反应详情

温度

50 °C

To a solution of the vinylogous amide 2 (1.135 g, 6.06 mmol) and dibutylaniline (1.43 g) in dry THF (6 ml) at −20° C. was added a solution of phosphorus oxychloride (1.08 g, 1.17 eq.) and dibutylaniline (1.03 g, 1.98 eq. for the sum) in THF (3.6 ml) dropwise at such a rate as to keep the mixture between −10° C. and −20° C. Following the addition, the mixture was stirred at room temperature for 2 hours and at 50° C. for 35 minutes. To the reaction mixture (a dark blue-green oil) was added petroleum ether (25 ml) and the mixture was triturated; the ether was separated and discarded. Methanol (4 ml) was then added and the mixture was neutralized with 2N NaOH. Silicagel was then added, the suspension was diluted with ethyl acetate and methanol and dried to a solid on the rotovap. The crude product was purified by MPLC using hexanes-ethyl acetate 5-30% gradient to give the desired aldehyde as an intense yellow oil (225 mg, 13%). MS (EI): 285 (M+, 45%); 242 (100%); 200 (85%); 128 (30%); 118 (40%). H-NMR (CDCl3): 0.95 (t, J=12 Hz, 6H); 1.35 (m, 4H); 1.45 (m, 4H); 3.8 (t, J=9 Hz, 4H); 6.4, (d, J=17 Hz, 1 H); 6.5-6.8 (m, 3H); 7.1 (d, J=15 Hz,1 H); 7.5 (d, J=17 Hz,1 H); 7.8 (d, J=11 Hzm 2H); 9.8 (s,1 H).

1. customthe mixture between −10° C. and −20° C
2. additionthe addition
3. customthe mixture was triturated
4. customthe ether was separated
5. additionMethanol (4 ml) was then added
6. additionSilicagel was then added
7. additionthe suspension was diluted with ethyl acetate and methanol
8. customdried to a solid on the rotovap
9. customThe crude product was purified by MPLC