Methy lamine production

A Ag/Pd-cathode hydrogenates 2-butyne-1,4-diol and acetylene dicarboxylic acid exclusively to the cis-olefin [323]. Similar results were obtained at a Cu net covered with spongy silver [324]. With dimethyl butynedioate the cis/trans ratio of the product dimethyl butenedioate on a Pd black cathode decreased with increasing pH both in electrolytic and catalytic hydrogenation [325]. On the other side at a Hg cathode a trans addition to alkynes occurs [326]. In methy-lamine/liCl, dialkylacetylenes are reduced to trans-olefins. Nonconjugated aromatic internal acetylenes are selectively reduced to aromatic trans-olefins [327]. 

Reduction in liquid NH3 and NaCl at Pt electrodes gives a 90% yield of a mixture consisting of 85% (A) (Fig. 60) and 14% (C) [329]. The hydrogenations in methy-lamine or ammonia are cathodic Birch reductions in which the final protonation of the intermediate anion leads to the thermodynamically more favorable trans product. 

Raw materials. N-methyl taurine is the reaction product of sodium isethionate and methy-lamine (see Figure 4.28). Taurine can be made by using ammonia instead of methylamine, but has little use in surfactants. 

The cathode potential necessary for the production of solvated electrons is rather negative the standard potential of the hydrated electron has been calculated to be —2.68 V versus NHE. Also, in other solvents compatible with its formation, very negative potentials must be used for example, in liquid ammonia the generation of ens is achieved at —2.47 V versus Ag/AgN03 (0.1 M) [306], but the dissolution standard potential measured in HMPA was found to be —3.44 V versus Ag/AgC104 (0.1 M) [307]. Similarly, in methy-lamine f — 50°C), a potential of —2.90 V versus Ag/AgN03 was reported [308]. 

The odor of fish is due primarily to amines, especially methy-lamine (CH3NH2). Fish is often served with a wedge of lemon, which contains citric acid. The amine and the acid react forming a product with no odor, thereby making the less-than-fresh fish more appetizing. Using data from Appendix D, calculate the equilibrium constant for the reaction of citric acid with methylamine, if only the first proton of the citric acid (Kgi) is important in the neutralization reaction. 

Amino Rosins. Amino resins are the reaction product of an aldehyde with a compound containing an amino (—NH2) group (see Amino Resins). Both urea and melamine react with formaldehyde, first by addition to form methy-lol compounds, and then by condensation to form cross-linked polymers through methylene bridge and methylene ether formation. The cross-linking reactions are exothermic and produce water and formaldehyde as volatile products in reactions similar to resole phenolics, illustrated in equation 3. Urea-formaldehyde and melamine-formaldehyde account for the bulk of the amino resins. Their characteristics include water solubility and unlimited colorability with dyes and pigments. Applications include decorative high pressure phenolic laminates, adhesives in the laminated wood and furniture industries, and as an additive to textile fabrics to impart wash and wear properties. 

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