Synthesis Of 4-arylethyl-6-arylpyrimidine-2-thiols And Aza-michael Additions Of 3-aminopyrazole With Nitroalkenes

Pyrimidine-2-thiol derivatives are widely used in medicinal chemistry due to their important biological activity.For unsubstituted pyrimidine-2-thiols,the conventional synthesis method is obtained by reacting 1,1,3,3-tetraethoxypropane with thiourea in a strong acid medium.Only Habibi reported synthesis of a reaction between ?-enamine and thiourea under alkaline conditions.In recent years,studies have mainly focused on the synthesis of the pyrimidine-2-thiol tautomer,pyrimidine2-(1H)-thione,from the reaction of chalcone with thiourea.Aza-Michael addition reaction and Michael addition reaction are important methods for the synthesis of C-N bond and C-C bond.Aza-Michael addition reaction in which nitroene is a Michael acceptor and a 3-aminopyrazole is a Michael donor will give rise to important organic compounds containing multiple functional groups such as nitro,amino and pyrazole rings;Dienone is a Michael acceptor,and the Michael addition reaction of phenethylnitrile as a Michael donor also yields important organic compounds that contain multiple functional groups such as cyano,alkenyl,and carbonyl groups.However,these two types of reactions have not yet been reported in the literature.This article mainly studied the synthesis of 4-arylethyl-6-arylpyrimidine-2-thiol by aza-Michael addition/nucleophilic addition/aromatization reaction and3-aminopyridine without catalytic conditions.Aza-Michael addition reaction of oxazoles and ?-nitrostyrene,while Michael addition reaction of phenylacetonitrile and diketene is also reported.the synthesis of 4-arylethyl-6-arylpyrimidine-2-thiol by aza-Michael addition/nucleophilic addition/aromatization reaction without catalytic3-aminopyrazole and Aza-Michael addition reaction of ?-nitrostyrene,also reported Michael addition reaction of phenylacetonitrile and diketene.This article is mainly described in four chapters:Chapter ?: Reviewed the synthesis and application of pyrimidine-2-thiol and the aza-Michael addition reaction of pyrazole-containing compounds and theirapplications.Chapter ?: Explored a series of 4-arylethyl-6-aryl pyrimidines were synthesized via aza-Michael addition/nucleophilic addition/aromatization series reaction of dienone and thiourea with KOH as catalyst.This method uses only a simple inorganic base catalyzed reaction,the reaction conditions are mild,the yield is high,and the atomic utilization is good.Chapter ?: Explored the catalysis-free Michael addition of 3-aminopyrazole and ?-nitrostyrene-aza.A series of products containing a pyrazole ring and a nitro group were obtained.This method does not require any catalyst,the conditions are mild,and the yield is high.Chapter ?: Explored the selective Michael addition of phenylacetonitrile and diketene under the catalyst conditions of DBU,and a series of(E)-3-(2-oxo-2-arylethyl)-2,5-diarylpent-4-enenitrile.were obtained.This method has mild conditions and high yields.