Patent ID: 7700785
Filing Date: 2010-04-20
Classification: C07C

Abstract:
1. A process for preparation of dialkyl carbonate, comprising the step of: performing oxidative carbonylation of an alcohol in liquid phase in the presence of CO and O imidazole derivative of formula (I): wherein R 1 , R 2 , R 3 and R 1 are independently selected from the group consisting of hydrogen, halogen, cyano, amino, C 1-6 alkylamino, C 1-12 alkyl, C 1-12 alkoxy, C 1-12 alkanoyl, C 3-12 cycloalkyl, C 3-12 cycloalkyloxy, C 3-12 cycloalkylacyl, C 6-20 aryl C 7-20 aralkyl and C 7-20 alkylaryl; wherein C 1-6 alkylamino, C 1-12 alkyl, C 1-12 alkoxy, C 1-12 alkanoyl, C 3-12 cycloalkyl, C 3-12 cycloalkyloxy, C 3-12 cycloalkylacyl, C 6-20 aryl, C 7-20 aralkyl and C 7-20 alkylaryl may be further substituted by halogen, nitro or cyano; provided that at least one of R 1 , R 2 , R 3 and R 4 is not hydrogen; pyridazine derivative of formula (III): wherein R 1 , R 2 , R 3 and R 4 are independently selected from the group consisting of hydrogen, halogen, nitro, cyano, amino, C 1-6 alkylamino, C 1-12 alkyl, C 1-12 alkoxy, C 1-12 alkanoyl, C 3-12 cycloalkyl, C 3-12 cycloalkyloxy, C 3-12 cycloalkylacyl, C 6-20 aryl, C 7-20 aralkyl and C 7-20 alkylaryl; wherein C 1-6 allylamino, C 1-12 alkyl, C 1-12 alkoxy, C 1-12 alkanoyl, C 3-12 cycloalkyl, C 3-12 cycloalkyloxy, C 3-12 cycloalkylacyl, C 6-12 aryl, C 7-20 aralkyl and C 7-20 alkylaryl may be further substituted by halogen, nitro or cyano.