Abstract: The present disclosure relates to a method for preparing isophorone diamine by means of a hydrogenation reduction of isophorone nitrile imine. The hydrogenation reduction is continuously carried out in a multi-stage bubble column reactor loaded with a supported alkaline cobalt-based catalyst, wherein isophorone nitrile imine is successively in countercurrent contact with hydrogen in each stage of the reactor to carry out a hydrogenation reduction reaction, so as to obtain the isophorone diamine. The preparation method solves the problem of back-mixing, and further improves the conversion rate and the cis/trans ratio of the product.

Abstract: A method for synthesizing sucrose-6-ester includes: (a) in the presence of a polar aprotic solvent, contacting an organic phosphine compound represented by formula I with sucrose and an organic tin compound; (b) removing water to obtain a reaction liquid containing a tin-sucrose adduct; and (c) contacting the reaction liquid containing the tin-sucrose adduct with an acid anhydride compound to prepare a sucrose-6-ester. In formula I, R1, R2, and R3 each are a linear or branched alkyl having 1 to 20 carbon atoms, a cycloalkyl having 3 to 10 carbon atoms, or an aryl having 6 to 10 carbon atoms; moreover, the R1, R2, and R3 are identical groups, partially identical groups, or different groups from each other. According to the method, the reaction conversion rate and selectivity are greatly improved; moreover, it is easy to realize industrial application.