[28321-79-1] · C4H2N4 · Diiminosuccinonitrile · (MW 106.09)
Alternate Name: DISN.
Physical Data: mp 165-166 °C (dec); sublimes at 100 °C/1 mmHg; heat of combustion 5.09 kcal g-1;4 dipole moment 1.59 D.
Solubility: (25 °C, g 100 mL-1): acetone (21), THF (21), MeCN (18), DMAc (5.9), ether (1.5); insol benzene and hydrocarbons.
Preparative Method: a solution of dry Triethylamine (1.5 mL) in CH2Cl2 (15 mL) is added dropwise over 45 min to a solution of Hydrogen Cyanide (20 g, 0.74 mol) and cyanogen (17.4 g, 0.34 mol) in CH2Cl2 (120 mL) at -45 to -40 °C; the reaction is mildly exothermic and DISN precipitates as the triethylamine is added; after 30 min the product is collected while still cold and washed with CH2Cl2 and ether to give 33.6 g (95%) of DISN as a fine tan powder of sufficient purity for synthetic use.4
Purification: dissolve in hot ethyl acetate with
Darco treatment, evaporate the solution to a slush, suction filter, and wash the solid with ether and dry in inert atmosphere; an air-stable white crystalline solid is obtained.
Handling, Storage, and Precautions: oral toxicity is ALD 90 mg/kg in rat; causes severe irritation on contact with rabbit eyes and permanent damage is prevented only by immediate flushing with water; causes mild skin and nose irritation; use only in a fume hood or in very well-ventilated areas with adequate protection (it produces HCN when wet or in contact with hydroxylic solvents); slowly discolors on exposure to light, and decomposes in water (t1/2 about 2 weeks at ambient conditions).
DISN is similar in reactivity to benzoyl cyanide in reactions with alcohols and aromatic amines. Dimethyloxaldiimidate is formed when DISN is treated with methanol under acid or base catalysis (eq 1).3 Depending on the conditions, from neutral, to an equivalent amount of acid, to strong acidic medium, the reaction between DISN and o-phenylenediamine can afford three different products (eq 2).3 DISN also has the same reactivity toward Diaminomaleonitrile (eq 3), although only one example is shown here.5
Oxalyl cyanide can be isolated from controlled hydrolysis of DISN (eq 4).3
DISN undergoes [4 + 2] cycloadditions with electron-rich alkenes (eq 5).2a
2,2-Dimethyl-4,5-dicyanoisoimidazole is formed in high yield by the addition of DISN to 2,2-Dimethoxypropane under acidic conditions (eq 6).3
DISN reacts with Sulfur Dichloride or seleninyl chloride in methylene chloride to give dicyano-1,2,5-thiadiazole3 or dicyano-1,2,5-selenadiazole (eqs 7 and 8).6
Trifluoroacetic Anhydride reacts with DISN to yield 4,5-dicyano-2-hydroxy-2-trifluoromethyl-2H-imidazole (eq 9).7
Seung Hoon Cheon
Sandoz Research Institute, East Hanover, NJ, USA