Systems with Fifteen Conjugated Atoms

Reaction of the salts 349 (Section III,D,4) with a number of primary amines and hydrazines gives the 11-amino bromides (350). Treatment of two of these salts [350 R = R = H, R = Me.NiCiU)., and NH CSNH] with base gives the free betaines [346 R = R2 = H, R = Me2N(CH2)3 and NH2CSNH] as stable solids. 

In the presence of dimethyl malonate and aqueous sodium hydroxide, the 

Compounds of this type are readily prepared from the pyrido[l,2-6]-cinnolinium-ll-olates (338) (Section III,D,1) by reaction with phosphorus pentasulhde. Alkylation with ethyl bromoacetate gives the 11-ethoxycar-boxylmethylthio salts (349) which are useful intermediates for preparing other derivatives (Sections III,D,2 and 3). Hydrolysis of 349 regenerates the betaines 348. 

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