This book is written especially for researchers at various levels e.g., in Industry, R&D laboratories, university & college laboratories etc. It describes a large number of organic reactions (which were earlier performed using anhydrous conditions and volatile organic solvents. The conditions used are aqueous phase, using PTC catalyst, sonication and microwave technologies. Some reaction carried out enzymatically, solid state and using ionic liquid have also been described. A Large number of preparations using above techniques have been incorporated.