Acetic Acid → (1-Ethoxyethylidene)malononitrile

Triethyl orthoacetate (1.6 L, 9 mol), malononitrile (500 g, 7.57 mol) and glacial acetic acid (25 ml) were placed in a 5 l RB flask equipped with a stirrer, thermometer and a Vigreux column (20×1 in.) on top of which a distillation condenser was placed. The reaction mixture was heated and ethyl alcohol began to distil when the temperature of the reaction mixture was about 85-90° C. After about 3 h., the temperature of the reaction mixture reached 140° C. Then the reaction was concentrated in a rotary evaporator to remove the low-boiling materials and the residue was stirred with isopropyl alcohol (1 l) and cooled in an ice bath. The crystallized product was filtered off washed with isopropyl alcohol (200 ml), hexanes (600 ml) and dried at 50° C. in a vacuum oven overnight to yield 2-(1-ethoxy-ethylidene)-malononitrile (974 g, 94%) as a golden yellow solid [mp 92.° C. (lit.90-92° C., MCCall. M. A. J. Org. Chem. 1962, 27, 2433-2439.)].

1. customequipped with a stirrer
2. temperatureThe reaction mixture was heated
3. customto distil when the temperature of the reaction mixture
4. customwas about 85-90° C
5. customreached 140° C
6. concentrationThen the reaction was concentrated in a rotary evaporator
7. customto remove the low-boiling materials
8. temperaturecooled in an ice bath
9. filtrationThe crystallized product was filtered off
10. washwashed with isopropyl alcohol (200 ml), hexanes (600 ml)
11. customdried at 50° C. in a vacuum oven overnight

ORD record

ord-9695923ea33e43519c2b89140c8818ca

Source dataset

uspto-grants-2009_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07498333B2