Process for the preparation of benzo [d] isoxazol-3-yl-methanesulfonic acid and the intermediates thereof
AssigneeDipharma S.p.A.
InventorsGabriele Razzetti, Simone Mantegazza, Graziano Castaldi, Pietro Allegrini, Vittorio Lucchini, Alberto Bologna
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Abstract
A process for the preparation of benzo[d]isoxazol-3-yl-methanesulfonic acid of formula (I), or a salt thereof, and the intermediates thereof, useful as an intermediate in the preparation of zonisamide.
Claims11
A process for the preparation of benzo[d]isoxazol-3-yl-methanesulfonic acid of formula (I)
- or a salt thereof, comprising the reaction of an oxime of formula (III)
- with a basic agent.
A benzo[d]isoxazol-3-yl-methanesulfonic acid salt, which is the lithium salt or the salt with an organic base.
A crystalline compound of formula (III) or an isomer thereof
A process for the preparation of zonisamide, comprising the treatment of a benzo[d]isoxazol-3-yl-methanesulfonic acid of formula (I)
- or a salt thereof with a halogenating agent to obtain a benzo[d]isoxazol-3-yl-methanesulfonyl halide of formula (IV)
- wherein X is halogen, and the treatment of compound (IV) with ammonia;
- wherein the benzo[d]isoxazol-3-yl-methanesulfonic acid of formula (I), or a salt thereof, is obtained by a process comprising treating an oxime of formula (III)
- with a basic agent.
A process for preparing a ketosultone of formula (II), i.e. 2,2-dioxo-2,3-dihydro-2lambda*6*-benzo[e][1,2]oxathiin-4-one, comprising reacting a compound of formula (V)
- with a basic agent.
Dependencies are inferred from the claim text.