... slightly 0022-262319411837-3956$04.50/0 0 1994 American Chemical Society Page 2. Tricyclic Quinoxalinediones Chart 1 Journal of Medicinal Chemistry, 1994, Vol. 37, No. 23 3957 la:R=H lb: R = CI 28: R = H 2b: R = CI 38: R = H 3b: R = CI 4 (L-689,560) 5 ...