Dimethyl 6H,12H-5,11-methanodibenzo[b,f][1,5]diazocine-2,8-dicarboxylate

Abstract

In the mol­ecule of the title compound, C19H18N2O4, the 2,8‐dimethyl ester analogue of Tröger's base, the diazo­cine bridge imparts a twist such that the two aryl rings are offset with respect to one another. The dihedral angle between the two benzene rings is 96.51 (5)°.

Synthesis of Symmetric Diester‐Functionalised Tröger's Base Analogues

“…The dihedral angle has been found to vary between 82° [ 30] and 110° [ 31] for simple dibenzo Tröger's base analogues and is dependant upon the nature of the substituents. In the present case, the dihedral angle of 12 was measured as 88.6°, smaller than the values of 96.5°, 98.2°and 93.2°previously reported for 2, [22] 6 [32] and 13, [29] respectively.…”

“…In our hands the preparation of the methyl ester 2 on a small scale (1 g) was reasonably successful, and a yield of 23 % was obtained when employing paraformaldehyde as the formaldehyde equivalent and TFA as the acid source and as a solvent. [22] However, when the reaction was performed on a multigram scale, work-up and purification became problematic due to the poor solubility of the desired material in organic solvents, and the yields were typically 10-15 %.…”

“…Only three estersubstituted anilines have been converted into Tröger's base compounds, and all bear the esters at the 2,8-positions. [9,[20][21][22][23] One of these reactions involved the synthesis of a highly substituted Tröger's base (dimethyl 4,10dichloro-1,7-dimethoxy-2,8-dicarboxylate) in 16 % yield via a stepwise procedure that employed harsh reaction conditions (DMSO,(185)(186)(187)(188)(189)(190)(191)(192)(193)(194)(195)9 h). [20] A 2,8-diethyl ester Tröger's base analogue was prepared on a small scale (Ͻ 200 mg) in 37 % yield from the reaction of ethyl 4-aminobenzoate with DMSO and hydrogen chloride.…”

Diethyl 4,10-dibromo-5,11-methano-6H,12H-dibenzo[b,f][1,5]diazocine-2,8-dicarboxylate

“…The incorporation of bromo groups in the 4-and 10-positions of a 2,8-diester framework results in a less than 2 increase in the dihedral angle [cf. 98.24 (4) in the present case versus 96.51 (5) for the simple 2,8-dimethyl ester analogue of Trö ger's base (Faroughi et al, 2006a)]. This is in contrast with the variations observed between the structures of 2,8-dibromo and 2,4,8,10-tetrabromo Trö ger's bases, where the difference in dihedral angles has been measured at 14 [cf.…”

One‐Step Synthesis of Tröger's Base Hybrids Containing at Least One Halogen Atom

“…The work of Wärnmark's group on the preparation of dihalogenated compounds [23] was the first step to dismantling this misconception. There have been subsequent reports of tetrahalo, [24][25][26] and octafluoro analogues, [27] and diester-, [22,26,[28][29][30][31] dinitro- [26,[32][33][34][35] and even tetranitro-substituted [36] Tröger's base analogues have now been prepared. The second belief was that a substituent must be present in the p-position to prevent polymer formation, as a result of an additional condensation with formaldehyde at the activated site para to the aniline nitrogen atom.…”