| 摘要 |
NEW MATERIAL:A benzo(thio)xanthene compound of formula I, where X is O or S; R<1> is an alkyl, an alkoxy, benzyloxy, a trans-4-alkylcyclohexyl(alkyloxy), an alkylamino or a heterocyclic group; R<2> is a trans-4-alkylcyclohexylalkyl, a group of formula II (where R<3> is an alkylene; R<4> is benzyloxy or a trans-4- alkylcyclohexylalkyloxy), etc. USE:A dichroic dye used for a liquid crystal composition of guest-host effect type (having a high dichroic ratio and excellent solubility in a liquid crystal). PREPARATION:A compound of formula III is diazotized with sodium sulfite, etc. and then decomposed with copper sulfate, etc.
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