Patent GB-308229-A (GB)
Title: Improved process for the production of aldehyde sulphoxylates
IPC: C07C381/00
Filed: 1927-09-19
Abstract: 308,229. Johnson, J. Y., (I. G, Farbenindustrie Akt.-Ges.). Sept. 19, 1927. Aldehyde and ketone sulphoxylates are produced by reducing aldehyde or ketone bisulphites or aldehyde hydrosulphites by means of hydrogen or gases containing or supplying hydrogen, in presence of a hydrogenation catalyst under ordinary or raised pressure, but when formaldehyde bisulphite is to be reduced the reduction must be effected either with an activated catalyst or a pressure of at least 20 atmospheres. As catalysts the metals of the 8th group of the periodic system are suitable, especially nickel, cobalt, platinum and the like, and they may be used alone or on carriers in the presence or absence of other metals or activators such as copper, zinc, silver, tungsten, molybdenum. chromium, or oxides or sulphides of metals of various groups. Zinc sulphide or oxide, barium carbonate and beryllium oxide are mentioned as additions to nickel. The reduction is preferably effected in aqueous solution and salts such as sodium sulphate or calcium chloride or organic substances such as alcohol may be present; inert gases may also be introduced. Pressures up to 400 atmospheres are mentioned. When catalysts are used which have special activity in connection with other reductions, they are preferably first treated to reduce this activity, for example by admixing enfeebled or regenerated catalysts followed if necessary by heating, or by treating them with suitable gases such as carbon dioxide which may contain small amounts of steam or oxygen at high temperatures. In the examples sodium formaldehyde bisulphite is reduuced in aqueous or alcohol solution with hydrogen to presence of nickel on kieselguhr; or the nickel catalyst may be replaced by nickelchromium, or nickel-cobalt. When the catalyst contains about 2 per cent of sulphur, it may be reduced with hydrogen at 400-450‹ C. and can then be used again. Nickel-carbonate precipitated on kieselgubr and heated in hydrogen at 400-450‹ C. and then with carbon dioxide containing wate.r vapour at 250‹ C. is also used in the same manner. When a solution of zincformaldehyde bisulphite is employed, the product may be converted by zinc dust in any known way into the di-zinc formaldehyde sulphoxylate, which with caustic soda yields sodium formaldehyde sulphoxylate. Benzaldelyde, acetaldehyde and other aldehyde bisulphites may be reduced similarly. Another example describes the reduction of sodium benzaldehyde bisulphite by nickelkiselguhr catalyst activated with vanadium or by nickel-tungsten or nickel-vanadium tungsten; the product may be converted into the formaldehyde sulphoxylate by treatment with formaldehyde. In another example sodium m-tolylaldehyde bisulphite or a similar compound of a hydroxy-aldehyde such as salicyl-aldehyde in aqueous solution at p-H=7-7.5 is reduced by the aid of nickel on kieselguhr activated by vanadium. Other examples describe the reduction of sodium formaldehyde bisulphite, with catalysts containing nickel-tungsten-kieselguhr, nickel-tungsten-chromium, nickel-copper-tungsten or nickel-lead-vanadium; the reduction of sodium acetone bisulphite, with a nickel-vanadiumtungsten catalyst; and the reduction of sodium methyl-ethyl ketone bisulphite with a nickelchromium-tungsten-kieselguhr catalyst, the product yielding the formaldehyde sulphoxylate by treatment with formaldehyde. Details are given of the preparation of the various mixed catalysts.