Preventing metal corrosion during prodn. of acyl-chloride(s) - using metals with electro-negativity of above 1.2

摘要

Inhibition of corrosion of metallic workpieces in the prodn. of aliphatic, aromatic or araliphatic carboxylic acid chlorides from phosgene and corresp. carboxylic acids (anhydrides) is new. The reactions take place in the presence of dialkylated carboxylic acid amides and/or tri-substd. phosphanoxides and/or sulphides as phosgenating catalysts. - At the end of phosgenation, metal (cpds) having an electronegativity of at least 1.2 are added to the reaction mixt. in at least equi-molar amts w.r.t. the catalyst at 80-180deg.C, as corrosion inhibitors (claimed). (6pp Dwg.no.0/0)