PROCESS FOR THE PROTECTION OF AMINO AND/OR IMINO GROUPS BY MEANS OF CARBONIC ACID ESTERS AND PROCESS FOR PREPARING NEW CARBONIC ACID ESTERS

摘要

Process for the protection of amino and/or imino groups in a cpd. comprises reaction of the cpd. containing one or more amino and/or imino group(s) with a carbonic acid ester (I): R1-O-CO-OR2 (I) (where R1 = alkyl (opt. substd. by halo, loweralkoxy or aryloxy) or lower aralkyl (opt. substd. by lower alkoxy, halo, nitro or cyano); R2 = benzotriazolyl (opt. halo. substd.), Y, Z = aryl (opt. substd. by one or more halo, lower alkoxy, nitro; cyano or lower haloalkyl) or an electron pulling group such as cyano, nitro, carbamoyl, esterified carboxy, lower alkanoyl, aroyl or desubstd. carbamoyl). Used in the synthesis of peptides, penicillins, cephalosporins and alkaloids. The cpds. (I) are novel provided that when R2= -N=CYZ and Y, Z = cyano, nitro, carbamoyl or esterified carboxy then R1 = arylalkyl having one or more substituents chosen from alkoxy, halo, nitro and cyano; and provided that when R1 = lower alkyl and R2 = -N=CYZ where Y = cyano and Z=aryl then the number of C atoms in the lower alkyl group R1 is 4 or 5. Some intermediates are novel.