Synthesis of 4,5‐dihydro‐4‐methyl‐1‐phenyl‐1,4,5‐benzotriazocine‐2,3,6(1H) triones

Abstract

AbstractThe title compounds, 7a and its 9‐chloro analog 7b, were prepared in three steps from methyl N‐phenylanthranilates. Thus, methyl N‐phenylanthranilate (3a) was treated with oxalyl chloride to yield 2‐[(2‐chloro‐1, 2‐dioxoethyl) phenylamino]benzoic acid methyl ester (4a). Treatment of 4a with methylhydrazine gave 2‐([2‐(1‐methylhydrazino)‐1,2‐dioxoethyl]phenylamino) benzoic acid methyl ester (6a), which was cyclized with sodium hydride in dimethylformamide to produce 7a. Alkylation of 7a and 7b with iodomethane afforded the respective 5‐methyl derivatives 8a and 8b. A survey of the known literature benzotriazocines is presented.