Topic
Benzopyran
About: Benzopyran is a research topic. Over the lifetime, 1889 publications have been published within this topic receiving 15235 citations.
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TL;DR: In this article, a new synthesis of the title compound using aryllithium salts as key intermediates is described, mainly based on a cyclization reaction that mimics the process by which it is believed benzopyran rings are formed in nature.
3 citations
TL;DR: The authors showed that diphenyl-nitrite imine gives the pyrazolobenzopyranone (3), benzonitrile oxide and N-benzylideneaniline N-oxide yield derivatives (6) and (7) of 2,3-bbenzoxazepin-1-one, and p-nitrophenyl azide forms a mixture of 2-p-nitro-3-(N-pyrrolidinecarbonyl)phthalimidine (10) and N-(p-n-
Abstract: 3-Pyrrolidino-2-benzopyran-1-one behaves differently towards various 1,3-dipoles : diphenyl-nitrite imine gives the pyrazolobenzopyranone (3), benzonitrile oxide and N-benzylideneaniline N-oxide yield derivatives (6) and (7), respectively, of 2,3-benzoxazepin-1-one, and p-nitrophenyl azide forms a mixture of 2-p-nitrophenyl-3-(N-pyrrolidinecarbonyl)phthalimidine (10) and N-(p-nitrophenylcarbamoyl)pyrrolidine (13).
3 citations
Patent•
20 Nov 1975
TL;DR: In this article, the authors proposed substituted [4-oxo-4H-1-benzopyran-2-yl]cyclopropane carboxylic acids and esters having the following structural formula: ##STR1## wherein R 1, R 2, R 3 and R 4 are hydrogen, alkyl, lower alkoxy, phenyl or when R 1 and R 2 are hydrogen and R 3 form an additional aromatic ring and A is hydrogen or ethyl.
Abstract: The present invention relates to substituted [4-oxo-4H-1-benzopyran-2-yl]cyclopropane carboxylic acids and esters having the following structural formula: ##STR1## wherein R1, R2, R3 and R4 are hydrogen, alkyl, lower alkoxy, phenyl or when R1 and R2 are hydrogen, R3 and R4 taken together form an additional aromatic ring and A is hydrogen or ethyl. The compounds of this invention exhibit anti-allergy properties and are indicated in the management of allergic manifestations such as bronchial asthma.
3 citations
01 Apr 1996
3 citations
Patent•
05 Jan 1982
TL;DR: A benzopyran compd. of formula I, where R1 and R2 are each H, straight-chain or branched alkyl, halogen, cyano, (carbo)alkoxy, aryl (oxy), acetoxy-substd. as discussed by the authors.
Abstract: NEW MATERIAL:A benzopyran compd. of formula I, wherein R1 and R2 are each H, straight-chain or branched alkyl, halogen, cyano, (carbo)alkoxy, aryl (oxy), acetoxy-substd. alkyl, cycloalkyl or phenyl, where R1 and R2 may constitute a heterocyclic residue in combination with each other; X is imino or O; Y, and Y2 are halogen; m and n are 1-3 where m+n=2-4. USE:A colorant for coloring a fiber or a molded product consisting of an org. high- molecular material in bright red with excellent fastness. PREPARATION:It is obtd. by the reaction of an imino-coumarin of formula II with a malonodinitrile of formula III in an org. solvent (e.g.,dimethyl-formaldehyde) at 50-200 deg.C, followed by hydrolysis in the presence of an acid, e.g., HCl.
3 citations