The present invention provides calcium sensing receptor modulators (CaSR). In particular, the compounds described herein are useful for treating, managing, and/or lessening the severity of diseases, disorders, syndromes and/or conditions associated with the modulation of calcium sensing receptors (CaSR). The invention also provides herein the pharmaceutical compositions thereof, and methods for treating, managing, and/or lessening the severity of diseases, disorders, syndromes and/or conditions associated with the modulation of CaSR. The invention also relates to process for the preparation of the compounds of the invention.