A facile one-pot, economical approach to 1,2,3-thiadiazol-5-ylureas was developed via seleniumcatalyzed oxidative carbonylation of 1,2,3-thiadiazol-5-amine with a series of amines in one-pot manner in the presence of ...A facile one-pot, economical approach to 1,2,3-thiadiazol-5-ylureas was developed via seleniumcatalyzed oxidative carbonylation of 1,2,3-thiadiazol-5-amine with a series of amines in one-pot manner in the presence of CO and O_2. This approach is featured with cheap and easily available raw materials,cheap and reusable catalyst selenium, one-pot procedure, high atomic economy, simple operations and no emission of corrosive wastes.展开更多
2-(5-Amino-1,2,4-thiadiazol-3-yl)-2-(Z)-meth-oxyiminoacetic acid 2-benzothiazolyl thioester(III),an important intermediate of the fourth generation cephalos-porins,was efficiently synthesized by reacting 2-(5-amino-1,...2-(5-Amino-1,2,4-thiadiazol-3-yl)-2-(Z)-meth-oxyiminoacetic acid 2-benzothiazolyl thioester(III),an important intermediate of the fourth generation cephalos-porins,was efficiently synthesized by reacting 2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(Z)-methoxyiminoacetic acid(I)with 2,29-dibenzothiazole disulfide(II)in the presence of triphenylphosphine.Effects of reaction time,temperature,solvents,catalysts and feeding molar ratio on the yield and quality of products were investigated,and an im-proved procedure suitable for industrial production was established.Using 1,2-dichloroethane as solvent,triphe-nylphosphine as reducer,and triethylamine as catalyst,n(I):n(II):n(triphenylphosphine)51.0:1.0:1.0,the product was obtained at room temperature in 98.1%yield.The purity of the product without further purification is 98.7%determined by HPLC method.This procedure could be a suitable alternative to the traditional processes because of its easy handling,high yield and low cost.展开更多
2-（Hydrazinecarbothioyl）-N-substituted hydrazinecarbothioamides react with 2,3,5,6-tetrachloro-1,4-benzoquinone in high yields in a novel fast and facile method to give 5-unsubstituted-1,3,4-thiadiazole-2-amine deri...2-（Hydrazinecarbothioyl）-N-substituted hydrazinecarbothioamides react with 2,3,5,6-tetrachloro-1,4-benzoquinone in high yields in a novel fast and facile method to give 5-unsubstituted-1,3,4-thiadiazole-2-amine derivatives.The synthesized compounds were characterized by spectroscopic methods and confirmed by using X-ray crystallography.A rationale for the formation of the products is presented.展开更多
基金financial support from the National Natural Science Foundation of China(No.21772033)Program for Innovative Research Team in Science and Technology in University of Henan Province(No. 15IRTSTHN003)
文摘A facile one-pot, economical approach to 1,2,3-thiadiazol-5-ylureas was developed via seleniumcatalyzed oxidative carbonylation of 1,2,3-thiadiazol-5-amine with a series of amines in one-pot manner in the presence of CO and O_2. This approach is featured with cheap and easily available raw materials,cheap and reusable catalyst selenium, one-pot procedure, high atomic economy, simple operations and no emission of corrosive wastes.
文摘2-(5-Amino-1,2,4-thiadiazol-3-yl)-2-(Z)-meth-oxyiminoacetic acid 2-benzothiazolyl thioester(III),an important intermediate of the fourth generation cephalos-porins,was efficiently synthesized by reacting 2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(Z)-methoxyiminoacetic acid(I)with 2,29-dibenzothiazole disulfide(II)in the presence of triphenylphosphine.Effects of reaction time,temperature,solvents,catalysts and feeding molar ratio on the yield and quality of products were investigated,and an im-proved procedure suitable for industrial production was established.Using 1,2-dichloroethane as solvent,triphe-nylphosphine as reducer,and triethylamine as catalyst,n(I):n(II):n(triphenylphosphine)51.0:1.0:1.0,the product was obtained at room temperature in 98.1%yield.The purity of the product without further purification is 98.7%determined by HPLC method.This procedure could be a suitable alternative to the traditional processes because of its easy handling,high yield and low cost.
文摘2-（Hydrazinecarbothioyl）-N-substituted hydrazinecarbothioamides react with 2,3,5,6-tetrachloro-1,4-benzoquinone in high yields in a novel fast and facile method to give 5-unsubstituted-1,3,4-thiadiazole-2-amine derivatives.The synthesized compounds were characterized by spectroscopic methods and confirmed by using X-ray crystallography.A rationale for the formation of the products is presented.
