Sodium amide grinding

Sodium amide Mellor, 1943, Vol. 11, 234 Grinding a mixture leads to violent reaction. 

The sodium amide thus prepared is easily pulverized it may be ground in a mortar under any hydrocarbon solvent. It is safer, though not necessary, where ether is to be used as a reaction medium, to grind the amide first under a hydrocarbon, the mixture being transferred to the reaction flask and then replaced by ether in the usual way (Notes 15,16, and 17). 

The sodium amide was ground in an open mortar, and at no time was difficulty experienced. As a precautionary measure, the grinding could be carried out under ether. 

Caution. Extreme care should be taken in handling sodium amide, especially during the grinding of the material. Rubber gloves and a face mask should be worn, and the amide should be ground in small portions. Sodium amide, especially corroded pieces, has been reported to detonate without apparent cau.se. Contact with water should be carefully avoided. 

SAFETY PROFILE An intense irritant to dssue, skin, and eyes. Flammable by chemical reaction. Ignites or explodes with heat or grinding. Explosive reaction with moisture, chromium trioxide, potassium chlorate, halocarbons (e.g., l,l-diethoxy-2-chloroethane), oxidants, sodium nitrite, air. Can become explosive in storage. Violent reaction with dinitrogen tetraoxide. Will react with water or steam to produce heat and toxic and corrosive fumes of sodium hydroxide and ammonia. When heated to decomposition it emits highly toxic fumes of NH3 and Na20. See also AMIDES. 

Sodium diformylamide [18197-26-7] M 95.0. Grind the amide under diy tetrahydrofiiran (fiimehood), filter and wash it with this solvent, then dry it in vacuo. It is soluble in EtOH and H2O but insoluble in Et20 and pet ether. [IR and preparation Rakshit/C/iem Soc 103 1557 7975, Yinglin Hongwen 122... 

Reaction was also applied on coupling of aliphatic carboxyUc acids and amines (Table 3.14), and the chiral bis-amides were likewise obtained from diamines without the loss of chirality, suggesting that mechanochemical conditions are apphcable for the synthesis of chiral amides. In addition, several dipeptides 114 were prepared (Scheme 3.31). Racemization was not noticed which is the usual drawback of conventional solution-based procedures (Table 3.15). In dipeptide synthesis 2 equiv. of DMAP were used as the base to deprotonate the unprotected amino acid, and as the activator of EDC HCl and sodium chloride were added as the grinding auxiUary. 

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