The present disclosure relates to substituted amides that are inhibitors of fatty acid amide hydrolase (FAAH), their stereoisomers, tautomers, prodrugs, polymorphs, solvates, pharmaceutically acceptable Salts, and pharmaceutical compositions containing them. These compounds are useful in the treatment, prevention, prevention, management or adjunctive treatment of all medical conditions associated with the inhibition of fatty acid amide hydrolase (FAAH), such as pain, including acute and postoperative pain, chronic pain, Cancer pain, pain from cancer chemotherapy, neuralgia, nociceptive pain, inflammatory pain, back pain, pain from various sources such as: diabetic neuropathy, neurotropism involving human immunodeficiency virus (HIV) type viral diseases, herpes zoster such as postherpetic neuralgia; polyneuropathy, neurotoxicity, mechanical nerve damage, carpal tunnel syndrome, immunological mechanisms such as multiple sclerosis; sleep disorders, anxiety and depression, inflammatory diseases, Weight and eating disorders, Parkinson's disease, addiction, cramps, high blood pressure, or other medical conditions. The present disclosure also relates to a preparation method of the amide compound. Formula 1). The disclosure also relates to processes for the preparation of such compounds, and to pharmaceutical compositions containing them.