Action of Hydrogen Cyanide on Quinones

Reaction L. (c) Action of Hydrogen Cyanide on Quinones. (B., 33, 675 D.R.P., 117005.)—Hydrogen cyanide reacts easily with quinones to give dicyano-dihydroxy derivatives of the parent hydrocarbons. A molecule of the quinone is simultaneously reduced. 

Reaction LI. (a) Action of Acids on the non-para substituted Hydrazo Compounds. (A., 270, 330 287, 97 B 26, 681, 688, 99.)—When hydrazobenzene is treated with mineral acids, an intermolecular rearrangement to benzidine (pj-pg-diaminodiphenyl) takes place. 

This reaction can be extended to almost all non -para substituted hydrazo compounds if one or both para-positions are substituted, either ortAo-benzidine or diphenylamine derivatives known as ortho- or para-semidines are formed. 

Benzidine and its homologues are very important intermediates in the dye industry. 

---