Preparation of Amino-, Hydrazino-, and Arylazocinnolines

The following routes to aminocinnolines have been covered already by primary synthesis (Chapter 1), by aminolysis of halogenocinnolines (Section 3.2), by 

The remaining approaches to aminocinnolines and arylazocinnolines are exemplifies here. 

3-Nitrocinnoline (15) gave 3-nitro-4-cimiolinamme (16) (substrate, H2NOH HCI, EtOH, KOH in EtOHi slowly, 2TC 50°C, 1 h -55%). =  

3-Phenylcinnoline (19) gave l-amino-3-phenylcinnoUn-l-ium mesitylene-sulfonate (19a) [substrate, CH2CI2, 2,4,6-Me3C6H2S(=0)20NH2 in CH2Cl2i dropwise, 0°C then 20°C, 10 min 65%).  

4-cinnolinecarbonitrile (20b) (Me2NH, MeOH, 20°C, 2h 60% steric hindrance to 4-aminolysis by the secondary amine was suggested as a reason for the changed regioselectivity). 

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