Synthesis, physicochemical and biological evaluation of 2-amino-5-chlorobenzophenone derivatives as potent skeletal muscle relaxants

A series of novel 2-amino-5-chlorobenzophenone derivatives (3a–3g) were prepared by the reaction of 2-(chloroacetamido)-5-chlorobenzophenone and different aniline derivatives by both conventional and microwave methods and structures were confirmed on the basis of their TLC, IR, 1H NMR and CHN elemental studies. Out of the two methods, microwave methods was found to give better yield. All the synthesized compounds were subjected to physicochemical parameters determination for BBB penetration through online software. The log P values of most of our test compounds indicate that test compounds have the potential to be CNS active. The experimentally determined and calculated values of log P are very much similar to values of log P calculated by the online software chemsilico and are in the range required for good CNS activity. The values of other physicochemical parameters like molecular weight, nON value, nOHNH value, n-violations and the number of rotatable bonds of all the test compounds also lie between the ranges that are required for good BBB penetration. The compounds were screened for the skeletal muscle relaxant activity and from the investigation, it is quite apparent that all the 2-amino-5-chlorobenzophenone derivatives (3a–3g) possess significant differences between control group and treated group, P < 0.001. Among these 2-amino-5-chlorobenzophenone derivatives, the compound bearing o-toluidine as a substituent (3e) possesses the highest skeletal muscle relaxant activity.