Meta-substituted phenylalanine derivatives

L-,D-, and D,L-phenylalanine derivatives of formula I ##STR153## wherein n represents the number 0 or 1,

• R.sup.1 represents a basic group of formula (a), (b), (c), (d), or (e) ##STR154## R.sup.5 and R.sup.6 in formulae (a) and (b) represent hydrogen or an alkyl group of 1-2 carbon atoms,
• R.sup.2 represents
• (g) a group of formula ##STR155## wherein R.sup.7 represents hydrogen or a straight or branched lower alkyl group, R.sup.8 represents a straight or branched lower alkyl group, a 1- or 2-hydroxyethyl group, a methylmercaptoethyl group, an aminobutyl group, a guanidinopropyl group, a carboxy(lower)alkyl group, a carboxamido(lower)alkyl group, a phenyl(lower)alkyl group, the ring of which may be substituted with OH, halogen, lower alkyl or methoxy, a cyclohexyl or cyclohexylmethyl group, the ring of which may be substituted with OH, halogen, lower alkyl or methoxy, or an N-heteroaryl(lower)alkyl group wherein the heteroaryl moiety is imidazolyl or indolyl, and R.sup.9 represents a hydroxyl, straight or branched lower alkoxy or a benzyloxy group, the group (g) having a racemic, or D or L configuration, respectively,
• (h) A group of formula ##STR156## wherein m represents the number 1 or 2, R.sup.9 represents a hydroxyl, straight or branched lower alkoxy or a benzyloxy group, and wherein one of the methylene groups may be substituted with a hydroxyl, carboxyl, lower alkyl or aralkyl group, wherein a further phenyl or cyclohexyl ring may be condensed on the heterocycloaliphatic ring of formula (h) in position 2,3 or 3,4, related to the heteroatom, the group (h) having a racemic, or D or L configuration, respectively,
• (i) a group of formula ##STR157## wherein p=r=1, p=1 and r=2 or p=2 and r=1, R.sup.9 represents a hydroxyl, straight or branched lower alkoxy or a benzyloxy group, and wherein one of the methylene groups may be substituted with a hydroxyl, carboxyl, lower alkyl or aralkyl group, wherein a further phenyl or cyclohexyl ring may be condensed on the heterocycloaliphatic ring of formula (i) in position 2,3 or 3,4, related to the heteroatom,
• (k) a piperidyl group that is substituted with an alkyl group of 1-2 carbon atoms or hydroxyl group in one of the positions 2, 3, and 4, wherein a further phenyl or cyclohexyl ring may be condensed on the heterocycloaliphatic ring of formula (k) in position 2,3 or 3,4, related to the heteroatom,
• (l) a piperazyl group, which may be substituted in p position with a lower alkyl group or an alkoxycarbonyl group,
• (m) a group of formula ##STR158## wherein n' represents the numbers 1 to 6, R.sup.9 represents a hydroxyl, straight or branched lower alkoxy or a benzyloxy group, and R.sup.10 represents hydrogen or the methyl or cyclohexyl group,
• (n) a group of formula ##STR159## wherein R.sup.9 represents a hydroxyl, straight or branched lower alkoxy or a benzyloxy group, and,
• when n=0, R.sup.2 additionally represents (f) O-alkyl, O-cycloalkyl, or O-aralkyl, all having up to 8 carbon atoms, or OH,
• R.sup.3 represents hydrogen, an alkyl group of 1-2 carbon atoms, or a 1- or 2-hydroxyethyl group, and
• R.sup.4 represents phenyl, methylphenyl, .alpha.-naphthyl, .beta.-naphthyl, 5-(dimethylamino)-naphthyl, or quinolyl,
• wherein lower alkyl denotes alkyl of 1-4 carbon atoms,
• or pharmaceutically acceptable salts thereof with mineral or organic acids.