Phenanthridine amino

Phenanthridine is known to undergo direct amination readily with hydride extrusion (the Chichibabin reaction) and further examples have been reported.22 More interesting is the preparation of 6-aminophenanthridine in high yield by the action of the sodium salt of N,N-dimethylhydrazine on phenanthridine in benzene. The adduct (224) (R = Me) loses dimethylamine on heating leaving the sodium salt of the 6-amino compound (225).318... 

Pictet-Hubert reaction. Phenanthridine cychzation by dehydrative ring closure of acyl-o-amino-biphenyls on heating with zinc chloride at 250-300C or with phosphorus oxychloride in boiling nitrobenzene. 

The general synthesis of phenanthridines, which are benzoisoquinolines, are patterned on isoquinolines. The lithiation route is similar to the one, where, for an isoquinoline synthesis, a p-phenylethyl amine (75) is the starting compound. The starting compound now is a 2-amino biphenyl (79). Interestingly, it is no more necessary to convert the primary amine to its dimethyl derivative. 

The amino group can then direct lithiation at 2 position and lead to a carbon substituent (like COOH or CHO) and lead to a phenanthridine synthesis. 

The synthesis of 6-amino-ll,12-dihydrobenzo[c]phenanthridine 133 and 6-amino-benzo[c]phenanthridine derivatives 134 was accomplished in a very straightforward approach by the condensation of 2-methylbenzonitrile 135 with aromatic aldehydes 136 resulting in the 6-amino-ll,12-dihydrobenzo[c]phenanthridine derivatives 133. Dehydrogenation of the dUiydro derivatives using DDQ yielded the 6-aminobenzo[c]phenanthridine derivatives 134 in Scheme 39 <0581052,05JMC2772, 05AG(1)635>. 

The condensation of the o-hydroxyarylidene-2-naphthylamines 400 (Ar = o-HOC6H4) with 1 gave the octahydro-xanthene 402 along with the benzo[fl]phenanthridines 390. It was assumed that the ortho-hydroxyl group caused a steric hindrance toward cyclization of the intermediate amino-diketone 401 as a result of which it underwent fission to give... 

The reaction between o-bromoaniline and 2-formylbenzeneboronic acid by the coupling procedure provides a new method for the preparation of phenanthridine. Applied to 2-amino-3-bromopyridines aza analogs are formed, as exemplified by the benzo[c][l,8]naphthyridine (232). Isomeric o-formylthiopheneboronic acids yield the corresponding thienylpyridines,... 

Perhaps the most efficient method for the preparation of the Af-amino-azonium salts is that using MSH.23 This rather new procedure has been shown to have many advantages over the other known methods (i) the procedure is very simple, (if) the reaction conditions are extremely mild, (iff) the scope is wide (i.e., it appears to parallel closely that of iV-oxidation by peracids24), and (iv) the yields are generally high. Recent applications of MSH (after 1976 for earlier applications, see Ref. 23) include pyridines,25-28 quinolines,29-31 naphthyridines,32 fused pyridines,32 phenanthridines,33,34... 

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