反应详情

1,1'-Carbonyl diimidazole (0.8 g, 0.005 mole) is added in one portion to a stirred 0° C. solution of 3,5-bis(1,1-dimethylethyl)-4-hydroxybenzoic acid hydrazide (1.0 g, 0.004 mole) and triethylamine (0.6 ml, 0.004 mole) in tetrahydrofuran (12 ml). After 18 hours the mixture is concentrated in vacuo and the residue dissolved in ether. The solution is washed with aqueous 2M HC, saturated aqueous NaHCO3, saturated aqueous NaCl, and dried over MgSO4. Filtered and concentrated in vacuo to obtain a residue which is purified by flash chromatography using 10% ethyl acetate/hexane eluent. Recrystallize from ethyl acetate/hexane to obtain 0.6 g (1.1 g theor., 55%) 5-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-1,3,4-oxadiazol-2(3H)-one, mp 246° C.

1. concentrationAfter 18 hours the mixture is concentrated in vacuo
2. dissolutionthe residue dissolved in ether
3. washThe solution is washed with aqueous 2M HC, saturated aqueous NaHCO3, saturated aqueous NaCl
4. dry with materialdried over MgSO4
5. filtrationFiltered
6. concentrationconcentrated in vacuo
7. customto obtain a residue which
8. customis purified by flash chromatography
9. customRecrystallize from ethyl acetate/hexane