The present invention relates to compounds of the formula I in which A1, A2, R2 and R3 have the meanings indicated in the claims, which are valuable pharmaceutical active compounds for the therapy and prophylaxis of diseases, for example of cardiovascular disorders such as high blood pressure, angina pectoris, cardiac insufficiency, thromboses or atherosclerosis. The compounds of the formula I have the ability to modulate the endogenous production of cyclic guanosine monophosphate (cGMP) and are generally suitable for the therapy and prophylaxis of disease states which are associated with a disturbed cGMP balance. The invention relates to the use of compounds of the formula I for the therapy and prophylaxis of the designated disease states and for the production of pharmaceuticals therefor, novel compounds of the formula I, pharmaceutical preparations comprising them and processes for their preparation.