Deep eutectic solvents (DESs) are solvents that moreover to having the properties of g reen solvents due to properties such as easy synthesis, low melting point, stability towards moisture and air, low vapor pressure, and high thermal stability can be used as an alternative to ionic liquids (IL)[1]. DESes are be made of mixture a hydrogen-bond acceptors (HBA) and hydrogen-bond donors (HBD). Generally, a DES is a type of solvent composed of a mixing two or more components under simple operation of that forms an eutectic with a much lower melting point than either of the individual components[2]. The piperidine ring system is one of the most found in numerous natural products such as alkaloids, drug candidates and drugs[3]. The piperidine derivatives are abundant in synthetic bioactive molecules as well as in various natural products which exhibit a plethora of biological properties such as analgesic, anticonvulsant, antimalarial, nicotinic and antiinfluenza[4-5]. In this study, a novel, efficient and recoverable DES was designed, made and fully investigated by using Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis/ differential thermal analysis (TGA/DTA), differential scanning calorimetry (DSC), density, eutectic point and 1HNMR. The DES was made of mixture one of the triphenylphosphonium derivatives as HBA and a acidic compound as HBD and used for synthesis derivatives of the piperidine derivatives.
