The present invention relates to compounds of formula I,wherein A, R1 to R7 are defined in the description, and to pharmaceutically acceptable salts thereof. The present invention also relates to the manufacture of such compounds or their pharmaceutically acceptable salts, pharmaceutical compositions containing them and their use as medicaments for the treatment and/or prophylaxis of diseases which can be treated with HDL-cholesterol raising agents, such as dyslipidemia, atherosclerosis and cardiovascular diseases.