One-Pot Synthesis of Tetraazabis(tropocoronand)s and Podands from Benzo[<i>b</i>]cyclohept[<i>e</i>][1,4]oxazine and<i>α</i>,<i>ω</i>-Polymethylenediamines
The reactions of benzo[b]cyclohept[e][1,4]oxazine (9) with a 1.2 equivalent of α,ω-alkanediamines (2, n = 4—12) in ethanol at 80 °C afforded tropocoronands (5, n,n′ = 4,4—12,12) in a one-pot procedure and in high yields, while the reaction of 9 with an excess of 2 mainly gave tropopodands 12 (n,n′ = 4,4—6,6). The reactions of 9 with short-chain diamines 2 (n = 2,3) yielded bicyclic pyrazino or diazepino compounds as the main products. The reaction of 9 with ω-amino alcohol afforded the corresponding dihydroxy podands 23. The predicted pathways of the reaction of 9 with 2 were experimentally confirmed.