反应详情

The furoylpiperazine of Example 1 was converted to the hydrobromide salt (m.p. 173°-175° C.). This salt (39.0 g) in 250 ml methyl alcohol and 9.0 g Raney nickel was hydrogenated at 3 atm. After uptake of H2 ceased, the catalyst was filtered, the solvent concentrated, and the residue crystallized from isopropyl alcohol to give 35.2 g. tetrahydrofuroylpiperazine HBr, m.p. 152°-156° C. This was suspended in 20 ml H2O. Then 10.5 g 50%, NaOH solution was added slowly followed by 2.0 g solid Na2CO3. This was extracted with 4×100 ml portions of warm CHCl3. The CHCl3 extractions were distilled to give 22.5 g tetrahydrofurolylpiperazine, b.p. 120°-125° C./0.2 mm Hg.

1. filtrationthe catalyst was filtered
2. concentrationthe solvent concentrated
3. customthe residue crystallized from isopropyl alcohol
4. customto give 35.2 g
5. extractionThis was extracted with 4×100 ml portions of warm CHCl3
6. extractionThe CHCl3 extractions
7. distillationwere distilled
8. customto give 22.5 g tetrahydrofurolylpiperazine, b.p. 120°-125° C./0.2 mm Hg