2.5- Diaryl-substituted 1,3,4-oxadiazines

Numerous l,3,4-oxadiazin-5(6//)-ones can be prepared by this type of cyclization. Examples arc 2-(l-ethyl-l-hydroxypropyl)-4-phenyl-4//-l,3,4-oxadiazin-5(6//)-one (6),40 4-phenyl-2-(4-tolyl)-4//-1,3,4-oxadiazin-5(6//)-one (7) (which is claimed to be useful as a miticide and nerna-tocide),41 4-cyanomethyl-, 4-(2-cyanoethyl)-, 4-(3-cyanopropyl)- and 4-(4-cyanobutyl)-6-methyl-2-phenyl-4//-l,3,4-oxadiazin-5(6//)-onc (8, n = 1, 2, 3 and 4, respectively) (which inhibit monoamine oxidase Type A and Type B),42 various 2,4-diaryl-4//-l,3,4-oxadiazin-5(6//)-ones 9 (which possess acaricidal activity),43 cardiotonic 2-aryl derivatives 10,44 and some heteroaryl-substituted compounds, such as 2-[4-(imida/.ol-l-yl)phenyl]-4f/-l,3,4-oxadiazin-5(6//)-one (11) (which is claimed to be cardiotonic and antihypertensive)45 and 2-(2-methylimidazo[l,2-a]pyridin-3-yl)-4//-l,3,4-oxadiazin-5(6//)-one (12) (which inhibits blood platelet aggrega-... 

---