Method for preparation of an intermediate dye product

摘要

The present invention provides a novel method for the synthesis of an intermediate dye product having the following formula: wherein L is S, Te, or Se; R1 and R2 are either the same or different aryl or alkyl compounds; R3 is hydrogen or a short chain alkyl group; and Z is an anion. The process to formulate this intermediate compound entails reacting an R1-acetylene compound with an R2-acetylene compound (compounds A) into an enol ether compound with the R1 and/or R2 constituents (compound D) And from compound D, it forms into an intermediate dye compound having an L-based cyclic ring with the R1 and/or R2 constituents (compound F). With compound F the desired dye can be made with a greater overall yield for mass production.