2H-pyrano[2,3-f]quinazoline derivatives with platelet antiaggregating and other activities

The synthesis of some N,N-disubstituted 4-amino-5,6-dihydro-3,8-diphenyl-2H-pyrano[2,3-f]quinazolin- 2-ones by the reaction of phenylchloroketene with a series of N,N-disubstituted (E)-6-aminomethylene-7,8-dihydro-2-phenylquinazolin-5(6H)-ones, followed by dehydrochlorination of the primary adducts with DBN, is described. The methylbenzylamino and diphenylamino derivatives showed platelet antiaggregating activity in vitro superior to that of acetylsalicylic acid. The 1-pyrrolidinyl derivative showed appreciable local anesthetic activity in mice, whereas the whole series of compounds exhibited weak antiinflammatory activity in rats.