The Nitrile Carboxamide Rearrangement
By reaction of cyclohexanone‐2‐carboxamide (4) with cyan amide 1‐cyano‐cyclohex‐1‐en‐2‐yl‐urea (6) is formed via nitrile carboxamide rearrangement. Whilst compound 6 with 1,2‐diaminobenzene hydrochloride forms 11‐amino‐1 H‐2,3,4,5‐tetrahydrodibenzo[b,e][1,4]diazepin hydrochloride (8 and 8a), compound 6 and 1,2‐diaminobenzene form hexahydro‐benzimidazo[1,2‐c]‐quinazolin‐6‐one (12). Compound 8 with sodium hydroxide yields 11‐amino‐1 H‐2,3,4,11a‐tetrahydrodibenzo[b,e]‐[1,4]diazepin (9). Compound 6 reacts with cyclohexylamine to form N‐(1‐cyanocyclohex‐1‐en‐2‐yl)‐N′‐cyclohexyl urea (10). Compound 10 with 1,4‐ or 1,2‐diaminobenzene hydrochloride yields compound 7 and 8. In alkaline solution 10 cyclises to 4‐amino‐3‐cyclohexyl‐2,3,5,6,7,8‐hexahydroquinazolin‐2‐one (11). Compound 4 and malonitrile form either 3‐amino‐4‐cyano‐1,2,5,6,7,8‐hexahydro‐isoquinol‐1‐one (13) or 1‐amino‐4‐cyano‐2,3,5,6,7,8‐hexahydro‐isoquinol‐3‐one (14). Compound 13 and alkaline formaldehyde react to cyanooctahydroisoquinoline‐[2,3‐c] [1,3,5]oxdiazin‐6‐one (17). 2‐Cyanoethyl‐cyclohexan‐one‐2‐carboxamide (22), prepared by Michael‐reaction from 4 and acrylonitrile, forms via nitrile carboxamide rearrangement 10‐cyano‐1,2,3,4,5,6,7,10‐octahydroquinolin‐2‐one (24) and 2‐(1′‐cyano‐cyclohexyl‐2′‐one)‐propionic acid (25). Nucleophilic attack of the NH~2~‐group at the cyanogroup of compound 22 forms 5‐(spirocyclohexan‐2′‐one)‐hexahydropyridin‐2,6‐dione (27).