Related Experiment Video
Updated: Jan 23, 2026
Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives
Published on: January 19, 2016
Aminomethyl Transfer (Mannich) Reactions Between an O-Triethylsilylated Hemiaminal and Anilines, Rn C6 H5-n NH2
Anwar Jacintomoreno1, Hemant K Sharma1, Alejandro Metta-Magaña1
1Department of Chemistry, University of Texas at El Paso, El Paso, TX., 79968-0513, USA.
Abstract:
The reactions of the Mannich reagent Et3 SiOCH2 NMe2 (1) with a variety of anilines (mono-substituted RC6 H4 NH2 , R=H, 4-CN, 4-NO2 , 4-Ph, 4-Me, 4-MeO, 4-Me2 N; di-substituted R2 C6 H3 NH2 , R2 =3,5-(CH3 )2 , 3,5-(CF3 )2 ; tri-substituted R3 C6 H2 NH2 , R3 =3,5-Me2 -4-Br and a "super bulky" aniline (Ar*NH2 ) [Ar*=2,6-bis(diphenylmethyl)-4-tert-butylphenyl]) led to the formation of a range of products dependent upon the substituent. With electron-withdrawing substituents, previously unknown diamines, RC6 H4 NH(CH2 NMe2 ) [R=CN (2 a), NO2 (2 b)] and R2 C6 H3 NH(CH2 NMe2 ) [R2 =3,5-(CF3 )2 (2 c)] were formed. Further reaction of 2 a, b, c with 1 yielded the corresponding triamines RC6 H4 N(CH2 NMe2 )2 (R=CN (3 a), NO2 (3 b) and R2 C6 H3 N(CH2 NMe2 )2 , R2 =3,5-(CF3 )2 (3 c). The new polyamines were characterized by NMR spectroscopy, and for 2 a, 2 c, and 3 c, by single crystal XRD. In the case of electron-donating groups, R=4-OMe, 4-NMe2 , 4-Me, 3,5-Me2 , 3,5-Me2 -4-Br, and for R=4-Ph, the reactions with 1 immediately led to the formation of the related 1,3,5-triazines, R=4-MeO (5 a), 4-Me2 N (5 b), 4-Me (5 c), 3,5-Me2 (5 d), 3,5-Me2 -4-Br (5 e), 4-Ph (5 f), 4-Cl (5 g). The "super bulky" aniline rapidly produced a single product, namely the corresponding imine Ar*N=CH2 (4) which was also characterized by single crystal XRD. Imine 4 is both thermally and oxidatively stable. All reactions are very fast, thus based upon the presence of Si we are tempted to denote the reactions of 1 as examples of "Silick" chemistry.
Related Concept Videos
02:55Temperature Dependence on Reaction Rate
Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This premise is the basis for a theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates.
The collision theory is based on the postulates that (i) the reaction rate is proportional to the rate of reactant collisions, (ii) the reacting species collide in an orientation allowing contact between...
01:16Energy Transfer in Chemical Reactions
01:09Directing Effect of Substituents: meta-Directing Groups
01:23Aldehydes and Ketones with Amines: Imine Formation Mechanism
Imines are formed under mildly acidic conditions. A pH of 4.5 is ideal for the reaction.
If the pH is low or the solution is too acidic, the reaction slows down in the...
01:27Radical Substitution: Halogenation of Alkanes and Alkyl Substituents
In the initiation step of the reaction, the chlorine molecule undergoes homolytic cleavage in the presence of light or heat, forming two highly reactive chlorine radicals. Propagation occurs in two...
01:23Nomenclature of Aromatic Compounds with a Single Substituent