Showing papers on "Benzopyran published in 1997"
155 citations
TL;DR: In this paper, the photoinduced ring-opening process in spiropyran compounds has been modeled through CASSCF calculations on the lowest excited state (S1) of benzopyran.
Abstract: The photoinduced ring-opening process in spiropyran compounds has been modeled through CASSCF calculations on the lowest excited state (S1) of benzopyran. The documented S1 reaction coordinate is characterized by a ring-opening transition state connecting a cyclic intermediate to a much more stable acyclic structure. Remarkably this structure does not correspond to a real S1 intermediate but to a crossing point (i.e., a conical intersection) between the excited- and ground-state energy surfaces. At this crossing the excited-state system can undergo fully efficient decay to S0. Using the parent pyran molecule as a model, we have characterized two ground-state valleys which develop from the crossing point. The first valley leads to reactant (pyran) regeneration. The second valley leads to cZc-penta-2,4-dienal indicating that the primary ring-opened photoproduct is formed in an unstable conformation. The benzopyran/pyran reaction coordinates suggest that the first step in the benzospiropyran photochromic rea...
84 citations
TL;DR: In this article, benzo-fused heterocycles such as indoles, benzofurans, and a benzopyran were obtained using an intramolecular cross-coupling of vinyl halides with phenols.
54 citations
37 citations
Patent•
10 Dec 1997
TL;DR: In this paper, novel water-solvable photochromic naphthopyran and benzopyrin compounds having an alkylamino-alkylamino group on the Naphtho- or benzo-portions and/or pyran portions thereof are described.
Abstract: Described are novel water soluble photochromic naphthopyran and benzopyran compounds having an alkylaminoalkylamino group on the naphtho- or benzo-portions and/or pyran portions thereof. These compounds may be represented by one of the following graphic formulae: ##STR1## wherein R1 is an alkylaminoalkylamino group. Articles such as ophthalmic lenses or other plastic transparencies and coating compositions such as paints and inks that incorporate the novel water soluble compounds are also described.
32 citations
TL;DR: In this paper, a novel intramolecular cyclisation reaction between an organocobalt stabilised cation and a trisubstituted alkene was accomplished to afford a new family of benzopyran derivatives.
28 citations
TL;DR: The photochromic behavior of 3,3-bis[4-(N,N-dimethylamino)phenyl]-3 H -naphtho[2,1-b]pyran (2 ) and 2,2-bis]2 H -1-benzopyran(3 ) has been studied by flash photolysis as mentioned in this paper.
20 citations
Patent•
13 Dec 1997
TL;DR: In this article, a benzopyran derivative having anti-estrogenic activity was presented. But the present invention relates to a novel benzopyanin derivative represented by formula (I) and pharmaceutically acceptable salt thereof.
Abstract: The present invention relates to a novel benzopyran derivative having anti-estrogenic activity. More specifically, the present invention relates to a novel benzopyran derivative represented by formula (I) and pharmaceutically acceptable salt thereof, in which ----- represents a single bond or a double bond; R1 and R2 independently of one another represent hydrogen, hydroxy or OR group, wherein R represents acyl or alkyl; R3 represents hydrogen, lower alkyl or halogeno lower alkyl, provided that when ----- represents a double bond, R3 is not present; R4 represents hydrogen or lower alkyl; A represents a group of formula (a), (b), (c) or (d); R5, R6 and R7 independently of one another represent hydrogen, alkyl, halogenoalkyl, alkenyl or halogenoalkenyl, or R6 and R7 together with nitrogen atom to which they are bound can form a 4- to 8-membered heterocyclic ring which can be substituted with R5; X represents O, S or NR8, wherein R8 represents hydrogen or lower alkyl; m denotes an integer of 2 to 15; n denotes an integer of 0 to 2; and p denotes an integer of 0 to 4, and to a process for preparation thereof and a pharmaceutical composition having anti-estrogenic activity which contains the compound (I) as an active component.
19 citations
TL;DR: In this article, high-selective transformations of 5,6,7,8-tetrahydro-2 H -1-benzopyran-2,5-diones with hydrazides, phenylhydrazines and heterocyclic hydrazines as nitrogen-containing nucleophiles were investigated.
17 citations
TL;DR: In this paper, 2-Aminopyridine, sesamol and 4-hydroxy-3,5-dimethoxybenzaldehyde condense to form Mannic base 3b which reacts with tetronic acid to yield lactone 4c; this inhibits growth of tumors in NCI in vitro tests.
15 citations
TL;DR: The synthesis of three benzopyran quinones containing hydroxy substituents at the 4-position has been achieved as mentioned in this paper, which is the key step in each of these syntheses involved an oxidative mercury-mediated ring closure.
Journal Article•
Patent•
20 Mar 1997
TL;DR: The use of a benzopyran derivative for treating heart diseases such as ischemic heart disease and cardiac arrhythmia is discussed in this paper, where the authors present a safe and effective drug for heart diseases.
Abstract: The present invention offers a safe and effective drug for heart diseases and a safe and effective use of a benzopyran derivative for treating heart diseases such as ischemic heart disease and cardiac arrhythmia. The use of a benzopyran derivative comprises administering a pathologically effective amount of a benzopyran derivative expressed by the following general formula (I):
wherein R 1 is an alkyl group or an alkenyl group, R 2 is a hydrogen atom, an alkyl group, an alkyl group having at least one hydroxyl group, an alkenyl group, an acyl group or a glycosyl group; or physiologically acceptable salts thereof.
TL;DR: In this article, a direct and high yielding route to 2-(5-tetrazolyl)benzopyran-4-ones including pranlukast is described.
TL;DR: In this paper, structural information on the influence of substitution of intracyclic and glycosidic oxygen atoms by sulfur atoms, as well as on influence of aromatic rings and of sulfoxide groups on the carbohydrate moiety is provided.
Patent•
20 Mar 1997
TL;DR: In this paper, the present invention relates to novel benzopyran derivatives of formula (I), wherein A is an oxygen or sulfur atom or a methylene group; B and C are: a) when B is a benzofused heterocycle (a) wherein U is an O, S or N atom, Z-Y are two carbon atoms linked by a double or single bond and T is a single bond, a carbonyl group, C can be a -CONR7-, CSNR7-, -SO2NR 7-, -CH2O-,
Abstract: The present invention relates to novel benzopyran derivatives of formula (I), wherein A is an oxygen or sulfur atom or a methylene group; B and C are: a) when B is a benzofused heterocycle (a) wherein U is an O, S or N atom, Z-Y are two carbon atoms linked by a double or single bond and T is a single bond, a methylene or carbonyl group, C can be a -CONR7-, CSNR7-, -SO2NR7-, -CH2O-, -CH=CH-group; b) when B is a phenyl group (b), C can be a -SO2NR7-, -CH2O-, -CH=CH-group; D is a 5-tetrazolyl or -COOR8 group, wherein R8 is hydrogen, a (C1-C4)-alkyl or phenylalkyl group; and m and n are integers between 0 and 4. Said compounds show a leukotriene-antagonistic activity, and they are valuable as anti-inflammatory and antiallergic medicaments or in the treatment of cardiovascular diseases.
TL;DR: In this article, the synthesis, characterisation and antifeedant activity of new furocoumarins prepared from 4,6-diacetyl resorcinol has been reported.
TL;DR: In this paper, a preferred "in plane" conformation of 4 S (4-fluorobenzoylamino)benzopyran SB-204269 was found to be essential for optimal potency at a unique receptor site.
TL;DR: The authors showed that partial or complete cleavage of the starting material occurs in the course of reaction of 2-oxo-2H 2H 2-CO 2 ] and 1-benzopyran-3-carbonitrile.
Abstract: Synthetic reactions of2-oxo-2H
-1-benzopyran-3-carbonitrile afford productswhich establish that partial or complete cleavage of the startingmaterial occurs in the course of reaction.
TL;DR: In this article, a simple selective transformation of 5,6,7,8-tetrahydro-2H-1-benzopyran-2,5-diones with some phenylhydrazines and heterocyclic hydrazines was described.
Patent•
10 Dec 1997TL;DR: In this paper, the authors presented novel benzopyran derivatives, substituted in position 2 with an adamantyl group as well as the compositions and polymer matrices containing such derivatives.
Abstract: The present invention has for subjects, novel benzopyran derivatives, substituted in position 2 with an adamantyl group as well as the compositions and (co)polymer matrices containing such derivatives. Said derivatives possess interesting photochromic properties.
TL;DR: In this paper, a series of photochromic diaryl benzopyrans fused with benzofuran have been prepared and tested for photo-chromic performance, showing bathochromic shifts in the UV and broad bands in the visible spectra.
Abstract: A series of photochromic diaryl benzopyrans fused with benzofuran have been prepared and tested for photochromic performance The four isomeric hydroxydibenzofurans were coupled with (un)substituted 1,1-diphenyl propargyl alcohols The resulting photochromic products show bathochromic shifts in the UV and broad bands in the visible spectra compared to 2,2-diaryl benzopyrans (2,2-diarylchromenes) It has also been found that the position of the benzofuran fusion has a profound effect on the visible spectrum and fade rate In addition to structure-property relationships, the synthesis of these compounds is discussed
TL;DR: In this article, an asymmetric induction was observed in the one-pot condensation reaction of (S)-(-)-perillaldehyde with 4-hydroxy-6-methyl-2-pyrone in the presence of L-proline which provided the title compound, C 16 H 18 O 3, a tricyclic pyrone, as a single diastereomer in 78% yield.
Abstract: A remarkable asymmetric induction was observed in the one-pot condensation reaction of (S)-(-)-perillaldehyde with 4-hydroxy-6-methyl-2-pyrone in the presence of L-proline which provided the title compound, C 16 H 18 O 3 , a tricyclic pyrone, as a single diastereomer in 78% yield. As the configuration of the cyclohexane C atom holding the isopropenyl group is the same as that in the (S)-aldehyde substrate, the total absolute stereochemistry could be elucidated from its X-ray structure. The cyclohexane ring has a chair conformation in which the juncture H atom (H5a) is axially oriented and the isopropenyl substituent is equatorial.
Patent•
24 Nov 1997
TL;DR: In this paper, a process for the preparation of compounds of formula I: in which: R 1 represents a hydrogen atom or an alkyl radical comprising 1 to 3 carbon atoms, R 2 represents an acyl radical composed of 1 to 4 carbon atoms and X represents O or H 2, of their isomers, as well as of their addition salts with a pharmaceutically acceptable acid or base.
Abstract: Process for the preparation of compounds of formula I: in which: R1 represents a hydrogen atom or an alkyl radical comprising 1 to 3 carbon atoms, R represents a hydrogen atom, an alkyl radical comprising 1 to 4 carbon atoms, or an acyl radical - CO - R' in which R' represents an alkyl radical composed of 1 to 4 carbon atoms, X represents O or H2, of their isomers, as well as of their addition salts with a pharmaceutically acceptable acid or base.
TL;DR: For 2e and 2f, exo-chain addition becomes preferred, and for 2d, endo chain addition much less preferred, than in==================related cases with X = H as mentioned in this paper.
Abstract: Intramolecular Diels–Alder additions of the
2-benzopyran-3-ones 2d, 2e and 2f with an
E-SO2Ph substituent on the
dienophile (X = SO2Ph in 2) show greatly
enhanced exo-addition of the tether than is shown in the
absence of the E-SO2Ph group (X = H in
2). For 2e and 2f, exo-chain addition becomes preferred, and
for 2d, endo-chain addition much less preferred, than in
related cases with X = H. An E-CO2Me
group on the dienophile is also effective in enhancing
exo-chain addition, but less effective than an
E-SO2Ph group. The adducts 4e and 4f undergo
reductive elimination (5% Na–Hg) to give the diterpene related
products 32 and 33 respectively.
TL;DR: The configuration and conformation of all diastereoisomers were studied by combined NMR and computational analyses as discussed by the authors, and a preference for the conformer with both substituents in the pseudo-equatorial orientations was established.
Abstract: The configuration and conformation of cis/trans‐3,4‐dihydro‐2‐alkoxy‐4‐(alkyl‐ or aryl‐substituted)‐2H,5H‐pyrano[3,2‐c][1]benzopyran‐5‐one derivatives were studied by combined NMR and computational analyses. The cis/trans configurational assignments of all diastereoisomers were achieved via 2D NOESY experiments. The conformational analysis of cis compounds, performed via NMR and computational studies, allowed the establishment of a preference for the conformer with both substituents in the pseudo‐equatorial orientations. For trans derivatives only the molecular mechanics analysis produced meaningful results, suggesting a general prevalence for the conformer bearing the 2‐alkoxy group in a pseudo‐axial and the 4‐substituent in a pseudo‐equatorial orientation. © 1997 John Wiley & Sons, Ltd.
Journal Article•
TL;DR: In this article, a unique synthesis of functionalised α-tetralones has emerged from cyclic and acyclic carbon nucleophiles with 2 substituted 1,3-oxazinanes.
Abstract: Acid catalysed condensations of various 2 substituted 1,3-oxazinanes 3 and 1,3-oxazolidines 4 with cyclic carbon nucleophiles viz. 5,5-dimethyl-1,3-cyclohexanedione and 1,3-cyclohexanedione furnish xanthene derivatives, whereas a Knoevenagel reaction proceeds with acyclic nucleophiles. In case of 4b and 4c, a unique synthesis of functionalised α-tetralones has emerged. Reactions of mixtures of cyclic and acyclic carbon nucleophiles with 3 provide some functionalised and partially reduced benzopyran derivatives.
TL;DR: In this paper, a facile one-step synthesis of 2-amino-5-oxo-5,6,7,8-tetrahydro-4H-benzopyran derivatives via cyclo-addition reactions of acrylonitrile derivatives 1a-e with 1,3-cyclohexandione 2 is described.
Abstract: A facile, one-step synthesis of 2-amino-5-oxo-5,6,7,8-tetrahydro-4H-benzopyran derivatives 4a-e via cyclo-addition reactions of acrylonitrile derivatives 1a-e with 1,3-cyclohexandione 2 is described. On the other hand, the reactions of 2 with the thioamides 1f-h afforded 5-oxo-5,6,7,8-tetrahydroquinoline derivatives 9a-c in good yields. The structures of the prepared compounds were established from their elemental analyses, spectroscopic data, and by their chemical transformations. © 1996 John Wiley & Sons, Inc.