Abstract The synthesis of 5, 10-dideazaaminopterin by two independent routes is described. Condensation of the piperidine enamine of 4-p-carbomethoxyphenylbutyraldehyde (4) with ethoxymethylenemalononitrile followed by treatment of the resultant arylethylenaminomalononitrile (5) with methanolic ammonia produced 2-amino-3-cyano-5-p- carbomethoxyphenethylpyridine (6). Cyclization of the aminocyanopyridine with ...