反应详情

5-Formyl-furan-2-carboxylic acid (1 g, 7.14 mmol) was treated in the same manner as described above for the synthesis of 3-pentylamino-phthalic acid dimethyl ester except the combined aqueous NaHCO3 extracts were washed with methylene chloride (1×70 ml) and the pH adjusted to 2-3 by dropwise addition of concentrated HCl. The mixture was then extracted with ethyl acetate (3×75 ml). The combined ethyl acetate extracts were washed with brine (1×100 ml), dried (magnesium sulfate), and filtered. The solvent was evaporated in vacuo to give 0.90 g product as an off-white solid: 1H NMR (CDCl3) δ 7.42-7.36 (m, 1H), 7.16 (d, J=3.5 Hz, 1H), 7.03-6.97 (m, 2H), 6.90 (dd, J=1.0 Hz and 7.3 Hz, 1H), 6.48 (d, J=3.5 Hz, 1H), 4.60 (d, J=5.2 Hz, 2H), 3.82 (s, 3H), 3.81 (s, 3H).

1. washwere washed with methylene chloride (1×70 ml)
2. additionthe pH adjusted to 2-3 by dropwise addition of concentrated HCl
3. extractionThe mixture was then extracted with ethyl acetate (3×75 ml)
4. washThe combined ethyl acetate extracts were washed with brine (1×100 ml)
5. dry with materialdried (magnesium sulfate)
6. filtrationfiltered
7. customThe solvent was evaporated in vacuo