Synthesis and X-ray Crystallographic Studies of Salts, Co-crystals, Solvates of some Amine containing Active Pharmaceutical Ingredients and In-situ Cryo Crystallographic Studies on some Organic Liquids

Abstract

Chapter I describes the general introductory note to describe the common terms like crystalline solids, properties, and their uses pharmaceutical industry. The definition of common terms like Salts, Co-crystal, solvates were introduced along with factor affecting crystallization specially on pharmaceutical Co-crystals. The general discussion on hydrogen bonds, halogen bonds and chalcogen bonds and study of weak interaction through in-situ Cryo-crystallization were introduced. Chapter II emphasizes the importance of intermolecular interactions in pharmaceutical co-crystal and in formation of unusual base pairs are investigated. Efforts have been made to obtain details on the preferences of formation of salts and co-crystal based on the pKa value, the salt and Co-crystal of trimethoprim and sulfamethazine along some heterocyclic coformers were synthesized, thorough analysis of inter and intra molecular hydrogen bonding features with molecular geometry have been studied. Chapter III, we have synthesized three salt of cytosine molecule with coformers of gallic acid, salicylic acid via Aspirin and thiazole carboxylic acid viz., CYT.GAL, CYT.SAL, CYT.TCA. the strong electrostatic force of attraction between the ionic species by shifting the proton from coformers to cytosine has been characterised by the intermolecular interactions and hydrogen bonding pattern. Chapter IV emphasis on the solvated polymorphs quinidine, in which the solvents participated in the structural part of the unit cell that have specific crystalline arrays, also designated as pseudo polymorphs of quinidine. Three solvates were synthesised and involvement of their interaction with quinidine through hydrogen bonds were studied. Chapter V, Section A describes the in situ Cryo-crystallization studies of low melting organic liquids of three isomeric compounds, namely ortho, meta, and para-trifluoromethyl anilines. Their crystal structures have been analysed for various intermolecular interactions, particularly weak hydrogen bonding interactions. In Section B dimerized 4-amino thiophenol and selenophenol crystal structures have been analyzed for various chalcogen, hydrogen bonds along with other weak interaction. Chapter VI, Section A provides the importance in capturing of CO2 from atmospheric flue gas under the ambient condition by using Primary amines. Three aromatic amine carbamates viz., benzylamine, phenylethylamine, and 3-phenyl propyl iso-structurally and packing pattern were discussed through hydrogen bonding interaction. In Section B, the structure of ethylene diamine carried out by in-situ cryo crystallization, and adsorption of CO2 under the ambient condition as ethylene diamine carbamate have been analysed for its structural features.