Pyridine, 3-amino 2-BENZYLAMIN

N-Silylated peptide esters are acylated by the acid chloride of N-Cbo-glycine to N-acylated peptide bonds [11]. Likewise, acid chlorides, prepared by treatment of carboxylic acids with oxalyl chloride, react with HMDS 2 at 24°C in CH2CI2 to give Me3SiCl 14 and primary amides in 50-92% yield [12]. Free amino acids such as L-phenylalanine or /5-alanine are silylated by Me2SiCl2 48 in pyridine to 0,N-protected and activated cyclic intermediates, which are not isolated but reacted in situ with three equivalents of benzylamine to give, after 16 h and subsequent chro-... 

The buffers for cations are usually composed of an absorbing co-ion such as imidazole (Figure 10), phenylethylamine, benzylamine, 4-methylbenzylamine, nicotinamide, or amino-pyridine (Figure 11). Beckers and Bocek recommends histamine, His, or imidazole as they... 

Reactions of 5f/-2-methyl-l,2,4-triazepino[2,3- ]benzimidazol-4-one 71, prepared by reaction of 1,2-diaminobenz-imidazole 72 with acetoacetic ester 73, with different reagents was described, in the search of new heterocycles with biological activity <2002CHE598>. When lactam 71 was treated with aromatic aldehydes in boiling 1-BuOH with addition of piperidine 74, 577-3-arylidene-2-methyl-l,2,4-triazepino[2,3- ]benzimidazol-4-ones 75a-c were obtained (Scheme 7). Coupling lactam 71 with phenyldiazonium chloride 76 in dioxane afforded the 3-phenylazo-substituted tricycle 77. When 71 was treated with phosphorus pentasulfide 78 in boiling dioxane or pyridine, its thio analog 79 was obtained. The reaction proceeded most efficiently when lactam 71 was refluxed with twofold excess of 78 in dry dioxane. These thiones 79 react with ammonia and amines by nucleophilic substitution. When 79 was refluxed with ammonia, benzylamine, piperidine, or morpholine, the 4-amino-substituted tricycles 80a-d were obtained. All the described compounds were identified by NMR, mass spectrometry, and IR spectroscopy. 

For 2-benzylaminopyridine the methods of significance in the literature are condensation of 2-pyridinesulfonic acid and benzylamine,4 condensation of the alkali metal salts of 2-amino-pyridine with benzyl chloride,6 reductive alkylation of 2-amino-pyridine in the presence of benzaldehyde and formic acid,2 oxidation of N-benzyl-N-pyridylaminoacetonitrile or N-benzyl-N-pyridylaminoacetaldoxine,6 and the method described here modified by use of an inert solvent.7... 

According to mechanistic considerations of Scheme 8, benzylamine arylation should also be feasible. The palladation of benzylamines in strong acid might be retarded due to protonation of the directing amino group. Employing a limited amount of trifluoroacetic acid solvent allowed efficient benzylamine arylation [63], Specifically, the benzylamine arylation reactions are the fastest if about five equivalents of trifluoroacetic acid solvent are used. A number of benzylamines and A-methy lbenzy I am i n e s were shown to be reactive under these conditions (Scheme 16). The reactions proceed well with both electron-rich and moderately electron-poor benzylamines. For unsubstituted or 4-substituted benzylamines, 2,6-diarylation is observed. Benzylamines substituted at the 3-position are monoarylated. As in the case of pyridine and anilide arylation, bromine is tolerated on the substrate, and even iodide is compatible with the reaction conditions, although the yield is reduced. The products are acylated after the reaction to facilitate isolation. 

Related Reagents. Bis(bicyclo[2.2.1]hepta-2,5-diene)rho-dium Perchlorate [l,4-Bis(diphenylphosphino)butane](norbora-diene)rhodium Tetrafluroborate Catecholborane (1,5-Cycloocta-diene)[ 1,4-Bis(diphenylphosphino)butane]iridium(I) Tetrafluoro-borate (1,5-Cyclooctadiene)(tricyclohexylphosphine)(pyridine) iridium(I) Hexafluorophosphate Octacarbonyldicobalt Palladium (II) Chloride Tetrakis(triphenylphosphine)palladium(0) 2-Amino-3-picoline Benzylamine. 

The 2-formyl-pyridine-based PPEI (79), a bidentate, and the 2,6-diformyl-P3rridine-based BDFEPI (80), a potentially terdentate, ligands bear a-methyl-benzylamine and amino-1,2-diphenylethane chiral moieties, respectively... 

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