Azepine 4- amine-benzo

In contrast to 6-azidobenzo[/)]thiophene, which yields only benzo[i]thiophen-6-amine (9 %) and JVh,Ar(1-diethylbenzo[/)]thiopheiie-6,7-diamine (25 % bp 175-177 C/0.7 Torr), 6-azido-2,3-dibromobcnzojhjthiophene (1 a, R = R2 = Br) on irradiation in diethylamine in the presence of pyrene, a triplet nitrene quenching agent, yields a mixture of 2,3-dibromo-./V6,./V6-diethyl-benzo[5]thiophene-6,7-diamine (2a, R1 = R2 = Br 13%) and the 8W-thieno[2,3-r]azepine 3a.14<1 Likewise, methyl 6-azidobenzo[6]thiophene-2-carboxylate (lb, R1 = C02Me R2 = H) yields the thienoazepine ester 3b.147... 

Contrary to the stable azepines and diazepines, benzo[ 7]benzofuro[2,3-/][l,4]-oxazepine 272 undergoes ring cleavage under reductive conditions in the acetic acid/acetic anhydride to afford open chain acetoxy amine 273 (Scheme 58, Section 3.2.2 (2001JHC383)). 

Hexamethyleneimine and its benzo derivatives are typical secondary amines and undergo electrophilic substitution at nitrogen, e.g. alkylation and acylation, under standard conditions. Most form stable hydrochlorides and simple derivatives such as picrates (B-67MI51600). Table 4 contains pjRTa values of some azepines. 

A benzolog of 1 //-naphtho[o/]azepine-2-one 506 is obtained by cy-clization of l-(2 -amino)phenyl-8-methoxycarbony [naphthalene 505 (71AJC835). The reduction of azepinone 506 to azepine 507, followed by dehydrogenation with dichlorodicyanobenzoquinone (DDBQ) leads to benzo[/]naphtho[crf]azepine 508. The latter compound easily adds water, alcohol, or amines to a C=N bond, resulting in adducts 509, whereas treatment with perchloric acid gives rise to perchlorate 510 (71AJC835). 

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