Tetrahydrofuran (THF), or oxolane, is an organic compound with the formula (CH2)4O. The compound is classified as heterocyclic compound, specifically a cyclic ether. It is a colorless, water-miscible organic liquid with low viscosity. It is mainly used as a precursor to polymers. Being polar and having a wide liquid range, THF is a versatile solvent. It is an isomer of another solvent, butanone.Tetrahydrofuran (THF) 99.5% AR is a high-purity, stabilized, liquid solvent used in chemical analysis and synthesis, with a purity of at least 99.5%. The “AR” stands for “Analytical Reagent,” indicating its suitability for analytical testing and its high quality compared to technical grades.