1,4-Butanesultam → 4-Acetyl-5-[(1,1-Dioxido-1,2-thiazinan-2-yl)methyl]-1-(4-fluorobenzyl)-piperazin-2-one

Participants

Reaction Steps

A mixture of 4-acetyl-5-[(benzyloxy)methyl]-1-(4-fluorobenzyl)piperazin-2-one (6.5 g) and 20% Pd/C (1.4 g) in ethanol (175 mL) was shaken under an atmosphere of hydrogen (60 psi) at room temperature overnight. The product mixture was filtered through a pad of Celite, and concentrated under vacuum. Residual ethanol was removed by co-evaporation with toluene under vacuum (3×). The resultant alcohol was used without further purification. A mixture of the alcohol (1.0 g, 3.57 mmol), 1,2-thiazinane 1,1-dioxide (0.73, 5.4 mmol), and cyanomethylenetri-n-butylphosphorane (1.3 g, 5.4 mmol; [157141-27-0]) in benzene (20 mL) was purged with nitrogen and heated in a sealed tube at 100° C. overnight. The reaction mixture was concentrated under vacuum, and the residue was subjected to column chromatography on silica gel eluting with a mixture of 5% methanol in ethyl acetate. Collection and concentration of appropriate fractions provided the title compound.

Provenance & Evidence