Preparation of tetrahydroimidazo[2,1-a]isoquinolines and their use as inhibitors of gastric acid secretion.

A series of novel tetrahydroimidazo[2,1-a]isoquinolines was prepared based on a hetero Diels-Alder reaction between an enamine and 1,2,4-triazine as key step. A structure-activity relationship was established focussing on the influence of the substitution pattern in position 3 and 6 of the heterocycle on antisecretory activity, lipophilicity, and pK(a) value. Potent inhibitors of the gastric acid pump were identified.