Water, amide reactions boiling point

A vigorously stirred suspension of 0.2 to 1 mole of sodium amide in 200 ml of xylene, in which were dissolved 0.1 mole of a,a-diphenyl-7-hexamethyleneimino butyronitrile was boiled for 12 hours. Thereupon the excess of sodium amide was decomposed with water and the xylene layer was separated, washed with water and extracted with hydrochloric acid. This acidic extract was made strongly alkaline with concentrated lye and the separated base was extracted with ether. After drying, the ether was evaporated and the l,l-diphenyl-3-hexamethyleneimino propane distilled in vacuo. The boiling point was 170-174°C/1 mm, the refractive index nD20 = 1.56 36, and the density d420 = 1.009. From the oil obtained several acid additions and quaternary ammonium salts can be obtained by reaction with acids containing a non-toxic anion or esters thereof. The hydrochloric acid salt, for instance, melts at 189-192°C, the methiodide at 174-177°C under decomposition. 

To a suspension of 3.12 g of sodium amide in 50 ml dry toluene was added dropwise 12 g of 2-(dimethylamino)ethylaminopyridine. The mixture was refluxed for 2 hours, cooled to 50°C, and 21 g 3-thenyl bromide was added dropwise. When reaction subsided, the brownish-orange mixture was refluxed for 0.5 hour, cooled, and poured into 150 ml of water. The toluene layer was separated, extracted with 5% hydrochloric acid. This extract was saturated with potassium carbonate. The free base was extracted with ether, dried and fractionated. Yield of N,N-dimethyl-N -2-pyridinyl-N -(3-thienylmethyl)-l,2-ethanediamine 31%, boiling point 169-172°C/1 mm. 

Esters, tertiary amides, and nitriles are frequently used as solvents for organic reactions because they provide a polar reaction medium without O—H or N—H groups that can donate protons or act as nucleophiles. Ethyl acetate is a moderately polar solvent with a boiling point of 77 °C, convenient for easy evaporation from a reaction mixture. Acetonitrile, dimethylformamide (DMF), and dimethylacetamide (DMA) are highly polar solvents that solvate ions almost as well as water, but without the reactivity of O—H or N—H groups. These three solvents are miscible with water and are often used in solvent mixtures with water. 

Besides water for hydrothermal reactions, liquid ammonia (bp, 78°C Tc, 132°C Pc, 113 atm) is also used for the solvothermal synthesis of nitrides. Metastable or otherwise unobtainable nitride materials were reported to be formed by this rnethod. " Ammonium and amide (NH2) ions are the strongest acid and base, respectively, for the liquid ammonia system, and therefore ammonium salt acts as the acid mineralizer, while amide ion can be prepared by addition of alkali metals to the solvent. Since ammonia has a low boiling point, the reaction pressure is usually quite high. 

AEROTEX GLYOXAL 40 (107-22-2) Flammable solid, but normally sold as an inhibited 40% solution. A highly reactive reducing agent. Violent reaction with water causes polymerization. Temperatures above boiling point of 122°F/50°C can cause polymerization. Reacts, possibly violently, with strong acids, caustics, ammonia, amines, amides, aldehydes, chlorosulfonic acid, ethylene amine, hydroxyl-containing materials. Corrosive to metals aluminum, copper, tin, steel, zinc. 

The reaction, referred to as amidation, is a reversible reaction. Amide formation is maximized by forcing the equilibrium to the right by removal of water via running the reaetion above the boiling point of water. Amide formation is the reaction by which polypeptides and proteins are synthesized in biologieal systems. 

---