Patent ID: 7709686

Claim:
A process for preparing glutaraldehyde, the process comprising: (a) reacting in a vessel at from 80° C. to 120° C. a reaction mixture comprising an alkoxydihydropyran compound of formula I wherein R is C 1 -C 20 alkyl, water, and an acidic catalyst to form glutaraldehyde and the alcohol corresponding to the alkoxydihydropyran compound's alkoxy group; (b) removing from the reaction mixture a distillate comprising the alcohol and unreacted alkoxydihydropyran compound, wherein said removal is effected with a distillation column; (c) contacting the distillate with a heterogeneous catalyst located externally to the distillation column such that at least a portion of the alkoxydihydropyran compound reacts therein; and (d) returning at least a portion of the distillate of step (c) to the distillation column.