Screening And Solid-state Transformation Of Salts And Polymorphs Of 5-sulfosalicylic Acid And Isonicotinine

Screening and preparation of SSA-INA salts by using mechanical grinding and solvent evaporation method to study the crystals structure and the salts transformation between different crystal forms.1.Obtaining three polymorphs of sulfosalicylic acid?SSA?and isonicotinine?INA?salts:SSA and INA are mixed with ethanol or water at a molar ratio of 1:1 to obtain SSA₁·INA₁·H₂O polymorphic Form II and Form III,Form II is grounded by addition of ethanol solvent,and the Form III is obtained by grinding with water,and the crystals of Form II Form III are obtained by traditional solvent evaporation method,and unexpectedly obtained Form I.Water molecules are involved in all three polymorphs.We also study the stability of three polymorphs and the transformation of three phases under solid state conditions.The stability of the three polymorphs is Form I<Form II<Form III.2.To study the controlled synthesis and phase transition of different solvents and different proportions of SSA-INA salt.Dropping the methanol solvent and grinding the SSA-INA?1:1?in solid state can produce the SSA₂INA₂·H₂O·MeOH.The crystal is obtained by the solvent evaporation method in 4 mL methanol.When SSA and INA are ground at a ratio of 1:2 to obtain SSA₁·INA₂,crystals is obtained in ethanol solvent.Dissolving SSA and INA in 1:1 ratio in 2 ml methanol gets the crystal of SSA₁·INA₁·MeOH.The SSA₂·INA₂ crystal is accidentally obtained in ethanol solvent and cannot repeat.3.By adding an equimolar ratio of INA molecules to grind in crystals SSA₁·INA₁·MeOH,SSA₂·INA₂·H₂O·MeOH,SSA₁·INA₁·H₂O,they can all transform SSA₁·INA₂ salt,adding SSA·2H₂O to SSA₁INA₂ and dropping different solvents can achieve 1:1 different crystals transformation.