反应详情

A mixture of xanthene-9-spiro-4'-tetrahydropyran-2'-one (0.5 g.) and methylamine (5 ml.) is heated at 250° C. for 4 hours in a steel bomb. The gummy residue (0.52 g.) is chromatographed on silica gel, eluting with increasing concentrations of chloroform in light petroleum (b.p. 60°-80° C.). Elution with 25% chloroform in light petroleum gives, on evaporation of the solvent, a solid residue which is recrystallised from ethanol to give 1'-methylxanthene-9-spiro-4'-piperidin-2'-one, m.p. 158°-159° C.

1. customThe gummy residue (0.52 g.) is chromatographed on silica gel
2. washeluting
3. temperaturewith increasing concentrations of chloroform in light petroleum (b.p. 60°-80° C.)
4. washElution with 25% chloroform in light petroleum
5. customgives, on evaporation of the solvent
6. customa solid residue which is recrystallised from ethanol