55850-49-2

Upstream product

• 90-94-8 bis(p-dimethylaminophenyl)methanone 
• 102164-16-9 1,1-di[4,4'-bis(dimethylamino)phenyl]-2-propyn-1-ol 
• 135-19-3 β-naphthol 

Relevant academic research and scientific papers

Boronic acid/Br?nsted acid co-catalyst systems for the synthesis of 2: H -chromenes from phenols and α,β-unsaturated carbonyls

Protocols for the synthesis of substituted 2H-chromenes from α,β-unsaturated carbonyls and phenols are described. Optimal combinations of arylboronic acids and Br?nsted acids have been identified, such that both can be employed in catalytic quantities to accelerate these condensations. The method has been used to synthesize a variety of substituted 2H-chromenes, as well as photochromic naphthopyrans. The use of pentafluorophenylboronic acid and diphenylphosphinic acid enabled an expansion of the electrophile scope to include α,β-unsaturated ketones. Hall's 'phase-switching' of boronic acids has been exploited to achieve the separation of the two co-catalysts from unpurified reaction mixtures by a simple liquid-liquid extraction.

Functional mesoporous aluminosilicate nanoparticles as host material to fabricate photo-switchable polymer films

Precisely nano-sized aluminosilicate particles (average diameter size 50 to 80 nm) with tailor-made internal surface polarity are suitable as host material for photochromic dyes of the chromene type in order to produce optical transparent photoswitchable polymer films. The sophisticated host material does accomplish two important requirements for a technical application, appropriate internal space for the light induced reversible switching process of the adsorbed dye and suppression of disturbing chemical reactions. The adjustment of the internal surface polarity of the host material was achieved by silane reagents which could be observed by means of specific solvatochromic probes. The Royal Society of Chemistry 2011.

Observations on the synthesis of photochromic naphthopyrans

1-Naphthol reacts with 1,1-diarylprop-2-yn-1-ols 5a,b, under alumina catalysis, by two pathways to give the photochromic naphtho[1,2-b]pyrans 6a,b, together with the propenylidenenaphthalenones 7a,b, representatives of a new class of merocyanine dyes. With 2-methyl-1-naphthol, formation of the photochrome is suppressed; the only products are merocyanines 7c,d. The cyclocondensation of 2-naphthol with 5a,b proceeds much more efficiently, to give the naphtho[2,1-b]pyrans 14a,b. Pyran formation is not suppressed from either 1-bromo- or 1-(4 -methoxyphenyl)-2-naphthol; reaction with 5a,b merely results in expulsion of the C-1 substituent. An alternative pathway supervenes in the reaction of 1-methyl-2-naphthol with 5a to give the benz[e]indanone 17, the constitution of which was determined by X-ray crystallography. Reaction of the 1,3,3-triarylpropynols 19a,b with 1-naphthol affords the naphthopyrans 20 together with merocyanines 21, whilst the isomeric pyrans 23 are efficiently produced from 2-naphthol. The configuration of merocyanines 7a and 21a was unequivocally established by X-ray crystallography. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.

Photochromic behaviour of Bis[4-(N,N-dimethylamino)phenyl]-substituted 3H-naphtho[2,1-b]pyran and 2H-1-Benzopyran

The photochromic behaviour of 3,3-bis[4-(N,N-dimethylamino)phenyl]-3H-naphtho[2,1 -b]pyran (2) and 2,2-bis[4-(N,N-dimethylamino)phenyl]-2H-1 -benzopyran (3) has been studied by flash photolysis and compared to 3,3-diphenyl-3H-naphtho[2,1 -b]pyran (i) in order to delineate effects due to the N,N-dimethylamino groups.