Studies On Selenium-catalyzed Carbonylation To Chlorpropham,benzylurea And L,4-dihydro-2h-3,l-benzoxazin-2-ones

Nowadays, Se/CO catalytic system arouses broad attention. First, expensive metal can be replaced bythe cheap available nonmetal selenium catalyst, and phosgene can be replaced by low cost carbonmonoxide as carbonylation agent. Second, the efficient Se/CO catalyst which can be recycled worked as thephase transfer catalyst in the reaction process. The last, selenium-catalyzed carbonylation reaction hasmany advantages such as mild reaction conditions, simple operation and so on. Se/CO catalytic system canbe used to synthesize some symmetrical and unsymmetrical ureas, carbamates, etc, which are importantchemicals in agricultural chemicals and medicines. In this paper, we synthesized chlorpropham (CIPI),dibenzylurea and1,4-Dihydro-2H-3,1-benzoxazin-2-one which enlarged the useness of seleniumcatalyzed carbonylation reaction.The chemical name of Chlorpropham is isopropyl3-chlorophenyl carbamate (CIPI).Chlorpropham, with a wide application in agriculture, can be used as plant growth regulator and herbicides.For the low toxicity, it is safe for human and so on. Therefore, much attention was payed to it for a longtime. Herein, a green and facile approach was described to synthesize CIPI via the reaction of isopropanoland m-chloronitrobenzene in the presence of selenium catalyst in one pot. To get the optimised conditions,the influences of reaction time, reaction temperature, reaction pressure, the proportion of substrates andbases were investigated. Under the optimised conditions, the1-chloro-3-nitrobenzene was converted in100%yield and the Chlorpropham was obtained in91.7%yield.Urea is an important category of chemicals and most of them bear bio-activity which attracts muchattention. In this paper, the selenium-catalyzed oxidative carbonylation of benzylamine to synthesize1,3-dibenzylurea was reported. The main factors influencing the carbonylation such as reaction time, reactiontemperature, CO/O₂pressure, and the content of selenium, different kinds of bases, reaction solvents andmethods were investigated. The conversion yield of benzylamine was up to100%and the yield of1,3-dibenzylurea was91.7%under optimized reaction conditions. At the same time, a series of dibenzylureaswere synthesized under the optimized reaction conditions.1,4-Dihydro-2H-3,1-benzoxazin-2-one is an important category of chemicals. Then, many strateges for the synthesis of ureas were reported in the literature, such as the method employed transition metals ascatalyst etc. Here, the selenium-catalyzed oxidative carbonylation of (2-aminophenyl)methanol to1,4-Dihydro-2H-3,1-benzoxazin-2-one was described. The main factors influencing the carbonylation suchas temperature, time, reaction solvents, content of catalyst, different kinds of bases, content of co-catalystand CO/O₂pressure were investigated in this reaction. The1,4-Dihydro-2H-3,1-benzoxazin-2-one wasobtained in86.5%yield.In this paper, we synthesized chlorpropham(CIPI), dibenzylurea and1,4-Dihydro-2H-3,1-benzoxazin-2-one which enlarged the useness of selenium catalyzed carbonylation reaction. It is valuablefor both academic work and industry.