反应详情

To trifluoroacetic acid (50 ml.) under a nitrogen atmosphere was added 2.27 g. (0.06 mole) of NaBH4 pellets over a period of 30 minutes at 5°. A solution of ethyl 2,3-dichloro-4-(4'-hydroxybenzoyl)phenoxyacetate (prepared as described in Example 1) (3 g., 0.0081 mole) in 30 ml. of methylene chloride was added dropwise at 15°-20° over a period of 20 minutes. The reaction mixture was stirred overnight at room temperature while the NaBH4 pellets slowly dissolved. At this time the reaction mixture was poured into water and the resulting solution extracted with methylene chloride. The organic extract was washed with aqueous NaCL and dried over MgSO4. Evaporation of the methylene chloride furnished a residue which was chromatographed on a silica gel column eluting with increasing amounts of methanol (MeOH) in CH2Cl2. There was obtained 2 g. of white solid, m.p. 102°-103°.

1. dissolutionslowly dissolved
2. extractionthe resulting solution extracted with methylene chloride
3. extractionThe organic extract
4. washwas washed with aqueous NaCL
5. dry with materialdried over MgSO4
6. customEvaporation of the methylene chloride
7. customfurnished a residue which
8. customwas chromatographed on a silica gel column
9. washeluting with increasing amounts of methanol (MeOH) in CH2Cl2
10. customThere was obtained 2 g