反应详情

A mixture of methyl 2-bromo-4-methylpentanoate (V, Example 3, 14.6 g.) and ethylenediamine (VI, 12.5 g.) in ethanol (250 ml.) is stirred at 20°-25° for 20 hours. The ethanol is removed under reduced pressure and the residual oil is partitioned between chloroform and aqueous sodium bicarbonate. The chloroform layer is separated and the chloroform is removed under reduced pressure to give an oil which is refluxed in DMF (20 ml.) for one hour. After removal of the DMF the residue is column chromatographed on silica gel eluting with chloroform-methanol (99/5). Appropriate fractions are pooled and concentrated to give a residue which is dissolved in ethyl acetate (150 ml.) and decolorized with charcoal. Crystallization from ethyl acetate-SSB gives an oily solid which upon crystallization from ethyl acetate-SSB gives the title compound, m.p. 75°-77°.

1. customThe ethanol is removed under reduced pressure
2. customthe residual oil is partitioned between chloroform and aqueous sodium bicarbonate
3. customThe chloroform layer is separated
4. customthe chloroform is removed under reduced pressure
5. customto give an oil which
6. customAfter removal of the DMF the residue
7. customchromatographed on silica gel eluting with chloroform-methanol (99/5)
8. concentrationconcentrated
9. customto give a residue which
10. customCrystallization from ethyl acetate-SSB
11. customgives an oily solid which
12. customupon crystallization from ethyl acetate-SSB