反应详情

To a solution of 11.1 g (42.3 mmol) of 4-chloromethyl-2-phenylbenzoic acid methyl ester, prepared as in Example 187A, in 150 mL of toluene was added 1.7 g (6.4 mmol) of 18-Crown-6, and 8.40 g (63.1 mmol) of 3-hydroxypyridine, potassium salt. The reaction was stirred at ambient temperature for 20 minutes, then heated to reflux under N2. After 3 hours, the mixture was poured into 100 mL of water. The layers were separated, then the aqueous layer was extracted with ethyl acetate (3×100 mL). The combined organic layers were back extracted with 2M aqueous NaOH (2×30 mL), brine (1×100 mL), dried over magnesium sulfate, filtered, and concentrated to an oil which slowly crystallized. The product was recrystallized from 50 mL of 2-propanol to give 6.78 g of a tan solid. The supernatant was concentrated and purified via silica gel chromatography (50:50 hexanes:ethyl acetate) to give another 2.18 g of product, for a total yield of 8.96 g (66%). 1H NMR (300 MHz, d6-DMSO) δ 3.60 (s, 3H), 5.33 (s, 2H), 7.28-7.54 (m, 8H), 7.57 (dd, J=1.5, 9.0 Hz, 1H), 7.78 (d, J=9 Hz, 1H), 8.18 (dd, J=1.0, 5.5 Hz, 1H), 8.38 (d, J=3.0 Hz, 1H).

1. temperatureheated
2. temperatureto reflux under N2
3. waitAfter 3 hours
4. customThe layers were separated
5. extractionthe aqueous layer was extracted with ethyl acetate (3×100 mL)
6. extractionThe combined organic layers were back extracted with 2M aqueous NaOH (2×30 mL), brine (1×100 mL)
7. dry with materialdried over magnesium sulfate
8. filtrationfiltered
9. concentrationconcentrated to an oil which
10. customslowly crystallized
11. customThe product was recrystallized from 50 mL of 2-propanol