1-Benzoyl-4a,6-dimethyl-3-phenyl-1,4,4a,6,7,7a-hexahydrofuro[3,2-c]pyridazin-6-yl methyl ether 1-Benzoyl-6-methoxy-4a,6-dimethyl-3-phenyl-1,4,4a,6,7,7a-hexahydrofuro[3,2-c]pyridazine AIDS-138175 AIDS138175 NSC644337