Kwapiszewski, Wincenty; Stanczak, Andrezej; Groszkowski, Stefan published the article 《Synthesis of new derivatives of 1,2,5-triazepino[1,2-a]cinnoline. II. Synthesis of haloacyl derivatives of 4-oxo-1,2,3,4-tetrahydrocinnoline》. Keywords: cinnolone tetrahydro haloacyl derivative.They researched the compound: 2,3-Dihydrocinnolin-4(1H)-one hydrochloride( cas:137195-33-6 ).COA of Formula: C8H9ClN2O. Aromatic heterocyclic compounds can be divided into two categories: single heterocyclic and fused heterocyclic. In addition, there is a lot of other information about this compound (cas:137195-33-6) here.
Stirring 1,2,3,4-tetrahydrocinnolin-4-one (I) with BrCH2COCl (II) in H2O at 0° gave 76% III (X = Br, R = R1 = R2 = H). III (X = Cl, R1 = R2 = H; R = Cl, Me, MeO; R = R1 = H, R2 = Cl, Me; R = H, R1 = R2 = MeO) were prepared analogously in 49-74% yields from the appropriately substituted I and ClCH2COCl (IV). When I and II were refluxed 10 h in C6H6, diacetylation occurred to give 67% V (X = Br, R1 = R2 = H). V (X = Cl, R1 = R2 = MeO; R1 = H, R2 = Cl, Me) were prepared analogously. V (X = Cl, R1 = R2 = H) was obtained from the corresponding III and IV in the presence of Et3N. Refluxing I 10 h with ClCH2CH2COCl in C6H6 gave 54% VI, which was also obtained as a byproduct when a similar reaction was carried out at 0° in CHCl3; the main product (60% yield) was 2-(3-chloropropionyl)-1,2,3,4-tetrahydrocinnolin-4-one.
There is still a lot of research devoted to this compound(SMILES：O=C1CNNC2=C1C=CC=C2.[H]Cl)COA of Formula: C8H9ClN2O, and with the development of science, more effects of this compound(137195-33-6) can be discovered.
Reference:
Cinnoline – Wikipedia,
Cinnoline – an overview | ScienceDirect Topics