Hydrochloric Acid → Ethyl 2-cyano-2-(hydroxyimino)acetate

Temperature

40 °C

A solution of sodium nitrite (57.30 g, 830.60 mmol) in water (710.00 ml) was treated with ethyl cyanoacetate (100.00 g, 884.00 mmol). 85% Orthophosphoric acid (36.60 ml, 540.00 mmol) was added dropwise over 45 min, while keeping the temperature of the reaction mixture below 35° C. with the aid of an ice bath. At the end of the addition, the mixture was warmed to 40° C. and stirred for 1 hour. The reaction was quenched at 45° C. with fuming HCl (73.90 ml, 880.00 mmol), and the mixture was then left to cool to room temperature and at 0° C. overnight to complete precipitation. The solid was filtered, the filtrate washed with water and dried under high vacuum overnight to yield 70 g of cyano-hydroxyimino-acetic acid ethyl ester as white crystals. A second batch was obtained by extracting the mother liquor with ether (44.00 g, total yield 91%).

1. customthe temperature of the reaction mixture below 35° C.
2. additionAt the end of the addition
3. waitthe mixture was then left
4. temperatureto cool to room temperature and at 0° C. overnight
5. customprecipitation
6. filtrationThe solid was filtered
7. washthe filtrate washed with water
8. customdried under high vacuum overnight

ORD record

ord-40e6f8f5f349420b9555f1dd76a6a61b

Source dataset

uspto-grants-2010_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07678815B2