US Patent 7161046 Process for the preparation of alkylene glycols

Disclosed is a process for the preparation of alkylene glycols from the corresponding alkylene oxide, such as ethylene glycol from ethylene oxide, in the presence of water, a catalyst and, optionally, carbon dioxide. The catalyst is a SALEN-type compound which contains an amino group and an oxy or hydroxy group connected by a hydrocarbon, such as an alkyl or an alkylaryl. The SALEN-type compounds may be Schiff bases, i.e., a condensate product of a primary amine with an aldehyde, ketone or an alcohol. The SALEN-type compound may be a mono or bis compound and may be complexed with a Group 4-14 metal, such as aluminum, tin, vanadium, chromium, manganese, iron, cobalt or platinum.