Process for synthesizing oxidized lactam compounds
View Patent ↗The invention provides a method for the synthesis of dehydrogenated lactam drugs of Formula I:
1. A method for preparing a compound of Formula VI, comprising the step of reacting a compound of Formula VIA with a compound of Formula II in the presence of an acid:
wherein each R A , R B , R C , and R D is independently selected from hydrogen, halogen, —CN, NH 2 , NR 100 R 101 , SR 100 , OR 100 , aliphatic, substituted aliphatic, aryl and substituted aryl; wherein R 100 and R 101 , are independently selected from hydrogen, halogen, aliphatic, substituted aliphatic, aryl or substituted aryl.
2. The method according to claim 1 , wherein said compound of Formula II is selected from 3,4-dichloro-5,6-dicyano-1,4-benzoquinone, 3,4,5,6-tetrachloro-1,2-benzquinone, ortho-benzoquinone and para-benzoquinone.
3. The method according to claim 1 , wherein said acid is selected from trifluroacetic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, chlorosulfonic acid, dichloroacetic acid, trichloroacetic acid, acetic acid, propionic acid, sulfuric acid, phosphoric acid, nitric acid, camphorsulfonic acid, hydrochloric acid, oxalic acid, formic acid, propanoic acid, butanoic acid, pentanoic acid, benzoic acid, pyruvic acid, malonic acid, succinic acid, glutaric acid, fumaric acid, citric acid, ascorbic acid, tartaric acid, maleic acid, and hydrobromic acid, and mixtures thereof.
4. The method according to claim 1 , wherein the reaction is conducted in a solvent selected from tetrahydrofuran, tert-butylmethylether, dimethoxy-ethane, dioxane, benzene, toluene, xylene, dimethylformamide, acetone, acetonitrile, chloroform, dichloromethane, 1,2-dichloroethane, ethyl acetate, n-propyl acetate, isopropyl acetate, methyl-t-butyl ether, methyl butyl ketone and combinations thereof.