The Research Of Multicomponent Reaction Under Solvent-free Condition

In recent years, environmental issues have increasingly become the focus of international society.Social sustainable development demands the designed chemical processes with a view of reduction or evenelimination the use and production of hazardous materials. We have being interested in designing a greenprocess for its production. It is essential for traditional chemical reaction due to good solubility for organiccompounds. It is well-known that organic solvents are flammable, explosive and volatile. No matterdischarging or reclaiming, it will be harmful to the environment. So it is very necessary to find an effectiveway to solve this problem. Recent studies have focused on the limiting the use of organic solvents andreplacing them with new environmentally friendly solvent and solvent-free conditions.Multicomponent reaction (MCR) processes, in which three or more reactants were combined inone-pot, products that incorporate substantial portions of all the components, naturally comply with manyof these stringent requirements for ideal organic synthesis. In recent years, it is regarded as one of the mostwidely studied and applied synthetic methodologies in chemical and related areas.Here we report our results of the synthesis of MCR under solvent-free condition. The effects ofreaction conditions for the yield such as reaction temperature, reaction time and raw materials molar ratioon the reactions are investigated.(1) Five1-amidoalkyl2-naphthols were synthesized by multi-component one-pot condensationreactions of2-naphthol, arylaldehydes and acetamide with potassium bisulfate as catalyst without solvent.The optimum conditions obtained about N-[phenyl-(2-hydroxy-napthalen-1-y1)-mehty1]-acetamide(AAN)were as follows: reaction time40min, reaction temperature90℃, n(2-naphthol): n(benzaldehyde):n(acetamide): n(potassium-bisulfate)=1:1.2:1.2:0.05, the yield of the product reached92.1%. Theproducity ranges of the others were from69.1%to94.0%.(2) A series of2’-aminobenzothiazolo-arylmethyl-2-naphthols were synthesized by three-componentof aromatic aldehyde,2-aminobenzothiazole and2-naphthol under solvent-free conditions. The optimumconditions obtained about2’-aminobenzothiazolo-phenylmethyl-2-naphthols were as follows: reactiontemperature80℃, n(2-naphthol): n(benzaldehyde): n(2-aminobenzothiazole)=1:1.1:1, reaction time40min, The yield of the product was90.1%.(3) O,O’di-ethyl-α-substitutedphenylamino-(substituted-phenylmethyl) phosphonate were synthesizedby one-pot condensation reactions of O,O’-diethylphosphite, aromatic aldehydes and aromatic amines. Theoptimum conditions obtained about one-pot condensation reactions of arylaldehydes, aniline andO,O’-diethylphosphite were as follows: reaction time2h, reaction temperature100℃, n(benzaldehyde):n(Phenylamine): n(O,O’-diethylphosphite)=1:1:1.2, the yield of the product reached57.7%. Theproducity ranges of the others were from51.1%to76.0%. (4) N-(2-benzothiazolyl)-α-aminophosphonates were synthesized by one-pot condensation reactions ofbenzaldehyde,2-aminobenzothiazole, and O,O’-diethylphosphite.under solvent-free conditions withoutcatalyst. n(benzaldehyde): n(2-aminobenzothiazole): n(O,O’-diethylphosphite)=1.2:1:1.2, reaction time3h, reaction temperature100℃, the yield of the product reached56.4%.