反应详情

N,N-Dimethylhydrazine (10.90 mL, 0.14 mol) was added dropwise over 15 min to (E)-4-methoxy-2-butenal (13.06 g, 0.13 mol) while cooling the reaction with an ice bath. The bath was then removed and the mixture stirred for 1.5 h at ambient temperature. Calcium chloride (20 g) was added to the reaction, let set for 15 min, and the product decanted. Distillation (bp 102°-110° C., 25 mm Hg) of the oil through a 10 cm Vigreaux column provided pure (E)-4-methoxy-2-butenal N,N-dimethylhydrazone (17) (14.45 g, 78%): IR (neat) 2850, 2820, 1560, 1465, 1445, 1375, 1270, 1120, 1030, 970 cm-1 ; 1H NMR (CDCl3) δ 2.80 (s, 6H), 3.26 (s, 3H), 3.93 (dd, 2H, J=6.2, 1.2 Hz), 5.74 (dt, 1H, J=15.8, 6.2 Hz), 6.31 (ddt, 1H, J=15.8, 8.9, 1.2 Hz), 6.92 (d, 1H, J=8.9 Hz); Anal. calcd for C7H14N2O: C 59.05, H 10.07, N 19.52; found C 59.13, H 9.92, N 19.70.

1. temperaturewhile cooling
2. customthe reaction with an ice bath
3. customThe bath was then removed
4. additionCalcium chloride (20 g) was added to the reaction
5. waitlet set for 15 min
6. customthe product decanted
7. distillationDistillation (bp 102°-110° C., 25 mm Hg) of the oil through a 10 cm Vigreaux column