Indolyl-3-glyoxylic acid derivatives having antitumor action

N-Substituted indole-3-gloxylamides of the general formula 1 for use as antitumor agents,

• 158
• where the radicals R, R1, R2, R3, R4 and z have the following meaning:
• R=hydrogen, (C1-C6)-alkyl, where the alkyl group can be mono- or polysubstituted by the phenyl ring and this phenyl ring for its part can be mono- or polysubstituted by halogen, (C1-C6)-alkyl, (C3-C7)-cycloalkyl, by carboxyl groups, carboxyl groups esterified with C1-C6-alkanols, trifluoromethyl groups, hydroxyl groups, methoxy groups, ethoxy groups, benzyloxy groups and by a benzyl group which is mono- or polysubstituted in the phenyl moiety by (C1-C6)-alkyl groups, halogen atoms or trifluoromethyl groups,
• R is further the benzyloxycarbonyl group (Z group) and the tertiary-butoxycarbonyl radical (BOC radical), furthermore the acetyl group.
• R1 can be the phenyl ring, which is mono- or polysubstituted by (C1-C6)-alkyl, (C1-C6)-alkoxy, cyano, halogen, trifluoromethyl, hydroxyl, benzyloxy, nitro, amino, (C1-C6)-alkylamino, (C1-C6)-alkoxycarbonylamino and by the carboxyl group or by the carboxyl group esterified with C1-C6-alkanols, or can be a pyridine structure of the formula 2 and its N-oxide [sic]
• 159
• and its N-oxide, where the pyridine structure is alternatively bonded to the ring carbon atoms 2, 3 and 4 and can be substituted by the substituents R5 and R6. The radicals R5 and R6 can be identical or different and have the meaning (C1-C6)-alkyl and the meaning (C3-C7)-cycloalkyl, (C1-C6)-alkoxy, nitro, amino, hydroxyl, halogen and trifluoromethyl and further are the ethoxycarbonylamino radical and the group carboxyalkyloxy in which the alkyl group can have 1-4 C atoms.
• R1 can further be a 2- or 4-pyrimidinyl heterocycle, where the 2-pyrimidinyl ring can be mono- or polysubstituted by the methyl group, furthermore are [sic] the 2-, 3-, and 4- and 8-quinolyl structure substituted by (C1-C6)-alkyl, halogen, the nitro group, the amino group and the (C1-C6)-alkylamino radical, are [sic] a 2-, 3- and [sic] 4-quinolylmethyl group, where the ring carbons of the pyridylmethyl radical of the quinolyl group and of the quinolylmethyl radical can be substituted by (C1-C6)-alkyl, (C1-C6)-alkoxy, nitro, amino and (C1-C6)-alkoxycarbonylamino.
• R1, in the case in which R=hydrogen, the methyl or benzyl group and the benzyloxycarbonyl radical (Z radical), the tert-butoxycarbonyl radical (BOC radical) and the acetyl group, can furthermore be the following radicals:
• —CH2COOH;
• —CH(CH3)—COOH;
• —(CH3) 2—CH—(CH2) 2—CH—COO—;
• H3C—H2C—CH(CH3)—CH(COOH)—;
• HO—H2C—CH(COOH)—;
• phenyl-CH2—CH(COOH)—;
• (4-imidazolyl)-CH2—CH—(COOH)—;
• HN═C (NH2)—NH—(CH2)3—CH(COOH)—;
• H2N—(CH2)4—CH(COOH)—;
• H2N—CO—CH2—CH—(COOH)—;
• HOOC—(CH2)2—CH(COOH)—;
• R1, in the case in which R is hydrogen, the Z group, the BOC radical, the acetyl or the benzyl group, can furthermore be the acid radical of a natural or unnatural amino acid, e.g. the α-glycyl, the α-sarcosyl, the α-alanyl, the α-leucyl, the α-isoleucyl, the α-seryl, the α-phenylalanyl, the α-histidyl, the α-prolyl, the α-arginyl, the α-lysyl, the α-asparagyl and the α-glutamyl radical, where the amino groups of the respective amino acids can be present unprotected or can be protected. A possible protective group of the amino function is the carbobenzoxy radical (Z radical) and the tert-butoxycarbonyl radical (BOC radical) as well as the acetyl group. In the case of the asparagyl and glutamyl radical claimed for R1, the second, unbonded carboxyl group is present as a free carboxyl group or in the form of an ester with C1-C6-alkanols, e.g. as a methyl, ethyl or as a tert-butyl ester.
• Furthermore, R1 can be the allylamino-carbonyl-2-methylprop-1-yl group.
• R and R1 can further form, together with the nitrogen atom to which they are bonded, a piperazine ring of the formula 3 or a homopiperazine ring, provided R1 is an aminoalkylene group, in which
• 160
• R7 is an alkyl radical, is a phenyl ring which can be mono- or polysubstituted by (C1-C6)-alkyl, (C1-C6)-,alkoxy, halogen, the nitro group, the amino function and by the (C1-C6)-alkylamino group. R7 is furthermore the benzhydryl group and the bis-p-fluorobenzylhydryl group [sic].
• R2 can be hydrogen and the (C1-C6)-alkyl group, where the alkyl group is mono- or polysubstituted by halogen and phenyl, which for its part can be mono- or polysubstituted by halogen, (C1-C6)-alkyl, (C3-C7)-cycloalkyl, carboxyl groups, carboxyl groups esterified with C1-C6-alkanols, trifluoromethyl groups, hydroxyl groups, methoxy groups, ethoxy groups or benzyloxy groups. The (C1-C6)-alkyl group counting as R2 can further be substituted by the 2-quinolyl group and the 2-, 3- and 4-pyridyl structure, which can both in each case be mono- or polysubstituted by halogen, (C1-C4)-alkyl groups or (C1-C4)-alkoxy groups. R2 is further the aroyl radical, where the aryl moiety on which this radical is based is the phenyl ring, which can be mono- or polysubstituted by halogen, (C1-C6)-alkyl, (C3-C7)-cycloalkyl, carboxyl groups, carboxyl groups esterified with C1-C6-alkanols, trifluoromethyl groups, hydroxyl groups, methoxy groups, ethoxy groups or benzyloxy groups.
• R3 and R4 can be identical or different and are hydrogen, (C1-C6)-alkyl, (C3-C7)-cycloalkyl, (C1-C6)-alkanoyl, (C1-C6)-alkoxy, halogen and benzyloxy. R3 and R4 can furthermore be the nitro group, the amino group, the (C1-C4)-mono or dialkyl-substituted amino group, and the (C1-C6)-alkoxycarbonylamino function or (C1-C6)-alkoxycarbonylamino-(C1-C6)-alkyl function.
• Z is O and S.