Antigen derivatives and processes for their preparation

Claim 1

A compound of the formula I ##STR10## in which X is a carbonyl group, R 1 , R 4 and R 6 independently of one another represent hydrogen tri-lower alkyl-silyl, alkyl having from 1 to 18 carbon atoms, benzyl which is unsubstituted or substituted in the aromatic nucleus by lower alkyl, hydroxyl, lower alkoxy, lower alkylenedioxy, mercapto, lower alkylmercapto, trifluoromethyl and/or halogen, or represent alkanoyl having from 2 to 18 carbon atoms, benzoyl or naphthoyl which are unsubstituted or substituted by halogen, lower alkyl, lower alkoxy, trifluoromethyl, hydroxyl or lower alkanoyloxy, or represent an acyl radical of a lower alkanesulfonic acid or of phenylsulfonic acid, which is unsubstituted or substituted by lower alkyl or halogen, or represent carbamoyl, lower alkyl-carbamoyl or phenyl-carbamoyl, R 2 represents alkyl having 1 to 18 carbon atoms which is unsubstituted or substituted by hydroxy, lower alkoxy, lower alkanoyloxy, halogen, mercapto, lower alkylmercapto, lower alkanoylmercapto, carboxy, lower alkoxycarbonyl and/or carbamoyl, or represents phenyl which is unsubstituted or substituted by lower alkyl, hydroxy, lower alkoxy, lower alkanoyl, lower alkylenedioxy, halogen and/or trifluoromethyl, R 3 represent hydrogen or lower alkyl, at least one of the radicals R 7 , R 9 and R 13 represents lower alkyl, and the others represent hydrogen, R 8 is hydrogen, lower alkyl which is unsubstituted or substituted by hydroxy, lower alkoxy, lower alkanoyloxy, mercapto, lower alkylmercapto, lower alkanoylmercapto, amino, lower alkanoylamino, carbamoylamino or cycloalkyl having 5 or 6 carbon atoms, or represents cycloalkyl-lower alkyl having 5 or 6 carbon atoms, in the cyclic moiety, phenyl or phenyl-lower alkyl, in which the phenyl radicals are unsubstituted or substituted as defined above, or heterocyclyl or heterocyclyl-lower alkyl wherein the heterocyclyl radicals are 5- or 6-membered, contain one or two nitrogen atoms in the ring and may or may not contain a fused phenyl radical, R 7 and R 8 together can also represent alkylene having 3 or 4 carbon atoms, R 10 , R 11 and R 12 independently of one another represent carboxyl, lower alkoxycarbonyl or carbamoyl which is unsubstituted or mono- or disubstituted at the nitrogen atom by unsubstituted, or carboxy- or carbamoyl-substituted, lower alkyl or by phenyl, benzyl, tetramethylene or pentamethylene or R 11 can also be hydrogen, or a salt of such a compound having a salt-forming group.