31964-91-7

Upstream product

• 16636-62-7 1-(2'-hydroxyphenyl)butane-1,3-dione 
• 4637-24-5 N,N-dimethyl-formamide dimethyl acetal 
• 39079-62-4 chromone-3-carboxylic acid 
• 196201-78-2 (E)-2-(2-Dimethylaminovinyl)-1-benzopyran-4-one 
• 55168-31-5 2-methyl-4-oxo-4H-1-benzopyran-3-carboxaldehyde 
• 1190871-08-9 3-((trimethylsilyl)ethynyl)-4H-chromen-4-one 
• 17422-74-1 3-Formylchromone 
• 93598-96-0 2-Dimethylaminomethylene-1-(2-hydroxyphenyl)butan-1,3-dione 

Relevant academic research and scientific papers

A base-promoted desalicyloylative dimerization of 3-(1-alkynyl)chromones: An unusual approach to 2-alkynyl xanthones

A novel base-promoted cascade desalicyloylative dimerization of 3-(1-alkynyl)chromones to produce 2-alkynyl xanthones has been developed. This tandem process involves multiple reactions, such as Michael additions/ cyclizations/desalicyloylation without a transition metal catalyst and inert atmosphere.

Benzopyrans : Part 40 - Alumina mediated transformations of 4-oxo-4H-1- benzopyran-3-carbaldehyde, -3-carboxylic acid and their 2-methylhomologues

In contact with alumina, the title aldehyde 1 (R = H, Me, Cl) gives the chromones 5 and 9,12 whereas the acid 2 affords the chromones 7, 10 and acetophenone 23. Alumina converts the aldehyde 3 to the xanthone 14, and the corresponding acid 4 to the chromone 8 and diketone 24.

Benzopyrans. Part 41.1 Reactions of 2-(2-dimethylaminovinyl)-lbenzopyran-4-ones with various dienophiles

Dienamine 1 with W-phenylmaleimide and chromenone 14 as well as 15 produces, through initial [4 + 2]cycloaddition, xanthenones 10 and 18, respectively. Initial Michael addition of 1 to chromenones 14 and 16, and dimethyl acetylenedicarboxylate (DMAD), triggers the formation of xanthenone 19, 4-azaxanthenone 26 and substituted fumarate 49, respectively. Initial [2 + 2]cycloadducts of dienamines 1-3 with electrophilic acetylenes always undergo further transformations. Thus, 1 with DMAD, dibenzoylacetylene and ethyl propiolate (EP) ultimately gives xanthenones 33, 34 and 37, respectively, the latter being admixed with flavone 43. Enamine 2, cyclisable to xanthenone 11, gives 33 and 35 with DMAD, and 37 and 44 with EP. Reaction of 3 with DMAD affords 36 exclusively. The Royal Society of Chemistry 1999.

Benzopyrans: Part XVI - Reaction of 1-(2-Hydroxyphenyl)butan-1,3-dione with Dimethylformamide Dimethyl Acetal

1-(2-Hydroxyphenyl)butan-1,3-dione (1, X= H and Me) with dimethylformamide dimethyl acetal gives the enaminodiketone (2') in benzene but the xanthone derivative (8) in methanol medium.Refluxing in alcohol converts 2' into 8 whereas acid treatment of 2' produces 3-acetylchromone (5).