Synthesis of 3-amino-5H-pyrimido[5,4-b]indol-4-one derivatives

Starting with ethyl 3-aminoindole-2-carboxylate, the synthesis of 3-amino-5H-pyrimido[5,4-b]indole-2,4-dione 5, 3-amino-5H-pyrimido[5,4-b]indol-4-one 10 and some related compounds is described. Preliminary results about the inhibition of platelet aggregation by these compounds is reported.