5-//4-/(4',6'-dimethyl-2-pyrimidinyl)sulfamoyl/phenyl/azo /acetylsalicylic acid(DISALAZINE) This inventin relates to 5-//4-/(4',6'-dimethyl-2-pyrimidinyl) sulfamoyl/phenyl/azo /acetylsalicylic acid (DISALAZINE) with the production via diazonium salt of sulfadimidine reacted with salicylic acid and then is acetylated. Claimed substance has anti-arthritic and immunomodulating properties.