反应详情

A mixture of ethyl 2,4-dibenzyloxyphenoxyacetate (2 g), 10% w/v potassium hydroxide (10 mL) and methanol (50 mL) is stirred at ambient temperature for 1 hour. The reaction is concentrated in vacuo and acidified with 1 N HCL then extracted with ethyl acetate (2×100 mL). The organic layer is washed with water (2×100 mL), dried over magnesium sulphate, filtered and concentrated in vacuo to give a white powder. Recrystallisation from ethyl acetate/cyclohexane affords 2,4-dibenzyloxyphenoxyacetic acid (0.4 g) as a white solid, m.p. 72° C. [Elemental Analysis:- C, 72.4, H, 5.50% Calculated for C, 72.5H, 5.53%].

1. concentrationThe reaction is concentrated in vacuo
2. extractionextracted with ethyl acetate (2×100 mL)
3. washThe organic layer is washed with water (2×100 mL)
4. dry with materialdried over magnesium sulphate
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customto give a white powder
8. customRecrystallisation from ethyl acetate/cyclohexane