反应详情

Hydrogen chloride was introduced to a stirred mixture of 164 g (0.839 mole) of crude ethyl 2-cyano-5-(N,N-dimethylamino)-3-methyl-2,4-pentadienoate (5) in 500 mL ethanol at 20-45° C. The mixture was stirred at ambient temperature overnight, then heated to reflux for 8 hours. The ethanol was removed under reduced pressure and the residue distilled under high vacuum at 84-94° C., to give 47.7 g (30.4%) of a yellow oil, MH+ 200, NMR (CDCl3), ppm: 1.42 (t,3H); 2.36 (s,3H); 4.46 (q,2H); 7.12 (d,lH); 8.28 (d,1H).

1. temperatureheated
2. temperatureto reflux for 8 hours
3. customThe ethanol was removed under reduced pressure
4. distillationthe residue distilled under high vacuum at 84-94° C.