反应详情

The procedure is as in Example 7, but starting with 5-hydroxy-6-(7-chloro-1,8-naphthyridin-2-yl)-7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazine (6.3 g) in methylene chloride (80 cc), triethylamine (5.05 g), methacryloyl chloride (3.14 g) and 4-dimethylaminopyridine (50 mg). The residue obtained is purified by recrystallization in acetonitrile followed by chromatography on neutral alumina (50 g) contained in a column 1.5 cm in diameter, eluting with methylene chloride and collecting 15-cc fractions. Fractions 12 to 34 are combined and concentrated to dryness under reduced pressure (2.7 kPa) at 40° C. 6-(7-Chloro-1,8-naphthyridin-2yl)-7-oxo-6,7-dihydro-5H-pyrrolo [3,4-b]-pyrazin-5yl methacrylate (1.4 g), m.p. 255° C., is thereby obtained.

1. customThe residue obtained
2. customis purified by recrystallization in acetonitrile
3. washeluting with methylene chloride
4. customcollecting 15-cc fractions
5. concentrationconcentrated to dryness under reduced pressure (2.7 kPa) at 40° C