after subcutaneous injection application_number US 80139397 A description the three letter codes for the amino acid residues used herein are those stated in j biol chem 243 p 3558 1968 the expression u201c a codable amino acid u201d is intended to indicate an amino acid which can be coded for by the genetic code i e a triplet u201c codon u201d of nucleotides the compounds of the invention can be prepared by methods known per se thus the group u2014 co u2014 w u2014 cooh of formula i can be introduced into an insulin moiety via an activated ester or an activated amide e g an azolide of the diacid hooc w cooh the preparation of activated esters is described i a in ep 0 511 600 a2 kuraray co ltd and in wo 95 07931 novo nordisk a s the preparation of azolides is described i a in w foerst ed neure methoden der pr u00e4parativen organischen chemie band v p 53 93 verlag chemie weinheim 1967 the group u2014 co u2014 w u2014 cooh can be introduced into an insulin moiety in which the amino group of the n terminal amino groups of the a chain and the b chain is protected this is in analogy with the methods described in in wo 95 07931 in this case a deprotection step follows the introduction of the group u2014 co u2014 w u2014 cooh as illustrated in the appended examples 1 and 2 alternatively by selecting suitable reaction conditions as described e g in ep 0 712 862 a2 it is possible to introduce the group u2014 co u2014 w u2014 cooh selectively into the u03b5 amino group of a lys residue without resorting to protection of the n terminal.