Synthesis Of N-Vinylsulfonamides And Pyrimidine-2-Amines Using Calcium Carbide As A Solid Alkyne Source

As a cheap and readily available solid material,calcium carbide is mainly used in the production of acetylene gas in industry.As a common alkyne source,acetylene is an important raw material for a variety of synthetic conversion.However,due to the flammable and explosive safety risks of gaseous acetylene and the use of high pressure reactor and other valuable equipment in the reaction process,the reaction operation process has some difficulties.Therefore,it is necessary to explore a green and safe,cheap raw materials,simple and easy to obtain,easy to operate and mild reaction conditions to replace gaseous acetylene in the synthesis of a variety of organic compounds.Recent studies show that calcium carbide as a green solid raw material can directly replace acetylene gas in many organic synthesis.However,the exploration of more efficient organic synthesis reaction of calcium carbide is still to be further in-depth.N-Vinyl arylsulfonamide is a multifunctional compound that contains vinyl,sulfonyl,amide and phenyl in one molecule and is an important intermediate in the synthesis of dyes,textiles,pharmaceuticals and plastics.The reported synthetic methods of N-vinyl arylsulfonamides still have some shortcomings:for example,the use of flammable and explosive gaseous acetylene as the source of acetylene at high temperature and high pressure makes the operation unsafe and the equipment complicated;the use of precious metal catalysts and commercially unavailable raw materials makes synthesis costly and cumbersome.Therefore,it is necessary to explore a simpler and more practical method to synthesize N-vinyl arylsulfonamides.4-Arylpyrimidine-2-amine compounds have a wide range of biological and drug activities,such as anti-tumor,antibacterial,anti-HIV,anti-fungal and anti-tuberculosis values in varying degrees.Pyrimidines are also potential candidates for photophysical materials.With regard to the synthesis of 4-arylpyrimidine-2-amines,the reported synthetic methods still have some drawbacks,such as the use of commercially unavailable starting materials with alkynes,which have to be pre-synthesized using acetylene gas as the original source,and the use of expensive catalysts.Therefore,it is still necessary to explore a simple method to synthesize 4-arylpyrimidine 2-amines by using simple acetylene source,low cost catalyst and simple operation.In this thesis,the new methods for the synthesis of N-vinyl arylsulfonamides from arylsulfonamides and 4-arylpyrimidine 2-amines from aromatic aldehydes and guanidine by using calcium carbide as a solid alkyne source instead of gaseous acetylene were investigated.These methods use a simple acetylene source and easy-to-handle experimental operation,and avoid the use of noble metal catalyst.This paper has done the following aspects of workFirst hand work:The research progress of the direct use of calcium carbide as an acetylene source in organic synthesis are reviewed.Secondary work:The synthesis of N-vinyl arylsulfonamides with calcium carbide as acetylene source by addition reaction with arylsulfonamides under alkaline conditions were studied.Eighteen compounds were obtained with good to high yield,and their structures were characterized by ¹H NMR,¹³C NMR and HRMS.This method has the advantages of simple operation,short reaction time,cheap and easy raw materials,easy post-treatment,high product yield and good functional group tolerance.Third aspect of work:The synthesis of 4-arylpyrimidine 2-amines from guanidine and aromatic aldehydes by using calcium carbide as a safe and easy-to-handle solid alkyne source through a one-pot three-components procedure under the catalysis of copper was studied.Eleven compounds were obtained with good yield,and all compounds were characterized by ¹H NMR,¹³C NMR and HRMS.The main advantage of this method is is the use of green,safe,cost saving and easy to operate starting materials.This method provides a safe,simple and novel alternative to the synthesis of 4-arylpyrimidine-2-amines.