Showing papers on "Benzopyran published in 1983"

Synthesis and antihypertensive activity of substituted trans-4-amino-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-3-ols.

Abstract: A series of novel 6,7-disubstituted trans-3,4-dihydro-2, 2-dimethyl-4-pyrrolidino-(or piperidino)-2H-1-benzopyran-3-ols was prepared and tested for antihypertensive activity in the conscious spontaneously hypertensive rat (SHR) and compared with certain of their monosubstituted analogues. The potent blood pressure lowering activity of the 6-monosubstituted compounds was enhanced by incorporation of an acetylamino or amino group at C(7) and that of the 7-nitro-substituted compound by incorporation of an amino (but not an acetylamino group) at C(6). The combination of 6-nitro or 6-cyano with 7-(acetylamino) or 7-amino groups and 6-amino with 7-nitro groups in trans-4-pyrrolidino- or -4-piperidino-2,2-dimethyl-2H-1-benzopyranols conferred superior antihypertensive activity to hydralazine and to the calcium antagonist, nifedipine, in SHR. The synthetic route to these compounds involves the conversion of 2H-1-benzopyrans to bromohydrins that were treated with pyrrolidine or piperidine. Preparation of the 6-cyano-7-amino analogue was accomplished when 6-cyano-7-[(trifluoroacetyl)amino]-2,2-dimethylbenzopyran was used as starting material.

1H-2-benzopyran-1-one derivatives, microbial products with pharmacological activity. Relationship between structure and activity in 6-[[1(S)-(3(S),4- dihydro-8-hydroxy-1-oxo-1H-2-benzopyran-3-yl)-3-methylbutyl]-amino]-4(S), 5(S)-dihydroxy-6-oxo-3(S)-ammoniohexanoate.

Abstract: In order to investigate the structural requirements for gastroprotective activity in 6-[[1(S)-(3(S),4-dihydro-8- hydroxy-1-oxo-1H-2-benzopyran-3-yl)-3-methylbutyl]amino]-4(S),5(S)-dihydroxy 6-oxo-3(S)-ammoniohexanoate [AI-77-B, 1], a product of Bacillus pumilus AI-77, nine derivatives were prepared and then tested for protective activity against stress-induced ulcers in rats. Neither the chromophore, [1-(3,4-dihydro-8-hydroxy-1-oxo-1H-2-benzopyran-3-yl)-3-methylbutyl]ammonium chloride (2), nor the side-chain moiety, 4-amino-2,3-dihydroxyhexanedioic acid (4), as separate fragments alone showed any significant activity. Hydrolysis of the lactone ring of the 1H-2-benzopyran-1-one skeleton, to give 6-[[1-(2-carboxy-3-hydroxyphenyl)-2-hydroxy-5-methylhex-3-yl]amino]-4, 5-dihydroxy-6-oxo-3-ammoniohexanoate (5), led to a considerable decrease in activity. The formation of a gamma-lactone ring in the side chain, 4-[1-hydroxy-2-[[1-(3,4-dihydro-8-hydroxy-1-oxo-1H-2-benzopyran-3-yl) -3-methylbutyl]-amino]-2-oxoethyl]butan-4-olid-3-yl]ammonium chloride (6), resulted in a small decrease in activity. Selective acetylation at the primary amine position of 6, to give 4-[1-hydroxy-2- [[1-(3,4-dihydro-8- hydroxy-1-oxo-1H-2-benzopyran-3-yl)-3-methylbutyl]amino]-2-oxoethyl]-3- (acetylamino)butan-4-olide (7), led to a considerable decrease in activity. Both di- and triacetylated derivatives of 6, 4-[1-acetoxy-2 -[[1-(3,4-dihydro-8-hydroxy-1-oxo-1H-2-benzopyran-3-yl)-3-methylbutyl] amino]-2-oxoethyl]-3-(acetylamino)butan-4-olide (8) and 4-[1-acetoxy-2- [[1-(3,4- dihydro-8-acetoxy-1-oxo-1H-2-benzopyran-3-yl)-3-methylbutyl]amino]-2- oxoethyl]-3-(acetylamino)butan-4-olide (9), were inactive. Selective methylation of the phenolic hydroxyl group of to give 1, 6-[[1-(3,4-dihydro-8-methoxy-1-oxo-1H-2-benzopyran-3-yl) -3-methylbutyl]amino]-4,5-dihydroxy-6-oxo-3-ammoniohexanoate (15), resulted in a small decrease in activity. On the other hand, conversion of the carboxyl group of the side chain to an amide, to give [6-[[1-(3,4-dihydro-8-hydroxy-1-oxo-1H-2-benzopyran-3-yl)- 3-methylbutyl]amino]-4,5-dihydroxy-6-oxo-3-hexanamido]ammonium chloride (10), caused a considerable increase in both activity and toxicity. The findings showed that modifications at the position of the amino acid moiety of 1 significantly influenced the activity and that the 1H-2-benzopyran-1-one skeleton was also required for activity to occur.

2,4-diamino-(substituted-benzopyran(quinolyl,isoquinoly)methyl)pyrimidines useful as antibacterials

Abstract: Novel 2,4-diaminopyrimidines having substituted heterobicyclomethyl moieties in the 5-position have superior antibacterial properties

Heterocyclic systems. Part 14. Condensation reactions of 2-(4-oxo-4H-1-benzopyran-3-yl)-1,3-dioxolane

Abstract: Nitrogen nucleophiles under 1,4-addition with the title acetal (4; R = H, Me, and Cl) to give an intermediate that ultimately produces in most cases the same product as is obtained from the corresponding aldehyde (3) under similar conditions. Thus, compound (4) condenses with piperidine and morpholine to give the enamino ketone (14; R1R2=–[CH2]5–, –[CH2]2O[CH2]2–), with aniline to give the chromanone (15; Z = H, Me, and OMe), and with o-phenylenediamine to give the dihydrodiazepine (16), the latter being dehydrogenated to the unsaturated compound (17) by boiling in acetic acid. On being refluxed with hydrazine (5) in pyridine, the acetal (4; R = H) affords smoothly the benzoylpyrazole (20; R′= H, Ph), whereas (4; R = Me or Cl) even with equimolar proportions of hydrazine in refluxing ethanol gives predominantly, if not exclusively, the pyrazole (25; R′= H, Ph). Guanidine and urea with (4) give the fused aminopyrimidine (33) and the hydroxy analogue, respectively.

3,4-dihydro-2h-benzopyran derivatives, a method of producing them, a method of using them as stabilizers for organic materials, and organic compositions containing such stabilizers

Abstract: There is provided a class of novel 3,4-dihydro-2H-benzopyran derivatives which either have excellent inhibitory activity against unfavorable effects of heat, light and oxidative factors or are of use as precursors of compounds having such activity, and methods for producing these derivatives. Also provided are methods of using such 3,4-dihydro-2H-benzopyran derivatives as stabilizers for organic materials sensitive to heat, light or/and oxidative factors, and organic compositions containing such stabilizers.

Three syntheses of 3,8-dimethyl-1H-pyrano[4,3-b][1]benzopyran-10-one, a model for the synthesis of the fungal metabolite, fulvic acid

Abstract: Compouds with the 1H-pyrano[4,3-b][1]benzopyran-10-one nucleus characteristic of fulvic acid have been prepared by three methods from chromone precursors; the characteristic steps are (i) the acetylation of the 2-methyl group of 3-methoxymethyl-2,6-dimethylchromone by acetyl chloride and lithium di-isopropylamide at –70 °C, (ii) the acetylation of the 2-methyl group of 3-chloromethyl-2,6-dimethylchromone by N,N-dimethylacetamide in phosphoryl chloride followed by acid hydrolysis, and (iii)(the best route) the reverse Diels–Alder addition of 2-methoxypropene to 3-formyl-6-methylchromone and the rhodium-catalysed isomerisation of the product to regain the chromone nucleus.

Benzopyran, benzothiapyran and quinoline compounds and pharmaceutical compositions containing them

Abstract: These are described compounds of formula I, in which X is -0-, -S- or -NR 3 -, R 3 is hydrogen or alkyl C 1 to 6, A is -COOH or 5- (1H-tetrazolyl), and B is hydrogen, or A and B together form a chain -N= N -NH-, n 1 is nyarogen or nyaroxy, R 2 is hydroxy or esterified hydroxy, R 6 is hydrogen or alkyl C 1 to 3, R 7 is hydrogen or methyl, and R 8 is alkyl C 1 to 4 optionally substituted by phenyl, provided that when B is hydrogen, A is-COOH, X is-0-, R 1 is hydrogen, R 2 is hydroxy, R 6 and R 7 are both hydrogen then R 8 is not propyl, and pharmaceutically acceptable derivatives thereof. There are also described methods for making the compounds and pharmaceutical, e.g. gastric acid secretion inhibiting, compositions containing them.

Photocontrols of alkali metal salt permeation with 1-octadecyl-3,3-dimethyl-6'-nitrospiro(indoline-2,2'-2H-benzopyran)-blended membrane.

Abstract: Photocontrols of Alkali Metal Salt Permeation with 1-Octadecyl-3,3-dimethyl-6′-nitrospiro(indoline-2,2′-2 H -benzopyran)– Blended Membrane

Naphthalene and 2-oxo-benzopyran acids and derivatives and pharamaceutical use thereof

Abstract: There are described compounds of formula I, ##STR1## in which Ra, Rb, Rc, Rd, Re, Rf and Rg, which may be the same or different, each represent hydrogen, amino, hydroxy, alkoxy, alkenyloxy, halogen, acyl, alkenyl, alkyl, or alkoxy substituted by phenyl, Rh is hydrogen, alkyl or --COOH. X is a hydrocarbon chain containing from 2 to 10 carbon atoms and optionally substituted by a hydroxy group, A has no significance or represents Y, OY, or SY and Y represents a C 1 to 4 hydrocarbon chain which is optionally substituted by alkyl C 1 to 4, E and G, which may be the same or different, each represent --O--, --S-- or --CH 2 --, provided that at least one of E and G is --O-- or --S--, L, together with the carbon atoms to which it is attached, forms a benzene, furan, thiophene, pyrrole, or pyran-2-one ring, and pharmaceutically acceptable derivatives thereof.

Reactivity of 2-methylene-1,3-dicarbonyl compounds. Syntheses of 2,2,3-trisubstituted-3,4-dihydro-2H-pyrano(3,2-c)(1)benzopyran-5-ones.

Abstract: Michael condensation of 2-methylsulfinylmethyl-1, 3-dicarbonyl compounds (3) or 2-methylene-1, 3-dicarbonyl compounds (4) with 4-hydroxycoumarin (5) at ambient temperature gave 2-[(4-hydroxycoumarin-3-yl)methyl]-1, 3-dicarbonyl compounds (6). Treatment of 6 with methanolic hydrogen chloride resulted in the regioselective formation of 2, 2, 3-trisubstituted-3, 4-dihydro-2H-pyrano[3, 2-c][1]benzopyran-5-ones.

Regioselective synthesis of 4,10-dihydro-3-hydroxy-3-methyl-1H,3H-pyrano[4,3-b][1]benzopyran-10-one, the basic skeleton in fulvic acid

Abstract: The first synthesis of 4,10-dihydro-3-hydroxy-3-methyl-1H,3H-pyrano[4,3-b][1]benzopyran-10-one, the basic skeleton in fulvic acid, was achieved by sequential cyclization, which involved hydrogenation of the boron complex of the dione (5) obtained by regioselective cyclization of the acetal (4) with HCl in tetrahydrofuran.

Preparation of 3,4-dihydro-2h-benzopyran derivative

Abstract: PURPOSE:To obtain the titled compound especially useful as a stabilizer for synthetic resins using inexpensive raw materials easily, by reacting a pyran derivative with an acid derivative in the presence of Lewis acid to give an alkene derivative, reacting it with a hydroquinone derivative in the presence of Lewis acid CONSTITUTION:A pyran derivative shown by the formula I (one of X and Z is H and the other together with Y forms a bond) is reacted with an acid derivative shown by the formula II (R is organic group; Q is halogen, or R COO; R is organic group) in the presence of Lewis acid to give an alkene derivative shown by the formula III, which is reacted with a hydroquinone shown by the formula IV (R is H or protecting group; R is H or lower alkyl; R and R are H, lower alkoxy of lower alkyl; R and R form CH=CHCH=CH) in the presence of Lewis acid to give a 3,4-dihydro-2H-benzopyran derivative shown by the formula V, which is prepared easily from the easily and inexpensively obtainable compound shown by the formula I

Halogen-substituted benzopyran- and benzothiopyran-4-carboxylic acids, their preparation and pharmaceutical compositions containing the same

Abstract: of EP0011426Benzopyran- and benzothiopyran-4 -carboxylic acid aldose reductase inhibitors of the formula: or a pharmaceutically acceptable salt thereof, wherein x is 0, S, S = O or n is zero or one; R is hydrogen or alkyl of 1 to 4 carbon atoms; R1 is hydrogen, chloro, bromo, fluoro or phenyl; R2 and R3 when taken individually, are each hydrogen, alkyl of 1 to 3 carbon atoms, chloro, bromo or fluoro; and when taken together, R2, R3 and the carbon atoms to which they are connected form a fused benzene ring; with the proviso that at least one of R1, R2 and R3 is chloro, bromo or fluoro. The compounds are useful in the treatment of diabetic-associated complications, such as cataracts, neuropathy or retinopathy, in a diabetic host. Also disclosed are methods for preparing the compounds of the formula (I) and their salts, and pharmaceutical compositions containing them.

Three syntheses of 3,8‐dimethyl‐1h‐pyrano(4,3‐b)benzopyran‐10‐one, a model for the synthesis of the fungal metabolite, fulvic acid

Abstract: Durch Chlormethylierung von (Ia) zu (Ib) und anschliesende Umsetzung mit Methanol/Base erhalt man (lc), das zu einem Gemisch aus (II) und (IIIa) umgesetzt wird.

Regioselective synthesis of 4,10-dihydro-3-hydroxy-3-methyl-1h,3h-pyrano(4,3-b)(1)benzopyran-10-one, the basic skeleton in fulvic acid

Abstract: The first synthesis of 4,10-dihydro-3-hydroxy-3-methyl-1H,3H-pyrano[4,3-b][1]benzopyran-10-one, the basic skeleton in fulvic acid, was achieved by sequential cyclization, which involved hydrogenation of the boron complex of the dione (5) obtained by regioselective cyclization of the acetal (4) with HCl in tetrahydrofuran.