Abstract: Process for the production of 2-chloroacetoacetic acid amides. Diketene is converted at a temperature of +30.degree. to -40.degree. C. with the help of hydrogen chloride into acetoacetic acid chloride. Chlorine is introduced into the mixture at a temperature of +30.degree. to -40.degree. C., whereby 2-chloroacetoacetic acid chloride is formed. The latter is converted into the corresponding amide at a temperature of +50.degree. to -40.degree. C. by reaction with a N-compound having the formula: ##STR1## wherein (i) R=R'=H, or(ii) R=R'=alkyl, substituted alkyl, aryl, substituted aryl, alkyl aryl, substituted alkyl aryl, alkoxy aryl, substituted alkoxy aryl, alkoxy alkyl or substituted alkoxy alky, or(iii) R=H, and R'=alkyl, substituted alkyl, aryl, substituted aryl, alkyl aryl, substituted alkyl aryl, alkoxy aryl, substituted alkoxy aryl, alkoxy alkyl or substituted alkoxy alkyl.

Abstract: Process for the production of tetronic acid from 4-haloacetoacetic ester which begins by converting a 4-haloacetoacetic ester into the corresponding 4-benzyloxyacetoacetic ester. The 4-benzyl ester is then hydrogenolyzed into an intermediate product. The 4-hydroxyacetoacetic ester is converted by treatment with acid into tetronic acid. The 4-hydroxyacetoacetic ester can be isolated before conversion. The 4-benzyloxyacetoacetic ester can be produced by conversion of the 4-haloacetoacetic ester with a metal salt of benzyl alcohol. The hydrogenolysis can be carried out in the presence of an acid, whereby the 4-hydroxyacetoacetic ester forming in situ is rearranged directly into tetronic acid. The hydrogenolysis can be carried out under pressure in the presence of a hydrogenation catalyst.

Abstract: Process for the production of tetronic acid from 4-haloacetoacetic ester. The 4-haloacetoacetic ester is transformed into the corresponding 4-tertiary-butoxyacetoacetic ester and the latter is converted by cyclizing ether cleavage into tetronic acid. Preferably the cyclizing ether cleavage is carried out thermolytically at a temperature above 100.degree. C. or is carried out by treatment with an acid at a temperature of 0.degree. to 30.degree. C. Tertiary-butoxyacetoacetic acid ethyl ester is a new compound.