反应详情

To a solution of 4,-methylbiphenyl-2-carboxylic acid (6.4 g) in tetrahydrofuran (50 ml) were added N,N-dimethylformamide (two drops) and oxalyl chloride (4.4 g). The mixture was stirred for 16 hours at room temperature. The solvent was evaporated to dryness under reduced pressure to give an oil, which was added dropwise to a solution of hydrazine monohydrate (7.5 g) in tetrahydrofuran (50 ml) with stirring, followed by stirring for further 6 hours. The reaction mixture was diluted with water, which was extracted with ethyl acetate. The extract was washed with water and dried. The solvent was evaporated to dryness under reduced pressure. The residue was purified by column chromatography on silica gel to give crude crystals. Recrystallization from chloroform-isopropyl ether afforded the title compound as colorless needles (4.3 g, 63%), m.p.98°-99° C.

1. customThe solvent was evaporated to dryness under reduced pressure
2. customto give an oil, which
3. stirringwith stirring
4. stirringby stirring for further 6 hours
5. extractionwas extracted with ethyl acetate
6. washThe extract was washed with water
7. customdried
8. customThe solvent was evaporated to dryness under reduced pressure
9. customThe residue was purified by column chromatography on silica gel
10. customto give crude crystals
11. customRecrystallization from chloroform-isopropyl ether