The present invention relates to heterocyciic compounds of formula 1, in all their stereoisomeric and tautomeric forms; and their pharmaceutically acceptable salts, solvates, polymorphs, prodrugs, carboxylic acid isosteres and N-oxides. The invention also relates to processes for the manufacture of the heterocyclic compounds and to pharmaceutical compositions containing them. The said compounds and their pharmaceutical compositions are useful in the prevention and treatment of diseases or disorders mediated by diacylglycerol acyltransferase (DGAT), particularly DGAT1. The present invention further provides a method of treatment of such diseases or disorders by administering a therapeutically effective amount of said compounds or their pharmaceutical compositions, to a mammal in need thereof.本發明係關於一種分子式1的雜環化合物,以所有其立體異構物及互變異構形式;及其醫藥可接受鹽類、溶劑化物、多晶型物、前藥、羧酸同電子排列體及N-氧化物相關。本發明亦與雜環化合物的製備方法及包含雜環化合物的醫藥組成物相關,該化合物及其醫藥組成物有用於預防及治療由二醯基甘油醯基轉移酶(DGAT),特別是DGAT1所媒介的疾病或失調。本發明更提供一種藉由投藥醫療有效量的該化合物或其醫藥組成物予需要分子式1化合物的哺乳動物來治療此種疾病或失調的方法。