Influence of scale, stoichiometry and temperature on the synthesis of 2,8‐dihalo analogues of tröger's base from the corresponding anilines and paraformaldehyde

The yields of 2,8‐dihalo analogues of Tröger's base in the condensation between 4‐haloanilines and paraformaldehyde was found to be highly sensitive to the crucial reaction parameters of scale, stoichiometry and temperature. The reaction conditions were optimized allowing for the semi‐large scale synthesis of the 2,8‐diiodo‐ (2) and 2,8‐dibromo‐ (3) analogues, respectively.