反应详情

A solution of allyl alcohol (16 g, 276 mmol) and 2-chloropyridine (32 g, 282 mmol) in methylene chloride (100 ml) was added over 30 min to a stirred solution of trifluoromethanesulfonic anhydride (78 g, 277 mmol) in methylene chloride (200 ml) at 0° C. The mixture was stirred in an ice bath for 3 h, and then filtered cold to remove the salt byproduct. The brown allyl triflate solution was stored in a freezer for use in the following reaction. A solution of 2,2-dinitropropanol (24 g, 160 mmol) in methylene chloride (100 ml) was added, with ice bath cooling, over 15 min to a stirred mixture of one-half of the allyl triflate solution and anhydrous sodium sulfate (50 g). The ice bath was removed. After the mixture was stirred at room temperature for 17 h, sodium sulfate (40 g) and half of the remaining allyl triflate solution were added. After another 8 his of stirring at ambient temperature, another 40 g portion of sodium sulfate and the remaining allyl triflate solution were added, and stirring was continued for 17 h. The mixture was filtered. The solution was washed with saturated sodium bicarbonate solution and with water. The solution was dried over magnesium sulfate and solvent was removed under vacuum. The brown liquid residue was distilled to give 25.7 g of allyl 2,2-dinitropropyl ether, by 50° C./0.1 mm Hg, 84% yield based on dinitropropanol: HNMR (acetone-d6): 2.20 (s, 3H), 4.15 (t of d, 2H), 4.37 (s, 2H), 5.22 (AB quartet, of d, 1H), 5.30 (AB quartet of d, 1H), 5.90 (m, 1H) ppm; IR (neat): 2890 (m), 1573 (br, vs), 1469 (m), 1445 (m), 1424 (m), 1401 (m), 1383 (m), 1349 (m), 1328 (s), 1273 (w), 1230 (w), 1195 (m), 1099 (br, s), 989 (s), 939 (s), 869 (m), 848 (m), 776 (w), 736 (w) cm−1.

1. filtrationfiltered cold
2. customto remove the salt byproduct
3. customThe brown allyl triflate solution was stored in a freezer for use in the following reaction
4. customThe ice bath was removed
5. stirringAfter the mixture was stirred at room temperature for 17 h
6. additionsodium sulfate (40 g) and half of the remaining allyl triflate solution were added
7. stirringAfter another 8 his of stirring at ambient temperature
8. additionanother 40 g portion of sodium sulfate and the remaining allyl triflate solution were added
9. stirringstirring
10. waitwas continued for 17 h
11. filtrationThe mixture was filtered
12. washThe solution was washed with saturated sodium bicarbonate solution and with water
13. dry with materialThe solution was dried over magnesium sulfate and solvent
14. customwas removed under vacuum
15. distillationThe brown liquid residue was distilled