(+-)-4,4a,5,6-Tetrahydrobenzo(h)cinnolin-3(2H)-one 121866-05-5 5-24-03-00524 (Beilstein Handbook Reference) BRN 0881705 Benzo(h)cinnolin-3(2H)-one, 4,4a,5,6-tetrahydro-, (+-)-