cyanamide

Cyanamide
IUPAC name	Cyanamide, aminomethanenitrile
Other names	Amidocyanogen, carbamonitrile, carbimide, carbodiimide, cyanoamine, cyanoazane, N-cyanoamine, cyanogenamide, cyanogen nitride, hydrogen cyanamide
Identifiers
CAS number	420-04-2 Y
PubChem	9864
EC number	206-992-3
UN number	2811
RTECS number	GS5950000
SMILES	N#CN
Properties
Molecular formula	CH2N2
Molar mass	42.040 g/mol
Appearance	Crystalline solid
Density	1.28 g/cm3
Melting point	44 °C
Boiling point	260 °C (decomp.) 83 °C at 6.7 Pa 140 °C at 2.5 kPa
Solubility in water	85 g/100 ml (25 °C)
Solubility in organic solvents	soluble
Hazards
MSDS	ICSC 0424
EU Index	615-013-00-2
EU classification	Toxic (T)
R-phrases	R21, R25, R36/38, R43
S-phrases	(S1/2), S3, S22, S36/37, S45
NFPA 704	1 4 3
Flash point	141 °C
Related compounds
Related compounds	Calcium cyanamide
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Cyanamide is an organic compound with the formula CN₂H₂. This white solid is widely used in synthetic organic chemistry as well as in agriculture. It is also used as an alcohol deterent drug in Canada, Europe and Japan, but not in the United States. The molecule features a nitrile group attached to an amino group. Although it is similar in structure to hydrogen cyanide, it is not as toxic. Derivative of this compound are also referred to as cyanamides, the most common being calcium cyanamide (CaCN₂).

Production, reactions, uses

Cyanamide is produced by hydrolysis of calcium cyanamide, which in turn is prepared from calcium carbide via the Frank-Caro process.

CaCN₂ + H₂O + CO₂ → CaCO₃ + H₂NCN

The conversion is conducted on slurries, consequently most commercial cyanamide is sold as an aqueous solution.

The main reaction exhibited by cyanamide involves additions of protic reagents. Water, hydrogen sulfide, and hydrogen selenide add to give urea, thiourea, and selenourea, respectively:

H₂NCN + H₂E → H₂NC(E)NH₂ (E = O, S, Se)

Thus, cyanamide is a dehydration agent and thus can induce condensation reactions. Alcohols, thiols, and amines react analogously to give alkylisoureas, "pseudothioureas," and guanidines. The anti-ulcer drug cimetidine is generated using such reactivity. Related reactions exploit the bifunctionality of cyanamide to give heterocycles, and this latter reactivity is the basis of several pharmaceutical syntheses such as the aminopyrimidine imatinib) and agrichemicals Amitrol (3-Amino-1,2,4-triazole) and Hexazinone. The hair-loss treatment Minoxidil and the anthelmintic (worm-killing) drugs Albendazole, Flubendazole, and Mebendazole feature 2-aminoimidazole substructures derived from cyanamide.^[1]

Environmental aspects

Cyanamide degrades via hydrolysis to urea, an excellent fertilizer. Microorganisms, e.g. the bacterium Myrothecium verrucaria, accelerate this process utilizing the enzyme cyanamide hydratase.

Safety

Cyanamide has a modest toxicity in humans.^[2] Workplace exposure to hydrogen cyanamide sprays or exposure in people living in the vicinity of spraying have been reported as causing respiratory irritation, contact dermatitis, headache, and gastrointestinal symptoms of nausea, vomiting, or diarrhea.^[2]

References

External links

• International Chemical Safety Card 0424
• NIOSH Pocket Guide to Chemical Hazards 0160
• OSHA guideline for cyanamide