Ethyl cyanoacetate → Ethyl 2-ethoxyethylidene-cyanoacetate
Reaktionsgleichung
[C:1]([CH2:3][C:4]([O:6][CH2:7][CH3:8])=[O:5])#[N:2].[C:9](OCC)(OCC)([O:11][CH2:12][CH3:13])[CH3:10]>CC(O)=O>[CH2:9]([O:11][CH2:12][CH:13]=[C:3]([C:1]#[N:2])[C:4]([O:6][CH2:7][CH3:8])=[O:5])[CH3:10]Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Reaktionsbedingungen
- Temperatur
- 135 °C
Versuchsvorschrift
To a stirred solution of Ethyl cyanoacetate (46.8 g, 414 mMol) and Triethyl orthoacetate (84.4 g, 520 mMol), in a 250 mL round bottom flask fitted with a short path distillation head, was added HOAc (1.2 mL, 21 mMol). The reaction was slowly heated to 135° C. and maintained at that temperature to distill off the ethyl alcohol that was produced. (Distillation started at ˜106° C.) At 15 min. intervals HOAc (1.2 mL, 21 mMol) was added to the reaction for an additional three times. The reaction was then slowly heated to 150° C. then cooled back down to ˜80° C. The title product (62.64 g, 82%) was obtained by short path distillation under high vacuum (bp 128° C., HV) as a pale yellow crystalline solid. (Note; Cooling to the condenser was shut off to prevent plugging.): 1H NMR (400 MHz, CDCl3) δ 4.27 (q, 2H), 4.22 (q, 2H), 2.61 (s, 3H), 1.43 (t, 3H), 1.31 (t, 3H).