Study On Synthesis And Process Of Unsymmetrical Benzodifuranones And Its Intermediates

Based on the analysis of bibliographer and evaluation of the principles of different processes, the novel process for synthesis of the new type of polyheterocyclic disperse dyestuff, unsymmetrical benzodifuranones and its intermediates was studied in the dissertation. The chemical structures of the product and the intermediates were identified and confirmed by IR, NMR, MS. Furthermore the methods of analysis were studied.A series of four 4-Alkoxybenzaldehyde compounds were synthesized with good yields from the reaction of 4-hydroxy benzaldehyde with alkyl bromide in the presence of acetone, potassium carbonate and potassium iodide .There were considerable work on the synthesis of mandelic acid and its derivatives. Among the large number of synthetic methods, the two routes were choosed and studied. The novel phase transfer catalysis process for preparation of mandelic acid compounds was studied and a series of seven mandelic acid componds were prepared. The optimum process parameters were selected by optimium experimental. The process that glyoxylic acid was reacted with an excess of phenol in aqueous solution was also studied, and a series of three componds were prepared.Hydroquinone was treated with mandelic acid or its derivatives in toluene or 80% H2SO4, as the result that the corresponding5-hydroxy-2-oxo-3-Ar-2,3-dihydrobenzofuran were prepared with the good yields in the presence of 80% H2SO4.The synthesis of the new type of polyheterocyclic disperse dyestuff ,unsymmetrical benzodifuranones, starting from mandelic acid or its derivatives and 5-hydroxy-2-oxo-3-Ar-2,3-dihydrobenzofuran was studied. The novel process was studied and the process parameters evaluated, in which acetic acid, 80% H2SO4; toluene, chlorobenzene, o-dichlorobenzene were used as the solution, concentrated sulphuric acid and toluene sulfonic acid as catalyst, ammonium persulphate and nitrobenzol as oxidant.It provides the theoretical basis and the feasible process parameters for the industrialization of novel disperse dyestuff of unsymmetrical benzodifuranones.