Yield:254880-25-6 4.5 g

Reaction Conditions:

Stage #1: 1-amino-2-chloro-4-cyanobenzenewith hydrogenchloride;NaNO₂ in lithium hydroxide monohydrate at -5; for 0.5 h;
Stage #2: with dichloro-λ²-stannane dihydrate in lithium hydroxide monohydrate; for 4 h;Cooling with ice;

Steps:

1.1 Step 1: Preparation of compound 2-chloro-4-cyanophenylhydrazine:

Under the conditions of ice salt bath, 100 ml of concentrated hydrochloric acid was added to the 500 ml three-mouth flask with built-in thermometer, 5 g of 2-chloro-4 cyanoaniline was added, when the temperature dropped to -5 degrees Celsius, 2.49 g of sodium nitrite was dissolved in 10 ml of water and slowly added to the system, after stirring for 30 minutes, 18.5 g of stann chloride dihydrate was dissolved in concentrated hydrochloric acid with a constant pressure drip device slowly added to the system, and continued to stir for 4 hours under ice salt bath conditions. With 6 moles / liter of aqueous sodium hydroxide solution, the pH of the system was adjusted to about 13, a large amount of solids were precipitated, and 4.5 grams of yellow solids were obtained, that is, 2-chloro-4-cyanophenylhydrazine.

References:

CN114621144,2022,A Location in patent:Paragraph 0055-0058