| 摘要 |
<p>Process for the manufacture of 2,5-bis- (benzoxazolyl)-thiophene compounds A process for the manufacture of 2,5-bis-(benzoxazolyl)-thiophenes of the formula , wherein R1, R2 and R3 represent hydrogen or certain non-chromophoric substituents and each of R4 and R5 independently represents a hydrogen atom or an alkyl group or together they represent a trimethylene or tetramethylene radical, by reacting a sulphide of the formula , with a dicarbonyl compound of the formula , or with a derivative thereof is described.</p> |
