Novel compounds as histamine h3 receptor ligands

The disclosure relates to cyclobutyl-piperidin-acetamide derivative compounds of formula (I), and their pharmaceutically acceptable salts and compositions containing them, wherein the variables are as defined in the specification. The disclosure also relates to a process for the preparation of above said compounds, and their pharmaceutically acceptable salts. The compounds of formula (I) are useful in the treatment of various disorders that are related to Histamine H receptors, wherein the disorders include cognitive disorders, dementia, attention deficit hyperactivity disorder, schizophrenia, epilepsy, sleep disorders, sleep apnea, obesity, eating disorders and pain.