Showing papers on "Benzopyrans published in 1992"
Patent•
22 Oct 1992TL;DR: In this paper, the authors provided compounds of formula "STR1" where R1 and R2 are each --H, --OH, alkoxy of 1 to 17 carbon atoms or alkoxy carbonyl of 2 to 18 carbon atoms and R3 is ##STR2## are useful in the treatment of an estrogen dependent condition such as breast cancer.
Abstract: The present invention provides compounds of formula ##STR1## wherein R1 and R2, 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 R3 is ##STR2## are useful in the treatment of an estrogen dependent condition such as breast cancer.
38 citations
TL;DR: In this paper, a trifluoroacetic acid/water mixture under argon at room temperature is used to synthesize benzopyrans, which can be efficiently synthesized by reacting a phenol and an allylic alcohol in a trifeacetyl acid and water mixture.
23 citations
TL;DR: In this paper, aryl allenylmethyl ethers in diethylene glycol were rearranged to yield 2-(o-hydroxyaryl)buta-1,3-dienes and 4-methyl-2H-1-benzopyrans.
Abstract: Thermal Claisen rearrangement of aryl allenylmethyl ethers in diethylene glycol afforded 2-(o-hydroxyaryl)buta-1,3-dienes and 4-methyl-2H-1-benzopyrans in good yield.
8 citations
Patent•
19 Mar 1992
TL;DR: In this paper, the authors used the formula (I) or pharmaceutically acceptable salts thereof (STR1) for the treatment of hypertension and respiratory tract disorders, where R2 -R7, Y, a and b are as defined.
Abstract: Compounds of the formula (I) or pharmaceutically acceptable salts thereof ##STR1## where R2 -R7, Y, a and b are as defined, are useful in the treatment of hypertension and respiratory tract disorders.
8 citations
TL;DR: In this article, the α,β unsaturated monophosphonate heterocycles were obtained from tetraethyl ethylidene gem-bisphosphonates and 2-hydrocydohexanone, substituted salicylaldehydes or 2hydroxy-1-naphthaldehyde.
Abstract: The preparation of α,β unsaturated monophosphonate heterocycles is reported. 9-diethylphosphono-7-oxabicyclo[4.3.0]non-1(9)-ene, some 3-diethylphosphono-2H-1-benzopyrans and 2-diethylphosphono-3H-naphtol[2,1-b]pyran have been prepared from tetraethyl ethylidene gem-bisphosphonate and 2-hydrocydohexanone, substituted salicylaldehydes or 2-hydroxy-1-naphthaldehyde respectively.
7 citations
TL;DR: In this article, the reaction of electron deficient pyrroles and pyrazoles with trans-3-bromo-6-cyano-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-4-ol under basic conditions results in the formation of 2-isopropylbenzofurans by a mechanism which appears to be dependent on the rate of the competitive dehydration reaction leading to the corresponding benzopyrans.
5 citations
DOI•
01 Dec 1992TL;DR: In this article, the photochemical behavior of 3,4-epoxy-3, 4-dihydro-2H-1-benzopyrans, intermediates in the synthesis of pterocarpans, has been studied in various solvents.
Abstract: Photochemical behaviour of 3,4-epoxy-3,4-dihydro-2H-1-benzopyrans, intermediates in the synthesis of pterocarpans, has been studied in various solvents. While ring contraction leading to 2,3-dihydrobenzofurans through a photodecarbonylation process was observed in cyclohexane, photoisomerisation leading to 3-chromanones was observed in acetone. This study has also been extended to antijuvenile hormone precocene(I) oxide.
Patent•
13 Oct 1992
TL;DR: In this paper, the authors defined a formula (I) wherein A, n, R1, R2 and R3 are as defined in this paper, where A is a c-substituted CR4R5-COOR13 compound by reaction with a trimethylsilyl ketene acetal.
Abstract: Benzopyran and other benzo-fused leukotriene B4 antagonists have formula (I) wherein A, n, R1, R2 and R3 are as defined herein. The compounds of formula (I) wherein R1 is c-substituted CR4R5-COOR13 may be prepared from the corresponding c-substituted CF3SO3 compound by reaction with a trimethylsilyl ketene acetal.
TL;DR: Chromones bearing electron-withdrawing substituents at C-3 react with 2-haloethanols and potassium carbonate in acetone to produce tetrahydrofuro[2,3-b][1]benzopyran-4-ones, the heteroannulation proceeding via the conjugate addition of the haloethanol to the chromone, followed by intramolecular alkylation.
Abstract: Chromones (4-oxo-4H-1-benzopyrans) bearing electron-withdrawing substituents at C-3 react with 2-haloethanols and potassium carbonate in acetone to produce tetrahydrofuro[2,3-b][1]benzopyran-4-ones, the heteroannulation proceeding via the conjugate addition of the haloethanol to the chromone, followed by intramolecular alkylation. Under the conditions of the reaction, the products derived from chromone-3-carbaldehydes undergo in situ deformylation.
TL;DR: In this article, a trifluoroacetic acid/water mixture under argon at room temperature is used to synthesize benzopyrans, which can be efficiently synthesized by reacting a phenol and an allylic alcohol in a trifeacetyl acid and water mixture.
Abstract: Benzopyrans can be efficiently synthesized by reacting a phenol and an allylic alcohol in a trifluoroacetic acid/water mixture under argon at room temperature. The procedure is widely applicable and allows benzopyrans to be synthesized rapidly.