反应详情

A mixture of resorcinol (2.2 g, 20 mmol), 3-pyridin-2-yl-propionic acid sulphuric acid salt (5 g, 20 mmol) and 50 ml boron trifluoride diethyl etherate (BF3.Et2O) was stirred at 90 C for 5 hours under N2 (monitored by TLC). The reaction mixture was poured into 10% aqueous NaOAc solution and allowed to stand for 30 min and the solution was neutralized to pH=7 by 1M HCl and was extracted with EtOAc (3×50 ml). The combined EtOAc layer was washed with water, brine and dried over Na2SO4. The residue obtained after evaporation of the solvent was chromatographed over silica gel column using hexane-EtOAc mixture (1:1) as eluent to give mixture of products, which was then recrystallized in hot MTBE/Hex to afford final product (24%) with >97% purity.

1. waitto stand for 30 min
2. extractionwas extracted with EtOAc (3×50 ml)
3. washThe combined EtOAc layer was washed with water, brine
4. dry with materialdried over Na2SO4
5. customThe residue obtained
6. customafter evaporation of the solvent
7. customwas chromatographed over silica gel column
8. customto give
9. additionmixture of products, which
10. customwas then recrystallized in hot MTBE/Hex