Dicyano-diamide

Also known as nitrolim and lime nitrogen. The fresh product contains approximately 55 per cent, of calcium cyanamide, 20 p>er cent, of lime, 12 per cent, of graphite and small amounts of other impurities. It should be protected from moisture when stored in order to prevent slow polymerisation to dicyano-diamide. 

The filtrate contains guanidine nitrate along with a small amount of ammonium nitrate and very small amounts of dicyano-diamide and biguanide nitrate (Note 6). The solution is concentrated to about 1 1. and the guanidine nitrate which crystallizes on cooling is filtered off. A second crop is obtained by... 

The green synthesis of 6-aryl-2,4-diamino-l,3,5-triazines (xviii) from corresponding aryl-nitriles and dicyano diamide using computer controlled microwave irradiation in conjugation with a green solvent [bmim] [PFg] has also been achieved [30]. 

The mercapto group can also be formed via the isothiouronium salt (Andriska et al., 1962b Kniisli et al., 1962). With thiourea 2-chloro-4,6-bis(alkylamino)-5-triazines give isothiouronium salt in a practically quantitative yield this is then decomposed by alkali to the corresponding mercapto compound and dicyano diamide. From this, the 2-mercapto-4,6-bis(alkylamino)-s-triazinc derivative is obtained with a methylating agent. The reaction scheme is as follows ... 

In its manufacture, methyl ethyl ketone is condensed with ethylcyanoacetate to give ethyl-2-cyano-3-methyl-2-pentenoate. That, in turn, adds HCN to give ethyl-2,3-dicyano-3-methyl-pentanoate. Saponification and decarboxylation gives 2-methyl-2-ethyl succinonitrile. Heating with aqueous NH3 gives the diamide which loses NHj and cyclizes to ethosuximide. 

Typical procedure. 2,9-Dicyano-l,W-phenanthroline 1391 [1058] To DMF (200 mL), oxalyl chloride (5.7 mL, 0.066 mol) was added with stirring at 0 °C under argon atmosphere. A white precipitate formed immediately, which was accompanied by gas evolution. When the gas evolution had ceased, a solution of the diamide 1390 (7.0 g, 0.026 mol) in DMF (150 mL) was added to the reaction flask. The resulting yellow mixture was stirred for 6 h at 0 °C. Pyridine (9.4 mL, 0.116 mol) was then added and, after stirring for a further 30 min, the mixture was neutralized with saturated aq. Na2C03 solution (500 mL). Some precipitate was formed, and precipitation was completed by adding water (700 mL). After filtration, the pale-yellow... 

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