Dihydroquinazolin-4(3H)-ones were synthesized by the reaction of o-nitrobenzamides with aromatic aldehydes or cyclones promoted by the low-valent titanium reagent(TiCl 4-Zn system). The products were characterized by ...Dihydroquinazolin-4(3H)-ones were synthesized by the reaction of o-nitrobenzamides with aromatic aldehydes or cyclones promoted by the low-valent titanium reagent(TiCl 4-Zn system). The products were characterized by elementary analysis, IR, 1H NMR and X-ray single crystal diffraction. This method possesses the advantages of easily accessible starting materials, convenient manipulation and moderate to high yields.展开更多
In this paper, it was found that isopropylidene (1-hydroxy-3-oxo-butylidene) malonate 4 was a heat unstable compound and the one step convenient methods for preparation of 4-hydroxy-6-methyl-2-pyrone 1 and 3-carboxy-4...In this paper, it was found that isopropylidene (1-hydroxy-3-oxo-butylidene) malonate 4 was a heat unstable compound and the one step convenient methods for preparation of 4-hydroxy-6-methyl-2-pyrone 1 and 3-carboxy-4-hydroxy-6-methyl-2-pyrone 2 in good yields were reported. Isopropylidene malonate 3、diketen and triethylamine reacted in chloroform to give 2, and in the mixture of dichloromethane and chlorobenzene to offer 1.展开更多
3,4Dehydro3hydroxy4phenylpyran2,5dione is an important intermediate of benzoquinones which have the ability to reduce plasma level of glucose.We selected a novel method to prepare the intermediate from...3,4Dehydro3hydroxy4phenylpyran2,5dione is an important intermediate of benzoquinones which have the ability to reduce plasma level of glucose.We selected a novel method to prepare the intermediate from phenylacetyl chloride in this paper.The facile synthetic scheme put forward in this paper is simple to operate and has the characteristic of high yield and good feasibility.展开更多
文摘Dihydroquinazolin-4(3H)-ones were synthesized by the reaction of o-nitrobenzamides with aromatic aldehydes or cyclones promoted by the low-valent titanium reagent(TiCl 4-Zn system). The products were characterized by elementary analysis, IR, 1H NMR and X-ray single crystal diffraction. This method possesses the advantages of easily accessible starting materials, convenient manipulation and moderate to high yields.
文摘In this paper, it was found that isopropylidene (1-hydroxy-3-oxo-butylidene) malonate 4 was a heat unstable compound and the one step convenient methods for preparation of 4-hydroxy-6-methyl-2-pyrone 1 and 3-carboxy-4-hydroxy-6-methyl-2-pyrone 2 in good yields were reported. Isopropylidene malonate 3、diketen and triethylamine reacted in chloroform to give 2, and in the mixture of dichloromethane and chlorobenzene to offer 1.
文摘3,4Dehydro3hydroxy4phenylpyran2,5dione is an important intermediate of benzoquinones which have the ability to reduce plasma level of glucose.We selected a novel method to prepare the intermediate from phenylacetyl chloride in this paper.The facile synthetic scheme put forward in this paper is simple to operate and has the characteristic of high yield and good feasibility.
