Derivatives of 1,2-benzisoxazole-3-methane sulfonic acid as novel intermediates for the synthesis of zonisamide

A process of preparing 1,2-benzisoxazole-3-methanesulfonic acid ammonium salt, the process comprising;

• providing a first mixture containing 3-bromomethyl-1,2-benzisoxazole and a first alcohol;
• providing a second mixture containing ammonium sulfite and water;
• reacting said first mixture and said second mixture to thereby obtain a reaction mixture containing the 1,2-benzisoxazole-3-methanesulfonic acid ammonium salt;
• and isolating the 1,2-benzisoxazole-3-methanesulfonic acid ammonium salt from said reaction mixture, thereby obtaining the 1,2-benzisoxazole-3-methanesulfonic acid ammonium salt.