Part 6: Synthesis of Spiro 1,5‐Benzodiazepine Attached with Different Heterocyclic Moeities

Abstract

3‐Oxime‐4‐phenyl‐1(H)(l,5)benzodiazepin‐2‐one 2 was prepared and treated with malononitrile, arylidenenitriles, and bidentates to give the corresponding spiro‐3,3′‐isoxazolo‐, thiadiazino‐, and triazino‐1,5‐benzodiazepines 3–7. 3‐Bromo‐3‐cyano‐4‐phenyl‐l(H)(l,5)benzodiazepin‐2‐one 9a and 3‐bromo‐3‐cyano‐4‐(4′‐bromophenyl)‐1(H)(l,5)benzodiazepin‐2‐one 9b were synthesized via the bromination of 3‐cyano‐4‐phenyl‐1(H)(l,5)benzodiazepin‐2‐one 8. Compounds 9a,b were reacted with bidentates or cyclopentanone to afford spiro piprazine, quinoxaline, thiazine, thiadiazine, imidazole, and cyclopentafuran derivatives 10–16. Treatment of compound 1 with p‐tolyldiazonium chloride gave 3‐(p‐tolylazo)‐4‐phenyl‐1(H)(1,5)‐benzodiazepin‐2‐one 17, which in turn treated with nitriles, cyclopentanone, and S,S‐acetal derivative to give the corresponding spiro pyrazole, cyclopentapyrazole, and thiadiazole derivatives 18–21.

Keywords:

• 3‐bromo‐3‐cyano‐4‐phenyl‐l(H)(1,5)benzodiazepin‐2‐one
• 3‐oxime‐4‐phenyl‐1(H)(1,5)benzodiazepin‐2‐one
• PTC
• 3‐(p‐tolylazo)‐4‐phenyl‐1(H)(1,5)benzodiazepin‐2‐one