Methylamine, from nitromethane

Methylamine occurs in herring brine 2 in crude methyl alcohol from wood distillation,3 and in the products obtained by the dry distillation of beet molasses residues.4 It has been prepared synthetically by the action of alkali on methyl cyanate or iso-cyanurate 5 by the action of ammonia on methyl iodide,6 methyl chloride,7 methyl nitrate,8 or dimethyl sulfate 9 by the action of methyl alcohol on ammonium chloride,10 on the addition compound between zinc chloride and ammonia,11 or on phos-pham 12 by the action of bromine and alkali on acetamide 13 by the action of sodamide on methyl iodide 14 by the reduction of chloropicrin,15 of hydrocyanic or of ferrocyanic acid,16 of hexamethylenetetramine,17 of nitromethane,18 or of methyl nitrite 19 by the action of formaldehyde on ammonium chloride.20... 

At a time when the only practicable methods for the preparation of nitromethane were the interaction of methyl iodide with silver nitrite and the Kolbe reaction from chloracetic acid, the explosive was far too expensive to merit consideration. The present cheap and large scale production of nitromethane by the vapor-phase nitration of methane and of ethane has altered the situation profoundly. Trimethylolnitromethane trinitrate is an explosive which can now be produced from coke, air, and natural gas. Nitromethane too has other interest for the manufacturer of explosives. It may be used as a component of liquid explosives, and it yields on reduction methylamine which is needed for the preparation of tetryl. 

Nitro-2-methyl-3-butanol and l-nitro-2-octanol were hydrogenated in aqueous ethanol solution in the presence of oxalic acid and acetic acid, respectively, to give 76 and 69.5% yields of the hydroxylamine oxalates. In one patent, nitromethane (684 g, 11.2 mol) was hydrogenated over 2 g of 5% Pd-C in 60% aqueous H2S04 (1010 g, 6.18 mol)-toluene (684 g), as a water-immiscible solvent, at 50°C and 4.1 MPa H2 and a 92% of jV-methylhydroxylamine sulfate was obtained from the aqueous phase together with 6% of methylamine sulfate.29... 

The first of these alternative approaches started with commercially available indanone-3-carboxylic acid 23 (derived from phenylsuccinic anhydride via Friedel-Crafts chemistry). This indanone was a viable precursor to 6 through an aminomethyl homologation with cyanide or nitromethane (Scheme 3.10). Our intent was to obtain ester 25, which after reduction would afford methylamine 28, which in turn would cyclize to generate lactam 29, giving benzazepine 6 upon reduction. Stereocontrol in the homologation was unnecessary, as lactam 29 would theoretically provide a thermodynamic sink under epimerizing reaction conditions, capturing the desired di-indane isomer. 

Similarly to the nitropropene, 4-hydroxy-3-methoxy-a>-nitrostyrene is prepared from the appropriately substituted benzaldehyde and nitromethane in the presence of methylamine as catalyst.974 The following illustrates a slight variant of the technique ... 

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