反应详情

Ketone starting material for A-077 was prepared from picolinic acid and 4-methoxybenzaldehyde. To a solution of 50 g. (0.37 moles) of 4-methoxybenzaldehyde and 50 ml. p-cymene (heated to dissolve) in a 3-neck flask with reflux condenser and refluxed until boiling, 10 g. (0.08 moles) picolinic acid was added dropwise and then refluxed for three hours. The solution changed in color from reddish to brown at the end. The solution was cooled and extracted in a separatory funnel with 2 N HCl (twice with 50 ml.). The above acid layer was washed twice with 100 ml. diethyl ether. The ether layer was discarded. The acid layer was basified with ice cold concentrated ammonium hydroxide at 0° C. The basic layer was extracted with diethyl ether (3×100 ml.) until clear. The ether washings were collected and dried over anhydrous sodium sulfate. The filtered ethereal solutions were evaporated (under roto-vacuum) at room temperature until an oil formed. The oil was dissolved in minimal ethanol to solubilize, and hot water dropwise was added until turbidity was produced and then disappeared on further heating. On cooling, a cloudy layer formed an oil which was removed by hand aspiration rapidly because it precipitated quickly. The 4-methoxybenzyl(2-pyridyl) carbinol oil was recrystallized from ethanol-water (80:20) as a white powder, 65% yield, mp 110°-112° C. Calc. for C14H13NO2 : C, 74.01; H, 5.73; N, 6.16. Found: C, 74.09; H, 6.01; N, 6.04.

1. temperaturerefluxed
2. temperaturerefluxed for three hours
3. temperatureThe solution was cooled
4. extractionextracted in a separatory funnel with 2 N HCl (twice with 50 ml
5. washThe above acid layer was washed twice with 100 ml
6. customwas basified with ice cold concentrated ammonium hydroxide at 0° C
7. extractionThe basic layer was extracted with diethyl ether (3×100 ml.) until clear
8. customThe ether washings were collected
9. dry with materialdried over anhydrous sodium sulfate
10. customThe filtered ethereal solutions were evaporated (under roto-vacuum) at room temperature until an oil
11. customformed
12. customwas produced
13. temperatureOn cooling
14. customa cloudy layer formed an oil which
15. customwas removed by hand aspiration rapidly because it
16. customprecipitated quickly
17. customThe 4-methoxybenzyl(2-pyridyl) carbinol oil was recrystallized from ethanol-water (80:20) as a white powder, 65% yield, mp 110°-112° C