Showing papers on "Benzopyrans published in 1996"

Photochromic substituted naphthopyran compounds

Abstract: Described are novel reversible photochromic naphthopyran compounds, examples of which are 3H-naphtho[2,1-b]pyrans having an acyl or aroyl oxy-bearing substituent at the number 6 carbon atom and certain substituents at the 3-position of the pyran ring. Certain substituents may also be present at the number 5, 7, 8, 9 or 10 carbon atom of the naphthopyran. These compounds may be represented by graphic formula (I). Also described are polymeric organic host materials that contain or that are coated with such compounds. Optically clear articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., certain other naphthopyrans, benzopyrans, and spiro(indoline) type compounds, are also described.

Furo-fused 2H-chromenes: synthesis and photochromic properties

Abstract: New photochromic chromenes annulated with a furan ring have been synthesized. Thus, suitable heterocyclic phenols react with different propargylic alcohols in acidic medium to give the corresponding ethers, which cyclize into benzopyrans by thermal Claisen rearrangement. This synthetic approach was found to lead to a mixture of linear and angular chromenes that is strictly related to the nature of the phenol. However, regiospecificity could be obtained by reacting β-phenylcinnamaldehyde, in refluxing aprotic nonpolar solvents, with titanium(IV) salts of the former phenols. Electrocyclization of intermediately generated o-quinoid structures occurs on the α position towards the heterocyclic junction. All compounds exhibit photochromic behavior at room temperature. Furo-fused benzopyrans are particularly interesting with respect to naphthopyran parents in view of the bathochromically shifted and broadened absorption spectra of photoinduced forms. This trend is confirmed by the spectral data of several hetero...

Method for isomerization of arylpropargyl ether monomers and uses therefor

Abstract: In accordance with the present invention, it has been discovered that arylpropargyl ethers can readily be isomerized to produce benzopyrans, by subjecting a defined group of aryl propargyl compounds to isomerization conditions in suitable solvent Invention isomerization process allows the production of a good yield of a variety of benzopyran materials, free of contaminating diluent Benzopyrans prepared in accordance with the present invention are useful for the preparation of adhesive compositions, microelectronic devices, and the like

A Facile Synthesis of Angularly-Fused 3, 4, 4a, 10b-Tetrahydro-2H, 5H-pyrano[3, 2-c][1]benzopyrans by the One-pot Condensation between Salicylaldehydes and Unsaturated Alcohols

Abstract: Salicylaldehydes reacted with 5-methyl-4-hexen-1-ol (4a) or 6-methyl-5-hepten-2-ol (4b) in benzene in the presence of trimethyl orthoformate and a catalytic amount of p-toluenesulfonic acid at rt to give angularly-fused trans-5,5-dimethyl-3,4,4a,10b-tetrahydro-2H,5H-pyrano[3,2-c][1]benzopyrans (6) in high yields with complete stereoselectivity.

Photochromic indeno-fused naphthopyrans

Abstract: Described are novel photochromic indeno-fused naphthopyran compounds, examples of which are naphthopyran compounds having a substituted or unsubstituted indeno group, the 2,1 positions of which are fused to the f side of the naphtho portion of the naphthopyran, and having certain substituents at the 3-position of the pyran ring. Certain substituents may also be present at the number 5, 6, 7, 8, 9, 10, 11, 12 or 13 carbon atoms of the compounds. These compounds may be represented by the following graphic formula: ##STR1## Also described are polymeric organic host materials that contain or that are coated with such compounds. Optically clear articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., certain other naphthopyrans, benzopyrans and spiro(indoline)type compounds, are also described.

Benzopyrans and pharmaceutical compositions containing them

Abstract: The invention provides novel 2,2-di(C1-5alkyl)- or trans-2,2-di(C1-5alkyl)-3,4-dihydro-3-hydroxy- -4-carboxamido-6-(N-arylsulfonamido)-2H-1-benzopyrans; and N-oxides, esters and salts thereof; processes for their production; and their uses as pharmaceuticals, e.g. as K+-channel openers, bronchodilators and agents for the suppression of airways hyperreactivity, e.g., for use in the treatment of asthma.

Recyclization of 2-imino-2h-1-benzopyrans under the influence of nucleophilic reagents. 1. New approach to the synthesis of 3-(1,3,4oxadi-, thiadi-, and triazolyl-2)coumarins

Abstract: It has been found that under the action of hydrazides of carboxylic acids, 2-iminocoumarin-3-carboxamides are recyclized to N(1)-acylamidrazones of coumarin-3-carboxylic acids. The use of N(1)-acylamidrazones is proposed as a simple and effective means of synthesizing 3-(1,3,4-oxadi-, thiodi-, and triazolyl-2)coumarins. The possibilities of alternate schemes of synthesis are discussed, and a mechanism is suggested for the recyclization.

3,4-Dihydro-2-iodomethyl-2,5,7,8-tetramethyl-2H-1-benzopyrans

Abstract: The present invention refers to compounds having a benzopyranic structure of general formula I ##STR1## wherein R represents a hydrogen atom or an acyl group, useful as intermediates in the synthesis of vitamin E and of other compounds having benzopyranic structure endowed with properties inhibiting the formation of organic peroxides and therefore having antioxidizing activity, and to the process for their preparation.

Benzopyran antagonists to leucotriene B4

Abstract: Benzopyran antagonists to leucotriene B4. This invention relates to: New benzopyrans and other fused benzo-rings which are antagonists of leucotriene B4 corresponding to formula I where R1 is a phenyl or substituted phenyl group and A, n, R2 and R3 are as defined in the description. Useful in the treatment of industrial diseases due to leucotriene B4.

Dioxirane Oxidation of Benzopyrans, Benzothiopyrans and Related Compounds

Abstract: Dioxiranes are shown to be powerful and convenient oxidation agents for benzopyrans, benzothiopyrans, and α, β-unsaturated ketones.

Stereochemical Preferences and Requirement for the 3‐Hydroxyl Group in Novel Anticonvulsant 4‐Fluorobenzoylamino Benzopyrans.

Abstract: A cis 3 S ,4 S isomer, derived stereospecifically from an anticonvulsant trans 3 R ,4 S -( para -fluorobenzoylamino)-benzopyran using the DAST reagent, has been shown to possess anticonvulsant properties. In contrast the cis 3 R ,4 R enantiomer did not possess anticonvulsant properties but caused blood pressure to fall.