Snia Viscosa Societa Nazionale Industria Applicazioni Viscosa S.p.a.

Luigi Canavesi

Francesco Siclari

Mario De Gaetano

Pier P Rossi

A process for preparing .alpha.,.omega.-dicarboxylic acids of the formula OC--(CH.sub.2).sub.n --COOH in which n=6 to 10 is disclosed. The process consists of the catalytic oxidation of a compound of formula X--(CH.sub.2).sub.n --CHO wherein X is CHO or COOH and n is 6 to 10 by O.sub.2 pure or in mixture with inert gas, possibly under pressure, in at least one polar solvent, at a temperature comprised between 20.degree. and 90.degree. C. and in the presence of a catalyst. The catalyst is chosen from the group consisting of at least one cobalt (II) salt and one ferrous salt. The amount of the catalyst is .ltoreq.0.001 mol % calculated on the equivalents of the aldehyde groups in the starting compound.

Process for preparing .alpha.,.omega.-dicarboxylic acids

A process for recovering omega-amino-dodecanoic acid by separating the byoducts from the crude acid that comprises, in the sequence indicated (a) treating the crude acid in the presence of water with an acid (A) in such an amount as to obtain an acid (A)/amino acid molar ratio comprised of between 2:1 and 1:1, the amount of water being such as to dissolve at least part of the salt obtained and not to dissolve at least part of the by-products, (b) separating the phases into one containing most of the salt and another containing most of the by-products, (c) decomposing the salt by treatment with an organic or inorganic base (B) and isolating the amino acid in the free state.

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Solbiate Olona, Italy

Luigi Canavesi