Most of the compounds have physiologically active properties, and their biological properties are often attributed to the heteroatoms contained in their molecules, and most of these heteroatoms also appear in cyclic structures. A Journal, European Journal of Organic Chemistry called Selective Synthesis of 5,6-Dihydroindolo-[1,2-a]quinoxalines and 6,7-Dihydroindolo-[2,3-c]quinolines by Orthogonal Copper and Palladium Catalysis, Author is Zhang, Lei; Zhao, Fei; Zheng, Mingyue; Zhai, Yun; Wang, Jiang; Liu, Hong, which mentions a compound: 21778-81-4, SMILESS is O=CC(N1)=CC2=C1C=CC(OC)=C2, Molecular C10H9NO2, Quality Control of 5-Methoxy-1H-indole-2-carbaldehyde.
In combination with the Ugi four-component reaction, two important indole-fused heterocycles were prepared in two steps from readily accessible starting materials. From the same set of Ugi adducts 5, 5,6-dihydroindolo[1,2-a]quinoxalines were rapidly generated in excellent yields by a copper-catalyzed N-H arylation pathway, whereas 6,7-dihydroindolo[2,3-c]quinolones were obtained by palladium-catalyzed C-H arylations in good yields without the protection of the indole N1 moiety. Microwave heating was used to accelerate these intramol. C-N and C-C bond-forming reactions performed under controlled reaction conditions.
In addition to the literature in the link below, there is a lot of literature about this compound(5-Methoxy-1H-indole-2-carbaldehyde)Quality Control of 5-Methoxy-1H-indole-2-carbaldehyde, illustrating the importance and wide applicability of this compound(21778-81-4).
Reference:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem