Ravizza S.p.a.

Roberto Signorini

Alberto Verga

Francesco Mauri

Francesco Botre

New piperazino derivatives of formula ##STR1## in which R is a phenyl radical substituted with at least one sulphonamido group or a substituted nitrogenated heterocyclic ring, and A is CO, CH.sub.2, SO.sub.2, possessing inhibiting activity towards carbonic anhydrase. The new products are prepared from compounds of formula R-A-X in which X is OH, SH, halogen, OR'' or SR'' in which R'' is methyl, ethyl, phenyl, carbomethoxy, carboethoxy, and from a piperazino derivative of formula ##STR2## The R' group can also be introduced on termination of the reaction, by removing and substituting a protective group present at the nitrogen.

Pharmacologically active piperazino derivatives

A process for preparing 2(4-fluorophenyl).alpha.-methyl-5-benzoxazole acetic acid starting from 4-hydroxy-3-amino-phenylacetic acid, which is firstly reacted with 4-fluorobenzoyl chloride, and the product obtained is reacted with phosphoric acid; the 2(4-fluorophenyl)5-benzoxazole acetic acid obtained in this manner is esterified with ethyl alcohol, and the ester is treated with diethyloxalate; the ethyl 2(4-fluorophenyl)5-benzoxazole oxalacetate obtained is reacted with formaldehyde and potassium carbonate to obtain ethyl 2(4-fluorophenyl)5-benzoxazole acrylate, which is hydrolysed to obtain the corresponding acid, from which the 2(4-fluorophenyl).alpha.-methyl-5-benzoxazole acetic acid is obtained by hydrogenation.

Process for preparing 2(4-fluorophenyl)alpha-methyl-5-benzoxazole acetic

The application describes a process for preparing 2-phenyl derivatives of benzoxazolyl propionic acid of formula ##STR1## in which X is H, Cl, Br, F, or a linear or branched alkyl or 1 to 6 carbon atoms. The process starts from 3-nitro-4-hydroxyphenyl-.alpha.-methyl-acetonitrile which is hydrolysed in the presence of a strong acid, the 3-nitro-4-hydroxyphenyl-.alpha.-methylacetic acid thus obtained is hydrogenated in the presence of Pd on carbon, and the 3-amino-4-hydroxyphenyl-.alpha.-methylacetic acid deriving therefrom is first reacted with benzoyl chloride or with para-substituted benzoyl chloride in the presence of an alkaline base, and then with 85% phosphoric acid to complete the formation of the oxazolinic ring.

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Milan, Italy

Roberto Signorini