5.8- Dihydro-1-naphthylamine

Quinazolines 51 have been prepared by the condensation of A-aryl carbamates with hexamine, followed by aromatisation of the dihydro intermediate. A variety of mono- and di-substituted anilides were used, mefa-substituted starting materials giving 7-substituted quinazolines <06T12351>. Benzoquinazolines were also prepared similarly from naphthylamine carbamates <06OL255>. 

The condensation of 2-naphthylamine hydrochloride, cyanoguanidine and acetone yields, in addition to the expected dihydro-s-triazine, l-(2-naphthyl)biguanide and 3-guanidino-l-methylbenzo[f]quinazoline (554). 

The attempted intramolecular cyclization of the substituted naphthylamines XVI failed and led only to an intermolecular coupling [92]. 4-Substituted diphenylamines form in a remarkable cyclodimerization 5,10-dihydro-5,10-diphenylphenazines [Eq. (10)] [84], One requirement is that all para positions must be substituted by groups that are not eliminated and not strongly electron withdrawing. Yields are increased by electrolyzing at low current densities. Di-(2-naphthyl)amine undergoes the same reaction anodically, but... 

Oxosanguinarine (35) has been isolated from the mother liquor after the crystalization of 33 and identified by m.p. and spectral data [119], The formation of oxo- and dihydro sanguinarine was proved in an independent experiment when the composition of the alkaline reaction mixture was monitored using HPLC. As the compounds 35 (a lactam) and 36 (a substituted naphthylamine) are virtually non-basic species they were readily... 

Naphthalene, 21, 34, 44, 45 2-acetamido-, 60 dihydro-, 45 tetrahydro-, 45 Naphthoic acid, 51 a-Naphthol, 8, 44 /3-Naphthol, 8, 44 Naphthol, 6-acetamido-2-, 60 2-amino-1-, 60 Naphthoresorcinol, 5-8, 29 Naphthylamines, 60 Neomenthol, 73 Nicotinic acid, 63... 

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