Cyanamide
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Names | |||
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IUPAC name
Cyanamide
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Other names
Amidocyanogen, carbamonitrile, carbimide, carbodiimide, cyanoamine, cyanoazane, N-cyanoamine, cyanogenamide, cyanogen amide, cyanogen nitride, diiminomethane, hydrogen cyanamide, methanediimine
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Identifiers | |||
3D model (
JSmol ) |
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3DMet | |||
ChEBI | |||
ChEMBL | |||
ChemSpider | |||
DrugBank | |||
ECHA InfoCard
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100.006.358 | ||
EC Number |
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784 | |||
KEGG | |||
PubChem CID
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RTECS number
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UNII | |||
UN number | 2811 | ||
CompTox Dashboard (EPA)
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Properties | |||
CH2N2 | |||
Molar mass | 42.040 g/mol | ||
Appearance | Crystalline solid | ||
Density | 1.28 g/cm3 | ||
Melting point | 44 °C (111 °F; 317 K) | ||
Boiling point | 260 °C (500 °F; 533 K) (decomposes) 83 °C at 6.7 Pa 140 °C at 2.5 kPa | ||
85 g/100 ml (25 °C) | |||
Solubility in organic solvents | soluble | ||
log P | -0.82 | ||
Acidity (pKa) | 10.3[1] | ||
Hazards | |||
GHS labelling: | |||
Danger | |||
H301, H311, H314, H317, H351, H361, H373, H412 | |||
P201, P202, P260, P261, P264, P270, P272, P273, P280, P281, P301+P310, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P308+P313, P310, P312, P314, P321, P322, P330, P333+P313, P361, P363, P405, P501 | |||
NFPA 704 (fire diamond) | |||
Flash point | 141 °C (286 °F; 414 K) | ||
NIOSH (US health exposure limits): | |||
PEL (Permissible)
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none[2] | ||
REL (Recommended)
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TWA 2 mg/m3 | ||
IDLH (Immediate danger) |
N.D.[2] | ||
Safety data sheet (SDS) | ICSC 0424 | ||
Related compounds | |||
Related compounds
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Calcium cyanamide | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Cyanamide is an
Tautomers and self-condensations
Containing both a nucleophilic and electrophilic site within the same molecule, cyanamide undergoes various reactions with itself. Cyanamide exists as two tautomers, one with the connectivity N≡C–NH2 and the other with the formula HN=C=NH ("carbodiimide" tautomer). The N≡C–NH2 form dominates, but in a few reactions (e.g. silylation) the diimide form appears to be important.[3]
Cyanamide dimerizes to give 2-cyanoguanidine (dicyandiamide). This dimerization is hindered or reversed by acids and is inhibited by low temperatures. The cyclic trimer is called melamine.[3]
Production
Cyanamide is produced by hydrolysis of
- CaCN2 + H2O + CO2 → CaCO3 + H2NCN
The conversion is conducted on slurries.
Reactions and uses
Cyanamide can be regarded as a functional single carbon fragment which can react as an electrophile or nucleophile. The main reaction exhibited by cyanamide involves additions of compounds containing an acidic proton. Water, hydrogen sulfide, and hydrogen selenide react with cyanamide to give urea, thiourea, and selenourea, respectively:
- H2NCN + H2E → H2NC(E)NH2 (E = O, S, Se)
In this way, cyanamide behaves as a dehydration agent and thus can induce condensation reactions. Alcohols, thiols, and amines react analogously to give alkylisoureas, isothioureas, and
The cyanamide
A convenient method for the preparation of secondary amines which are not contaminated with primary or tertiary amines is the reaction of cyanamide with alkyl halides to N,N-dialkylcyanamides which can easily be hydrolyzed to dialkylamines and then decarboxylated.[5] Cyanamide adds itself in the presence of N-bromosuccinimide to olefinic double bonds. The addition product is converted by bases to N-Cyanaziridine,[6] cyclized in the presence of acids to imidazolines, which can be further reacted to vicinal diamines by alkaline cleavage.[7]
Cyanamide is also a versatile synthetic building block for heterocycles: it forms 2-aminobenzimidazole with 1,2-diaminobenzene[8] and it forms with the readily available cyclic enamine 4-(1-cyclohexenyl)morpholine[9] and with elemental sulfur a 2-aminothiazole in good yields.[10]
Sodium dicyanamide is available in good yield and high purity from cyanamid and cyanogen chloride,[11][12] which is suitable as an intermediate for the synthesis of active pharmaceutical ingredients.[13] A guanidino group is introduced by reaction of cyanamide with sarcosine In the industrial synthesis of creatine:[14].
This synthesis route mostly avoids problematic impurities like chloroacetic acid, iminodiacetic acid, or dihydrotriazine that occur in other routes. The physiological precursor guanidinoacetic is obtained analogously by reacting cyanamide with glycine.
Methods to stabilize cyanamidefmel make it available on an industrial scale. Due to the strong affinity towards self-condensation in alkaline media (see above) solutions of cyanamide are stabilized by the addition of 0.5 wt% of monosodium phosphate as buffer. Solid cyanamide is produced by careful evaporation of the solvent and subsequent addition of a hydrolysis-labile ester of formic acid. The ester absorbs traces of moisture (suppression of urea formation), neutralizes alkalinity (ammonia) and continually releases small amounts of formic acid.[15]
Agricultural use
Cyanamide, under the trade name Dormex, is a common agricultural
A 50% aqueous solution of cyanamide is also used as a biocide (disinfectant) particularly in pig farming, because it effectively kills salmonella and shigella and fights flies in all stages of development.[17]
Environmental aspects
Cyanamide degrades via hydrolysis to urea, an excellent fertilizer.
Cyanamide functional group
Cyanamide is the name for a functional group with the formula R1R2N−C≡N where R1 and R2 can be a variety of groups. These compounds are called cyanamides. One example is naphthylcyanamide, C10H7N(CH3)CN, which has been produced by the
Cyanamide in space
Due to its high permanent dipole moment (i.e., 4.32 ± 0.08 D),
Safety
It is used as an
Cyanamide has a modest toxicity in humans.
References
- ^ "Cyanamide_msds".
- ^ a b NIOSH Pocket Guide to Chemical Hazards. "#0160". National Institute for Occupational Safety and Health (NIOSH).
- ^ ISBN 978-3527306732.
- .
- .
- PMID 5439242.
- ..
- ..
- doi:10.15227/orgsyn.041.0065).
{{cite journal}}
: CS1 maint: multiple names: authors list (link - ..
- ^ .
- ^ Verfahren zur Herstellung von Natrium-Dicyanamid, veröffentlicht am 10. August 2000, Anmelder: SKW Trostberg AG.
- ^ "Sodium dicyanamide (Na-dicyanamide)". lonza.com. Archived from the original on 2013-05-23. Retrieved 2019-07-01.
- ^ Deutsche Offenlegungsschrift DE-OS 10 2006 016 227 A1, Offenlegungsdatum: 11. Oktober 2007, Anmelder: Degussa GmbH
- PMID 19505756.
- ^ Powell, A. (1999). "Action Program for Dormex Application on Peaches". Auburn University. Archived from the original on 2018-06-20.
- ^ "ALZOGUR®". AlzChem (in German). Retrieved 2019-07-01.
- .
- .
- ISBN 0-471-60180-2
- .
- doi:10.1086/181963.
- ^ S2CID 6961576.
External links
- International Chemical Safety Card 0424
- NIOSH Pocket Guide to Chemical Hazards. "#0160". National Institute for Occupational Safety and Health (NIOSH).
- OSHA guideline for cyanamide