1804-90-6

Upstream product

• 106338-64-1 2-hydroxy-7,8,3',4'-tetramethoxyisoflavanone 
• 61243-86-5 2-(3,4-dimethoxyphenyl)-1-(2-hydroxy-3,4-dimethoxyphenyl)ethanone 
• 4637-24-5 N,N-dimethyl-formamide dimethyl acetal 
• 77287-34-4 formamide 
• 93-40-3 (3,4-Dimethoxyphenyl)acetic acid 
• 5150-42-5 2,3-dimethoxyphenol 
• 94413-08-8 3',4'-dimethoxy-7,8-methylenedioxyisoflavone 
• 59092-90-9 maxima isoflavone A 
• 5396-18-9 2'-hydroxy-3',4'-dimethoxyacetophenone 
• 110048-37-8 3',4',7,8-tetramethoxyflavanone 
• 485-72-3 7-Hydroxy-3-(4-methoxy-phenyl)-chromen-4-on 
• 1157-39-7 7-methoxy-3-(4-methoxyphenyl)-4H-chromen-4-one 
• 486-66-8 daidzein 
• 124-41-4 sodium methylate 

Relevant academic research and scientific papers

A valuable route to benzopyrane[4,3-c]isoquinolines

A direct synthesis of benzopyrane[4,3-c]isoquinolines 4 employing isoflavanone 2 as starting material is described. An alternative route for the preparation of dihydrobenzopyrane[4,3-c]isoquinolines 11 is also reported.

Enantioselective Synthesis of Isoflavanones and Pterocarpans through a RuII-Catalyzed ATH-DKR of Isoflavones

Noyori-Ikariya RuII complexes promoted the one-pot C=C/C=O bonds reduction of isoflavones using sodium formate as the hydrogen source through Asymmetric Transfer Hydrogenation-Dynamic Kinetic Resolution (ATH-DKR). Due to the neutral conditions employed, isoflavones with different substituents at the 2’-position of B-ring (H, OH, OMe and Br) were successfully reduced. Ten cis-3-phenylchroman-4-ols were selectively obtained (>20 : 1 dr) in good yields (up to 86 %) and excellent enantioselectivities (up to >99 : 1 er). The synthetic applications of these chiral compounds were also demonstrated. Enantioenriched isoflavanones were obtained under mild metal-free oxidation of the cis-3-phenylchroman-4-ols while pterocarpans were synthesized by two strategies: an acid-catalyzed cyclization and a novel approach based on a Pd-catalyzed C?O intramolecular cross-coupling reaction.

Synthetic method of polyhydroxy isoflavone

The invention discloses a synthetic method of polyhydroxy isoflavone. The method comprises the following steps: (1) reacting 4', 7-dimethoxyisoflavone with N-bromosuccinimide, and controlling the molar ratio of 4', 7-dimethoxyisoflavone to N-bromosuccinimide and a reaction temperature to enable one or two hydrogen atoms on a 4', 7-dimethoxyisoflavone carbon ring to be substituted by bromine atomsto generate corresponding bromide; (2), enabling the bromide in the (2) to react with sodium methoxide under the action of cuprous salt to enable bromine atoms on a carbon ring of the bromide to be substituted by methoxy to obtain a methoxylation product; and (3), carrying out a demethylation reaction on the methoxylation product obtained in the (3) under the action of aluminum chloride and dimethyl sulfide to obtain polyhydroxy isoflavone. The method has the advantages of abundant sources of initial raw materials, mild reaction conditions, good selectivity and high yield, and is suitable forindustrial production. The purity of the product is greater than 99.0%, and the product can be used for pharmacological activity research.

Synthesis of isoflavones containing naturally occurring substitution pattern by oxidative rearrangement of respective flavanones using thallium(III) p-tosylate

Claisen condensation of substituted 2′-hydroxyacetophenones 1a-c with aromatic aldehydes affords respective substituted 2′-hydroxychalcones 2a-n which on base catalyzed cyclization in pyridine:methanol:water (1:1:1) give respective flavanones 3a-n. The oxidative rearrangement of flavanones with thallium(III) p-tosylate furnishes respective isoflavones 4a-n in overall 62-72% yields starting from 1. The present methodology has been successfully applied for the synthesis of naturally occurring isoflavones such as di-O-methyldaidzein 4a, cabruvin 4b, pseudobabtigenin methylether 4d, 5,7-dimethoxyisoflavone 4f, 5,7,4′-trimethoxyisoflavone 4g, derrustone 4i, 7,8,3′,4′- tetramethoxyisoflavone 41, purpuranin-A 4m and 7,8,3′,4′,5′- pentamethoxyisoflavone 4n and thus the first synthesis of 4n is reported.

NINE ISOFLAVONES FROM TEPHROSIA MAXIMA

The isolation and characterisation of nine closely related 3',4'-disubstituted isoflavones from the aerial parts and roots of Tephrosia maxima are reported.Four of these compounds are new natural products, one of which contains a 7,8-methylenedioxy group, an uncommon feature in naturally occurring isoflavones. 1H and 13C NMR data are given for all compounds.Key Word Index -- Tephrosia maxima; Leguminosae; maxima isoflavones A, C, D, E, F and G; 1H and 13C NMR spectra.