Synthesis and structure elucidation of 5-aminomethinimino-3-methyl-4-isoxazolecarboxylic acid phenylamides and their immunological activity.

A series of 5-aminomethinimino-3-methyl-4-isoxazolecarboxylic acid phenylamides 4 has been prepared by condensation of 5-amino-3-methyl-4-isoxazolecarboxylic acid phenylamides 1 with trichloroacetic aldehyde. Alcoholysis of trichloro derivatives 2 gave 5-alkoxymethine derivatives 3 which, on reaction with an appropriate amine, formed the corresponding compounds 4. The compounds obtained were evaluated for their immunological activity. The properties of three compounds, described in this report, permitted inhibition of the immune response in all possible ways: diminishing both types of immune response (4d), humoral immune response (4a), or cellular immune response (4c). Preparation 4d is comparable in its effectiveness to CsA, so it may be potentially used as an agent for prolongation of the function of transplanted organs. Two other compounds may potentially be used in cases where only one type the immune response is required for combating pathogen invasion.