Properties and applications of four butyl urea

　　The molecular formula of four butyl urea is C17H36N2O, with a relative molecular weight of 284.5. TBU at room temperature and under atmospheric pressure is a colorless to light yellow, odorless liquid, melting point, boiling point < 50 DEG 310~315 DEG C, 20 DEG C when the density of 0.87g/cm3, the vapor pressure is 10Pa, the flash point of 140 DEG C, auto ignition temperature of 205 DEG C. TBU is almost insoluble in water, and the partition coefficient is 5.3 in octanol and water at 20 centigrade. TBU non-toxic, rats orally LD50 17g/kg, the human eye, skin and respiratory system has a certain stimulating effect. Four butyl urea intermediates in organic synthesis is a very versatile, can be used for the preparation of pesticide, medicine, dye, plastic plasticizer and stabilizer, phosgenation reaction catalyst and solvent and lubricating oil; can also substitute for toxic phosphoric acid amide additives for preparing amino plastic, use the most important instead of phosphoric acid in the synthesis of hydrogen peroxide by anthraquinone process in three ester (TOP) used as working liquid solvent.

　　There are many methods for the synthesis of TBU, TBU, most of which are reacted with the corresponding amine (two butyl amine) with phosgene and other carbonyl reagents. Because the widely used carbonylation reagents, such as phosgene and sulfuric acid two methyl esters, are highly toxic and highly toxic chemicals, the research and development of their substitutes have attracted much attention, [1]. Phosgene (COCl2) is a kind of important acylation reagent, which is widely used in the preparation of important fine chemicals such as isocyanate, carbonic acid ester and carbamate. By two amine with phosgene in the presence of alkali was prepared by the reaction of TBU, is currently the most widely used method, the reaction is as follows: 2 (C4H9) 2NH + COCl2 + 2NaOH - (C4H9) 2N - CO - N (C4H9) 2 + 2NaCl + H2O W. A. Skinner [2] TBU in the study of insect repellent synthesis when using benzene as solvent, two amine, phosgene and K2CO3 to 35 DEG C, by element analysis knowledge product is TBU. H., Jochem and [3] believe that the conventional batch gasification process for synthesizing TBU has the disadvantages of high labor intensity, low yield of space and time and high process cost. They introduced a process of continuous phosgene production of TBU, using 2 tandem stirred tank reactor, the continuous raw material balance is introduced into the reactor, by adjusting the mixing ratio of raw materials, reaction temperature and pH value, and the appropriate means of using organic solvent, the formation of a 2 phase mixture in the reactor at the end of the product; mixture by phase separation, washing and distillation to obtain the pure TBU. The method can effectively improve the space time yield of the reactor.

　　Phosgene has the advantages of simple process and easy availability of raw materials. But it also has some disadvantages, such as phosgene toxic, storage and transportation difficulties, high equipment requirements and large amount of "three wastes". In order to diphosgene technology for production of diphosgene under room temperature is a colorless transparent liquid, the chemical name of trichloromethyl chloroformate (TCF), miscible with most organic solvents, can use [4] instead of phosgene in organic synthesis. When it is used to synthesize TBU, TCF is first decomposed into 2 molecules, COCl2, and then reacted with two. The drawback of this approach is extremely volatile, double light toxicity is strong, operation is difficult to control.