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Synthesis of Isoidide through Epimerization of Isosorbide using Ruthenium on Carbon
Author(s) -
Le Nôtre Jérôme,
van Haveren Jacco,
van Es Daan S.
Publication year - 2013
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201200714
Subject(s) - catalysis , ruthenium , isosorbide , selectivity , chemistry , hydrogen , dichloromethane , substrate (aquarium) , solvent , inorganic chemistry , chemical engineering , organic chemistry , oceanography , engineering , geology
A highly efficient procedure for obtaining resin‐grade isoidide through catalytic epimerization of isosorbide using a ruthenium‐on‐carbon (Ru/C) catalyst is reported. A comprehensive reaction‐parameter variation study involving substrate concentration, catalyst (type of metal, support, and loading), initial pH value, hydrogen pressure, solvent, and reaction temperature demonstrates that superior performance and high selectivity can be achieved. Epimerization of isosorbide in water (pH 8) at 220 °C, under 40 bar of hydrogen, and using a Ru/C catalyst (5 % Ru) for 2 h results in a thermodynamic equilibrium mixture containing 55 % isoidide, 40 % isosorbide, and 5 % isomannide. In comparison with previously reported nickel‐based catalysts, the Ru/C catalyst is advantageous because it is highly active (as low as 360 ppm Ru) and recyclable. High purity isoidide is obtained by high‐vacuum distillation of an equilibrium mixture on a 200 g scale. The high substrate loading (50 wt % in water), high selectivity, and the possibility for substrate reuse makes this procedure highly atom efficient and therefore, highly attractive for industrial use.