反应详情

A solution of 20 g (0.826 mole) of 2-amino-5-nitro benzophenone (cp. Ullmann, Ber. 31, 1965) in 400 ml of glacial acetic acid and 20 ml of conc. hydrochloric acid is diazotised at 20°-25°, with stirring, with 16.5 ml (0.826 mole) of aqueous sodium nitrite solution. To the obtained diazonium salt solution there are added 400 g of ice, and rapidly dropwise a solution of 174 g (0.69 mole) of (2-chloroacetamido)-malonic acid diethyl ester [cp. Ajay Kumar Bose, J. Indian Chem. Soc. 31, 108-110 (1954)] in 400 ml of acetone. A solution of 114 g (0.826 mole) of potassium carbonate in 250 ml of water is subsequently added dropwise at 5°-10° within 20 minutes; stirring is continued for an hour, and benzene and saturated sodium chloride solution added. The benzene solution is separated, washed repeatedly with a mixture of saturated sodium chloride solution and 5% sodium bicarbonate solution until free from acid, dried over sodium sulphate and concentrated by evaporation, whereby crude (2-chloroacetamido) (2-benzoyl-4-nitrophenylazo)-malonic acid diethyl ester is obtained.

1. customis diazotised at 20°-25°
2. waitis continued for an hour
3. customThe benzene solution is separated
4. washwashed repeatedly with a mixture of saturated sodium chloride solution and 5% sodium bicarbonate solution until free from acid
5. dry with materialdried over sodium sulphate
6. concentrationconcentrated by evaporation