Home – Home – Jornals – Chemistry for Sustainable Development 2013 number 2

Acid catalytic condensation of 1,3-butadiene with para -quinones and the oxidation of resulting adducts can be performed in one technological stage in the presence of the aqueous solutions of Мо–V–P heteropolyacids (HPA) of general composition H_aP_zMo_yV_xO_b. These solutions possess bifunctional catalytic properties being strong Brønsted acids and rather strong reversibly acting oxidizers at the same time. The condensation of 1,4-naphthoquinone with 1,3-butadiene in HPA solutions leads to obtaining 9,10-anthraquinone (AQ) in mixture with tetrahydroanthraquinone (THA) and dihydroanthraquinone (DHA). In the course of a single-stage process without organic solvents, the HPA solution is reduced and poorly soluble mixture of THA, DHA and AQ (up to 50 %) precipitates almost quantitatively from the solution. The yield and purity of AQ can be improved substantially due to the use of organic solvents miscible with water (for example, acetone, 1,4-dioxane), as well as high-vanadium HPA of the composition H₁₅P₄Mo₁₈V₇O₈₉ and H₁₇P₃Mo₁₆V₁₀O₈₉. Optimization of the process allowed us to obtain the product containing not less than 90 % AQ. Results achieved in the work open outlooks for the development of low-waste process for the production of AQ from 1,3-butadiene and 1,4-naphthoquinone.