反应详情

1,1-Dimethylethyl 2-[3,5-bis(1,1-dimethylethyl)-4-hydroxybenzoyl]hydrazine carboxylic acid (4.0 g , 0.011 mole) in tetrahydrofuran (100 ml) is treated with a mixture of water (12 ml) and concentrated hydrochloric acid (30 ml). The resulting mixture is heated on a steam-bath. After 20 minutes the mixture is stripped of volatiles under reduced pressure. The residue is dissolved in water (100 ml) and treated with 1M NaOH until the solution is slightly basic. The product is extracted into ether (600 ml) and the organic layer is washed with saturated aqueous NaCl and dried over MgSO4. Filtration and concentration provides a solid which is recrystallized from isopropyl ether/hexane to yield 1.9 g (2.9 g theor., 66%) of 3,5-bis(1,1-dimethylethyl)-4-hydroxybenzoic acid, hydrazide, mp 187°-188° C.

1. temperatureThe resulting mixture is heated on a steam-bath
2. extractionThe product is extracted into ether (600 ml)
3. washthe organic layer is washed with saturated aqueous NaCl
4. dry with materialdried over MgSO4
5. filtrationFiltration and concentration
6. customprovides a solid which
7. customis recrystallized from isopropyl ether/hexane