Safe and Convenient Procedure for Solvent Purification

TLDR

The paper presents a general method for purifying solvents used in air‑ and moisture‑sensitive reactions. The method degasses solvents in large reservoirs, then passes them through two columns—activated alumina to remove protic contaminants and a copper catalyst to eliminate trace oxygen—before collecting them anhydrously via a glove box or Schlenk manifold. The procedure offers a nonhazardous, rapid alternative to distillation, producing oxygen‑free solvents at ppm levels, and is adaptable for gas purification or small‑scale deuterated solvent preparation.

Abstract

This contribution describes a general method for the purification of solvents for use with air and moisture sensitive reactions. This procedure provides a nonhazardous alternative to distillations and vacuum transfers and does not require undue supervision or cooling, yet allows for the rapid collection of large quantities of extremely pure solvents on demand. Solvents are rigorously degassed in 18 L reservoirs and passed through two sequential purification columns. Protic contaminants are removed with activated alumina, while a supported copper catalyst is used to remove trace oxygen from hydrocarbons. The purification system is interfaced with either a glove box or Schlenk manifold for the anhydrous/anaerobic collection of solvents. Solvents purified by this method and tested with stock solutions of sodium benzophenone ketyl or titanocene dichloride/zinc dust are free of oxygen at least to the ppm level. Furthermore, this system may be used for the in-line purification of gases and is easily scaled down to provide a convenient method for the purification of deuterated solvents or other reagents.