2- Pentanone reductive amination

The yields of primary amines over platinum oxide were improved in the presence of an excess molar equivalent of ammonium chloride in low pressure reductive alkylation of ammonia with ketones in methanol saturated with ammonia.10 With acetophenone and 4-methyl-2-pentanone, the yields of primary amine increased from 37 and 49% in the absence of ammonium chloride to 69 and 57-65%, respectively, in the presence of ammonium chloride. Moller obtained a much higher yield (>90%) of 1-phenethylamine from acetophenone by adding a small amount of acetic acid to methanol-ammonia with Raney Ni (eq. 6.6).15 The reductive amination of benzophenone in the presence of Raney Co and some ammonium acetate gave 70% yield ofbenzohy-drylamine, compared to only 19% under usual conditions with Raney Ni.3... 

Mylroie et al. studied the optimal conditions for reductive alkylation of A-(4-ni-trophenyl)acetamide with ketones using Pt-C and sulfided Pt-C.49 In general, the sulfided catalyst was superior in the yield of the alkylated amines. There was no indication of either reduction of the ketone or saturation of the ring. With a higher loading of ketone (6 equiv) at 100°C and 6.9 MPa H2 in ethanol, excellent yields (98.5-99%) of the alkylated amines were obtained from the reaction of acetone (eq. 6.24), cyclohexanone, 2-pentanone, and 3-pentanone with A-(4-ni-trophenyl)acetamide. 

The reductive coupling of amine 16f with 3-pentanone proceeds smoothly in the presence of NaCNBHs and acetic acid to ve the alkyiamine. Saponification of the methyl ester provides the molecule 16. 

Reduction of the hydroxyimino group with acetylation of the resulting amino group can be effected by zinc dust in the presence of acetic acid and acetic anhydride diethyl (acetylamino)malonate, which is important for amino acid syntheses, has been prepared in this way.97 Zinc dust reduces oximes of diaryl and arylalkyl ketones better in concentrated ammoniacal than in acid solution, giving the amines as very pure free bases whilst hardly any higher alkylated product is formed.98 Aminoacetone," diaminoacetone,100 and 2-afnino-3-pentanone" have been obtained by reducing oximes with tin or tin(n) chloride in alcoholic hydrochloric acid solution. In individual cases oximes have been reduced by sodium dithionite or aluminum amalgam.198 Further, the patent literature contains examples of electrolytic reduction of oximes.198... 

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