Methanol is a potential hydrogen source and C1 synthon, which finds interesting applications in both chemical synthesis and energy technologies. The effective utilization of this simple alcohol in organic synthesis is of central importance and attracts scientific interest. Herein, we report a clean and cost‐competitive method with the use of methanol as both C1 synthon and H2 source for selective N‐methylation of amines by employing relatively cheap RuCl3.xH2O as a ligand‐free catalyst. This readily available catalyst tolerates various amines comprising electron‐deficient and electron‐donating groups and allows them to transform into corresponding N‐methylated products in moderate to excellent yields. In addition, few marketed pharmaceutical agents (e. g., venlafaxine and imipramine) were also successfully synthesized via late‐stage functionalization from readily available feedstock chemicals, highlighting synthetic value of this advanced N‐methylation reaction. Using this platform, we also attempted tandem reactions with selected nitroarenes to convert them into corresponding N‐methylated amines using MeOH under H2‐free conditions including transfer hydrogenation of nitroarenes‐to‐anilines and prepared drug molecules (e. g., benzocaine and butamben) as well as key pharmaceutical intermediates. We further enable one‐shot selective and green syntheses of 1‐methylbenzimidazole using ortho‐phenylenediamine (OPDA) and methanol as coupling partners.

Kinetics of oxidation of acidic amino acids (glutamic acid (Glu) and aspartic acid (Asp)) by sodium N-bromobenzenesulphonamide (bromamine-B or BAB) has been carried out in aqueous HClO 4 medium at 30°C. The rate shows firstorder dependence each on [BAB] o and [amino acid] o and inverse first-order on [H + ]. At [H + ] > 0⋅60 mol dm-3 , the rate levelled off indicating zero-order dependence on [H + ] and, under these conditions, the rate has fractional order dependence on [amino acid]. Succinic and malonic acids have been identified as the products. Variation of ionic strength and addition of the reaction product benzenesulphonamide or halide ions had no significant effect on the reaction rate. There is positive effect of dielectric constant of the solvent. Proton inventory studies in H 2 O-D 2 O mixtures showed the involvement of a single exchangeable proton of the OHion in the transition state. Kinetic investigations have revealed that the order of reactivity is Asp > Glu. The rate laws proposed and derived in agreement with experimental results are discussed.

. Addition of the reaction product (p-toluenesulfonamide or benzenesulfonamide) had no significant effect on the reaction rate. Variation of ionic strength and addition of halide ions have no influence on the rate. There is a negative effect of dielectric constant of the solvent. Studies of solvent isotope effects using D 2 O showed a retardation of rate in the heavier medium. The reaction was studied at different temperatures, and activation parameters have been computed from the Arrhenius and Eyring plots. Isonicotinic acid was identified as the oxidation product by GC-MS. A two-pathway mechanism is proposed in which RNHX and the anion RNX Ϫ interact with the substrate in the rate-limiting steps. The mechanism proposed and the derived rate laws are consistent with the observed kinetics. The rate of oxidation of INH increases in the order: BAT Ͼ BAB Ͼ CAT Ͼ CAB. This effect is mainly due to electronic factors.

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