The 2‐amino‐4′‐flouro‐benzophenone (1) that was reacted with chloroacetylchloride to afford 2‐chloro‐N‐(2‐(4′‐fluorobenzoyl) phenyl)acetamide (2) was subsequently converted to 1,4‐benzodiazepines (3) by the modification of the known hexamethylenetetramine based cyclization reaction developed by Blazevic and Kajfez. Thus, obtained product (3) was reacted with a variety of alkyl halide using KOH in DMF to give 1‐substituted‐5‐(4‐fluorophenyl)‐1H‐benzo[e][1,4]diazepin‐2(3H)‐one (4a, 4b). To achieve 1, 3‐disubstituted 1, 4‐benzodiazepines (5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i, 5j, 5k, 5l, 5m, 5n, 5o, 5p, 5q, 5r, 5s, 5t), 1‐substituted‐5‐(4‐fluorophenyl)‐1H‐benzo[e][1,4]diazepin‐2(3H)‐one (4a, 4b) was treated with various aromatic aldehydes in the presence of KOH in toluene.