Process for preparing a polymorph or rosiglitazone maleate

A process for preparing the rosiglitazone maleate polymorph, Compound 1 substantially free of other polymorphs, which comprises crystallizing rosiglitazone maleate in a solvent with a dielectric constant of less than 21 or a mixture of solvents wherein at least one solvent has a dielectric constant of less than 21.

A process for preparing the rosiglitazone maleate polymorph (Compound 1) essentially free of any other polymorphic forms, which comprises crystallizing rosiglitazone maleate in a solvent or mixture of solvents with a dielectric constant such that it provides Compound 1 essentially free of any other polymorphic forms.

A process for preparing the Compound 1 essentially free of any other polymorphic forms of rosiglitazone maleate which comprises crystallizing rosiglitazone maleate from a solvent or mixture of solvents wherein the solvent or at least one of the solvents has a dielectric constant of less than 14.

(canceled)

A process for preparing the Compound 1 essentially free of any other polymorphic forms of rosiglitazone maleate which comprises crystallizing rosiglitazone maleate from a solvent or mixture of solvents selected from anisole, isopropyl acetate, ethyl acetate, dichloroethane, dimethyl carbonate, methyl isobutyl ketone, tetrahydrofuran or a mixture ethyl acetate and denatured ethanol (IMS).