Open AccessA Versatile Method of Ambient-Temperature Solvent Removal
Author(s) -
Igor V. Kolesnichenko,
Galina Goloverda,
Vladimir Kolesnichenko
Publication year - 2019
Publication title -
organic process research and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.904
H-Index - 109
eISSN - 1520-586X
pISSN - 1083-6160
DOI - 10.1021/acs.oprd.9b00368
Subject(s) - solvent , gravimetric analysis , distillation , chemistry , evaporation , dimethyl sulfoxide , dimethylformamide , liquefaction , chromatography , chemical engineering , organic chemistry , thermodynamics , engineering , physics
Isolation of heat-sensitive reaction products in post-synthesis workup procedures often requires ambient-or low-temperature solvent removal. In the method demonstrated here, solvent evaporation is driven by the pressure gradient between a distillation flask and a chilled receiver in an evacuated closed system containing a minimal amount of residual noncondensable gas. Using an all-glass apparatus, the method is exemplified by evaporation of solvent samples from a distillation flask containing 50 mL of either dimethylformamide, dimethyl sulfoxide (DMSO), or N -methylpyrrolidone (NMP). The distillation flask is suspended in a water bath at temperatures of 18-28 ° C, the evaporated solvent is collected in a receiver chilled with liquid nitrogen, and the entire process is completed in 90-140 min. The practicality of this method is further illustrated on a bench-chemistry scale by DMSO and NMP solvent removal from solutions of benzophenone, monitored by gravimetric and 1 H NMR methods. Modification of the demonstrated method to mimic freeze-drying conditions (by reducing heat flow to the distillation flask) can be used for recovery of water-soluble compounds including polymers and biopolymers. We propose the name "cryovap" for this solvent removal method.