The present invention is related to a process for preparing anthranilamides of formula I, in which R(1) to R(7) have the meanings indicated herein, a process for their preparation, their use as medicaments, and pharmaceutical preparations containing them. The compounds act on the Kv1.5 potassium channel and inhibit a potassium current which is referred to as the ultra-rapidly activating delayed rectifier in the atrium of the human heart. The compounds are therefore suitable for use as novel antiarrhythmic agents for the treatment and prophylaxis of atrial arrhythmias (e.g., atrial fibrillation (AF) or atrial flutter).