4-hydrazinylbenzonitrile synthesis

Yield: 65%

Reaction Conditions:

Stage #1:4-Aminobenzonitrile with hydrogenchloride;sodium nitrite in water at 0;
Stage #2: with tin(II) chloride dihdyrate in water at 0; for 0.25 h;

Steps:

3.1 Step 1 - Synthesis of 4-Hydrazinylbenzonitrile
A cold solution of sodium nitrite (2.16 mmol, 149 mg) in water (8.1 mL) was added dropwise to a cold solution of 4-aminobenzonitrile (2 mmol, 236 mg) in concentrated hydrochloric acid (2.6 mL) at 0 °C maintaining the temperature. Cold diazonium salt solution was added dropwise to a slurry of tin (II) chloride dihydrate (10 mmol, 2.26 g) maintaining the temperature at 0 °C. Upon further stirring for 15 minutes, filtration was performed to collect the white precipitate formed. The precipitate was thoroughly washed with diethyl ether to yield pure 4- hydrazinylbenzonitrile as a beige colour solid (174 mg, 65%), m.p. 158-160 °C. d_H (400 MHz,DMSO) 10.21 (br, 2H, NH₂), 8.99 (br, 1 H, NH), 7.71 (d, J = 9.2 Hz, 2H, ArH), 7.00 (d, J = 9.2 Hz, 2H, ArH). 5_C (400 MHz, DMSO) 150.1 , 133.8, 119.9, 114.2, 102.3.

References:

LA TROBE UNIVERSITY;PERUGINI, Matthew, Anthony;ABBOTT, Belinda, Maree;SOARES DA COSTA, Tatiana, Pereira WO2019/241850, 2019, A1 Location in patent:Paragraph 0204-0205