NEW MATERIAL:Compounds of formula I (R1 is H or alkyl; R2 is H, alkyl, alkylphenyl or phenyl).

EXAMPLE: N-(6,7-dihydro-5H-benzo[6,7]cyclohepta[1,2-d]pyrimidin-4-yl) glycine.

USE: A platelet aggregation inhibitor.

PREPARATION: With 4-chloro-6,7-dihydro-5H-benzo[6,7]cyclohepta[1,2- d]pyrimidine of formula II, a corresponding amino acid is reacted in the pres ence of potassium carbonate in a polar solvent-water mixed solution to obtain the objective compound of formula I.