反应详情

A solution of the diester from preparation 9 (11.8 g,•47.0 mmol) and 2,2′-(1,4-phenylene)diacetic acid (15.73 g, 81.0 mmol) in ethanol (6.14 ml) and dioxan (75 ml) was treated dropwise with 12M hydrochloric acid (1.57 ml, 18.8 mmol). The reaction mixture was stirred at reflux for 18 hours before being allowed to cool and concentrated to low volume. The reaction mixture was diluted with toluene (125 ml) and the resulting slurry filtered. The filtrate was concentrated in vacuo and the residue taken up in water and basified with sodium bicarbonate until pH neutral. The mixture was diluted with ethyl acetate (200 ml) and the organic layer was separated and washed with sodium bicarbonate solution (5×30 ml) and sat. aq. sodium chloride (50 ml). The combined aqueous extracts were acidified to pH 3 with 6M hydrochloric acid and extracted with ether (3×30 ml). The organics were combined, dried (magnesium sulphate) and concentrated in vacuo. The residue was triturated with pentane giving the title compound as a colourless solid 10.8 g.

1. temperatureat reflux for 18 hours
2. temperatureto cool
3. concentrationconcentrated to low volume
4. additionThe reaction mixture was diluted with toluene (125 ml)
5. filtrationthe resulting slurry filtered
6. concentrationThe filtrate was concentrated in vacuo
7. additionThe mixture was diluted with ethyl acetate (200 ml)
8. customthe organic layer was separated
9. washwashed with sodium bicarbonate solution (5×30 ml) and sat. aq. sodium chloride (50 ml)
10. extractionextracted with ether (3×30 ml)
11. dry with materialdried (magnesium sulphate)
12. concentrationconcentrated in vacuo
13. customThe residue was triturated with pentane giving the title compound as a colourless solid 10.8 g