Epoxy compounds usually have stronger nucleophilic ability, because the alkyl group on the oxygen atom makes the bond angle smaller, which makes the lone pair of electrons react more dissimilarly with the electron-deficient system. Compound: 2,3-Dihydrocinnolin-4(1H)-one hydrochloride, is researched, Molecular C8H9ClN2O, CAS is 137195-33-6, about 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.Reference of 2,3-Dihydrocinnolin-4(1H)-one hydrochloride.
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.
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》 also mentions many details about this compound(137195-33-6)Reference of 2,3-Dihydrocinnolin-4(1H)-one hydrochloride, you can pay attention to it, because details determine success or failure
Reference:
Cinnoline – Wikipedia,
Cinnoline – an overview | ScienceDirect Topics