METHOD FOR THE PREPARATION OF A MONOMER BASED ON THIOPHENE OF FORMULA (2,3-DIHYDROTHIENO 3,4-B1,4DIOXIN-2-YL)METHANOL AND THE MONOMER PREPARED IN THIS MANNER

摘要

The subject matter of the invention is a method for the preparation of a monomer based on thiophene of formula (2,3-dihydrothieno [3,4-b][1,4]dioxin-2-yl)methanol (VIII) and the monomer based on thiophene of formula (2,3-dihydrothieno [3,4-b][1,4]dioxin-2-yl)methanol (VIII) prepared in this manner, where the resulting monomer (VIII) contains less than 1 % wt. of a byproduct (IX) of formula 3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-3-ol and less than 0.1 % wt. of impurities of general formula (X, XI). This method produces the high purity monomer (VIII) and the whole process becomes very economically advantageous as the input raw materials or intermediates necessary for its synthesis are expensive and hard to get.