Showing papers on "Benzopyrans published in 1990"

Variation in the aromatic ring of cromakalim: antihypertensive activity of pyranopyridines and 6-alkyl-2H-1-benzopyrans.

Abstract: The synthesis and antihypertensive activity in the spontaneously hypertensive rat of two new series of analogues related to cromakalim (1) are described. In the first series, where the benzopyran nucleus has been replaced by a pyranopyridine nucleus, the position of the nitrogen atom has been found to be critical for activity, and the most potent compounds are the pyrano[3,2-c]pyridines. In the second series, where the powerful electron-withdrawing cyano group of compound 1 has been replaced by alkyl and phenyl groups, the order of antihypertensive potency is ethyl, isopropyl, tert-butyl greater than propyl, cyclopentyl greater than methyl greater than phenyl.

Structure-activity relationship of antiestrogens. Studies on 2,3-diaryl-1-benzopyrans

Abstract: A series of 2,3-diaryl-1-benzopyran analogues substituted at position 4 of 2-phenyl with a hydroxy or pyrrolidinoethoxy residue were synthesized as models for (E)-triarylpropenones constrained in the s-trans conformation. The prototypes, belonging to five chemical series, were evaluated for their estrogen receptor affinity and for estrogen agonist-antagonist activities. The 4H-1-benzopyran-4-one, the 2,3-dihydro-4H-1-benzopyran-4-one, the 4H-1-benzopyran, and the 2,3-dihydro-1-benzopyran derivatives were found to be inactive or only marginally activate as receptor ligands or estrogen agonists-antagonists. In the 2H-1-benzopyran category the parent phenol was also inactive whereas the basic ethers 16 and 26 were modest receptor ligands while being quite active as antiestrogens. In a comparative study the benzopyran 16 was found to be more effective antiestrogen than tamoxifen while being as effective as LY-117018. The benzopyrans have thus emerged as a new class of potent antiestrogens.

Structure-activity relationship of antiestrogens. Phenolic analogues of 2,3-diaryl-2H-1-benzopyrans.

Abstract: Phenolic analogues of 2-[4-(2-piperidinoethoxy)phenyl]-3-phenyl-2H-1-benzopyran (1), a novel antiestrogen, were synthesized and evaluated for their structure-activity relationship. Incorporation of OH at position 7 was found to improve receptor affinity of the benzopyran while having no effect on its action as an antagonist. Similar substitution of 2-phenyl as well potentiated receptor affinity as well as antagonist activity of the prototype. The monophenol 19 and the diphenol 25 were thus found to be good receptor ligands, devoid of estrogen agonist activity and associated with marked antiestrogenic activity of comparable order. Both caused nearly complete inhibition of the estradiol stimulated uterine growth in rats as well as mice and were thus found to be better antiestrogens than tamoxifen, trioxifen, and LY-117018. A binding-site model for estrogen receptor rationalizing the structure-activity relationship of benzopyrans in relation to that of the triarylethylene and the triarylpropenone antiestrogens has been discussed.

A Convenient Synthesis of 3-Chloro-3,4-dihydro-4-hydroxy-3-nitro-2-phenyl-2H-1-benzopyrans

Abstract: The novel title compounds 5 are prepared by a simple and efficient two-step procedure starting from substituted benzaldehydes 1. A convenient route to the (2-chloro-2-nitroethenyl)benzenes 3 required as intermediates in the synthesis is reported.

Novel benzopyrans and process for their production

Abstract: The present invention provides compounds of formula I wherein R 1 and R 2 , which may be the same or different, are each -H, -OH, alkoxy of 1 to 17 carbon atoms or alkoxycarbonyl of 2 to 18 carbon atoms and R 3 is are useful in the treatment of an estrogen dependent condition such as breast cancer.

Synthese von Pyrano[3,2-b][1]benzopyranen aus 1-Nitroglycalen

Abstract: Synthesis of Pyranol [3,2-b][1]benzopyrans from 1-Nitroglycals A synthesis of pyrano[3,2-b][l]benzopyrans β-addition of salicylic aldehyde to 1-nitroglycals, followed by a Henry reaction, is described. This sequence gave the cis-annelated pyranobenzopyranes 9 and 11 from 5 in 54 and 9% yield, respectively, demonstrating the pronounced diastereoselectivity of the β-addition. Reductive denitration of the crude product mixture yielded 14(75%), 15(15%), and 16(7%), which were oxidized to the aryl ketones 20 and 21, respectively. Reduction of 20 (NaBH4) gave exclusively 15. The ketone 20 was deprotected to 22 and 23.

2-oxo-1,2-(dihydropyridyl)-2h-1-benzopyrans

Abstract: The present invention is directed to compounds of formula (I) and pharmaceutically acceptable salts thereof: ##STR1## wherein Y, R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , a and b are as defined in the Specification, having pharmacological activity, to a process for their preparation, and to their use as pharmaceuticals.

Novel antihypertensive benzopyran derivatives

Abstract: Disclosed herein are novel benzopyrans having pharmacological activity, a process for preparing them, pharmaceutical compositions containing them, and their use in the treatment of hypertension.

A Convenient Synthesis of 3-Chloro-3,4-dihydro-4-hydroxy-3-nitro-2-phenyl-2H-1-benzopyrans.

Abstract: The novel title compounds 5 are prepared by a simple and efficient two-step procedure starting from substituted benzaldehydes 1. A convenient route to the (2-chloro-2-nitroethenyl)benzenes 3 required as intermediates in the synthesis is reported.

Process for the preparation of chiral 3,4-epoxy benzopyrans

Abstract: A process for the preparation of a compound of formula (A)' or (A)'': which process comprises the base treatment of a quaternary ammonium salt of a compound of formula (D): wherein the NH₂ and OH moieties are trans and are (R,S) or (S,R), respectively.

An Unusual Hydroxyl Inversion Mediated by DAST.

Abstract: Trans -3-hydroxy-4-(2-oxopyrrolidin-1-yl) benzopyrans have been shown to undergo inversion to cis -3-hydroxy-4-(2-oxopyrrolidin-1-yl) benzopyrans in moderate yield on treatment with diethylaminosulphur trifluoride (DAST).

Lewis Acid-Mediated Nucleophilic Substitution Reactions of 2-Alkoxy-3,4-dihydro-2H-1-benzopyrans: Regiochemistry and Utility in the Synthesis of 3,4-Dihydro-2H-1-benzopyran-2-carboxylic Acids.

Abstract: Les substitutions nucleophiles des chromannes du titre avec le [cyano trimethyl] silane sont etudiees. Le catalyseur, TiCl 4 ou SnCl 4 , a une influence sur la regioselectivite des reactions

Synthesis of New Benzopyrans Related to Podophyllotoxin.

Abstract: Mannich bases of types 1 or 8, which are readily synthesized by condensation of 3,4-methylenedioxyphenol with aromatic aldehydes and pyrrolidine or piperazine, react with cyclic and acyclic β-diketones to yield benzopyrans. These benzopyrans are structurally similar to podophyllotoxin and like this drug some of the benzopyrans show in vivo anti-leukemic action in mice.

Antihypertensive benzopyran compounds

Abstract: Disclosed herein are novel benzopyrans having pharmacological activity, to a process for preparing them, to pharmaceutical compositions containing them, and to their use in the treatment of hypertension.

Process for preparing benzopyran derivatives

Abstract: Disclosed herein are novel benzopyrans having pharmacological activity, to a process for preparing them, to pharmaceutical compositions containing them, and to their use in the treatment of hypertension.

Benzopyrans for use in recording systems

Abstract: Benzopyrans of the formula ##STR1## where X is a radical ##STR2## and R1, R2, R3, R4 and the ring A have the meanings stated in the description, a process for their preparation, and their use in pressure-sensitive or heat-sensitive layers.