| 摘要 |
NEW MATERIAL:The tolan derivative of formula I (R<1> is 1-10C alkyl; R<2> is 1-10C alkyl or alkyloxy; X is -CH2CH2- or single bond; A is H or F; when X is single bond, A is F). EXAMPLE:4-(trans-4-Propylcyclohexyl-1-ethyl)-4'-ethyltolan. USE:A liquid crystal substance having low viscosity and high compatibility with conventional liquid crystals at low temperature. The freedom of the selection of liquid crystal material can be improved. PREPARATION:The objective tolan derivative formula I can be produced e.g. by reacting a substituted benzene of formula II with a 4-substituted-phenylacetic acid chloride, subjecting the resultant ketone compound of formula III successively to reduction, dehydration and addition of bromine and finally reacting the product with potassium t-butoxide. |
