours. The reaction mixture was distilled under reduced pressure. The residue was subjected to chromatography on a silica gel column (hexane:ethyl acetate=9:1 to 2:1), whereby the title compound (1.13 g) was obtained as a pale yellow oil.

Provenance & Evidence