Synthese von substituierten 2-(Ethoxycarbonyl-formyl-methylen)-2H-benzopyranen und ihre Überführung in Polymethinderivate
摘要:
3-Chloro-2-ethoxycarbonyl crotonic aldehyde C reacts with several 2-hydroxybenzene carbaldehydes and 2-hydroxy-naphthalene-1-carbaldehyde, respectively, to give 2-(ethoxycarbonyl-formyl-methplene)-2H-benzopyrans la-h under mild conditions. With exception of Ic and Id these compounds are mixtures of E-Z isomers. la-h easily undergo reactions, e.g. with aniline and derivatives to give 2a-e, with various CH-acidic compounds to give 3a-h and with 2-alkyl-4,6-diphenyl pyrylium salts to give 4a-e. In the presence of alcoholic hydrochloric acid, compounds 1 are converted into symmetrical 2,2'-benzopyrylotrimethine salts 5a-e which exhibit longwave absorptions from 640-705 nm. These polymethine dyes with ester groups in the methine chain exhibit a remarkable thermal stability.
Synthese von substituierten 2-(Ethoxycarbonyl-formyl-methylen)-2H-benzopyranen und ihre Überführung in Polymethinderivate
摘要:
3-Chloro-2-ethoxycarbonyl crotonic aldehyde C reacts with several 2-hydroxybenzene carbaldehydes and 2-hydroxy-naphthalene-1-carbaldehyde, respectively, to give 2-(ethoxycarbonyl-formyl-methplene)-2H-benzopyrans la-h under mild conditions. With exception of Ic and Id these compounds are mixtures of E-Z isomers. la-h easily undergo reactions, e.g. with aniline and derivatives to give 2a-e, with various CH-acidic compounds to give 3a-h and with 2-alkyl-4,6-diphenyl pyrylium salts to give 4a-e. In the presence of alcoholic hydrochloric acid, compounds 1 are converted into symmetrical 2,2'-benzopyrylotrimethine salts 5a-e which exhibit longwave absorptions from 640-705 nm. These polymethine dyes with ester groups in the methine chain exhibit a remarkable thermal stability.
3-Chloro-2-ethoxycarbonyl crotonic aldehyde C reacts with several 2-hydroxybenzene carbaldehydes and 2-hydroxy-naphthalene-1-carbaldehyde, respectively, to give 2-(ethoxycarbonyl-formyl-methplene)-2H-benzopyrans la-h under mild conditions. With exception of Ic and Id these compounds are mixtures of E-Z isomers. la-h easily undergo reactions, e.g. with aniline and derivatives to give 2a-e, with various CH-acidic compounds to give 3a-h and with 2-alkyl-4,6-diphenyl pyrylium salts to give 4a-e. In the presence of alcoholic hydrochloric acid, compounds 1 are converted into symmetrical 2,2'-benzopyrylotrimethine salts 5a-e which exhibit longwave absorptions from 640-705 nm. These polymethine dyes with ester groups in the methine chain exhibit a remarkable thermal stability.