2003 年 19 巻 6 号 p. 973-974
The structure of the Diels-Alder cycloadduct formed from 2-(1,2,3-1H-benzotriazol-1-yl)-2-(p-tolyl)-2H-isoindole and dimethyl acetylenedicarboxylate was proved as 11-aza-1-(1,2,3-1H-benzotriazol-1-yl)-11-(4-methylphenyl)-tricyclo-[5.2.1.02,7]undeca-2,4,6,9-tetraene-9,10-dioic acid dimethyl ester. The benzotriazole moiety was located as its 1-yl form, analogous to previous reports. The benzotriazole and the benzene (of tricyclo framework) planes were twisted with an angle of 115.83°. Intramolecular close contacts between benzotriazole and ester are characteristic [N(3)…C(26), 2.754(3)Å; N(3)…H(22), 3.26(4)Å]. The shortest contact of N(3)…H(22) accounting for the rotation of the methyl group is estimated to be 3.10 Å, which might be reasonable as C-H…N-type hydrogen bonding.