In general, if the atoms that make up the ring contain heteroatoms, such rings become heterocycles, and organic compounds containing heterocycles are called heterocyclic compounds. An article called 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, published in 1992, which mentions a compound: 137195-33-6, Name is 2,3-Dihydrocinnolin-4(1H)-one hydrochloride, Molecular C8H9ClN2O, Category: cinnoline.
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.
This compound(2,3-Dihydrocinnolin-4(1H)-one hydrochloride)Category: cinnoline was discussed at the molecular level, the effects of temperature and reaction time on the properties of the compound were discussed, and the optimum reaction conditions were selected.
Reference:
Cinnoline – Wikipedia,
Cinnoline – an overview | ScienceDirect Topics