The invention is concerned with novel imidazopyrimidine derivatives of formula (I)wherein R1, R2and R8are as defined in the description and in the claims, as well as physiologically acceptable salts and esters thereof. These compounds inhibit PDE10A and can be used as medicaments.本發明係關於新穎之式(I)咪唑并嘧啶衍生物,其中R1、R2及R8如說明書及申請專利範圍中所定義,以及其生理學上可接受之鹽及酯。此等化合物抑制PDE10A且可用作藥物。