Carbamic acid

Source: Wikipedia, the free encyclopedia.
Not to be confused with Carbonic acid.
Carbamic acid
Structural formula of carbamic acid
Structural formula of carbamic acid
Ball-and-stick model of carbamic acid
Ball-and-stick model of carbamic acid
Names
Preferred IUPAC name
Carbamic acid[1]
Other names
Aminomethanoic acid
Identifiers
3D model (
JSmol
)
ChEBI
ChEMBL
ChemSpider
DrugBank
KEGG
MeSH Carbamic+acid
UNII
  • InChI=1S/CH3NO2/c2-1(3)4/h2H2,(H,3,4) checkY
    Key: KXDHJXZQYSOELW-UHFFFAOYSA-N checkY
  • InChI=1/CH3NO2/c2-1(3)4/h2H2,(H,3,4)
    Key: KXDHJXZQYSOELW-UHFFFAOYAC
  • O=C(O)N
Properties
NH3CO2
Molar mass 61.040 g·mol−1
Related compounds
Related compounds
 Formamide
Dithiocarbamate
Carbonic acid
Urea
Ethyl carbamate
Sulfamic acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Carbamic acid, which might also be called aminoformic acid or aminocarboxylic acid,

carboxyl groups –COOH.[4]

Carbamic acid could be seen as both an

hydroxyl group –OH attached to the carbon also excludes it from the amide
class.

The term "carbamic acid" is also used generically for any compounds of the form RR′NCOOH, where R and R′ are organic groups or hydrogen.[5]

Deprotonation of a carbamic acid yields a carbamate anion RR′NCOO−, the salts of which can be relatively stable. Carbamate is also a term used for esters of carbamic acids, such as methyl carbamate H2N−C(=O)−OCH3. The carbamoyl functional group RR′N–C(=O)– (often denoted by Cbm) is the carbamic acid molecule minus the OH part of the carboxyl.

Structure

Carbamic acid is a planar molecule.[3]

The H2N− group of carbamic acid, unlike that of most amines, cannot be

zwitterionic form H3N+−COO− is very unstable and promptly decomposes into ammonia and carbon dioxide,[6] yet there is a report of its detection in ices irradiated with high-energy protons.[3]

Derivatives

Carbamic acid is formally the parent compound of several important families of organic compounds:

Carbamic acids

Many substituted carbamic acids (RHNCOOH or RR′NCOOH), can be readily synthesized by bubbling carbon dioxide through solutions of the corresponding amine (RNH2 or RR′NH, respectively) in an appropriate solvent, such as DMSO or supercritical carbon dioxide.[5] These carbamic acids are generally unstable at room temperature, reverting to the parent amine and carbon dioxide.[7]

Carbamate esters

Unlike carbamic acids, carbamate esters are generally stable at room temperature as a higher state. They are prepared by reaction of carbamoyl chlorides with alcohols, the addition of alcohols to isocyanates, and the reaction of carbonate esters with ammonia.[8] Methyl carbamate and ethyl carbamate are among the simplest examples and have historically been used in the textile industry, both are now suspected carcinogens. Benzyl carbamate is also known.

Occurrence in nature

The enzyme class carbamate kinase, involved in several metabolic pathways of living organisms, catalyzes the formation of carbamoyl phosphate H2N−C(=O)−O−PO2−3:

ATP + NH3 + CO2 ⇌ ADP + H2N−C(=O)−O−PO2−3

An important example of an enzyme with this activity is carbamoyl phosphate synthetase, e.g. carbamoyl phosphate synthetase I carrying out the first step of the urea cycle in order to dispose of waste ammonia.

One

carbaminohaemoglobin
.

Uses

Industrial

Carbamic acid is an intermediate in the industrial production of urea, which involves the reaction of carbon dioxide and ammonia.[9]

CO2 + NH3 → H2NCOOH
H2NCOOH + NH3 → CO(NH2)2 + H2O

Medical

Some carbamate esters have use as

GABAA receptor.[10]

Insecticides

Several carbamic acid based insecticides have been developed; for example aldicarb, carbaryl, carbofuran.[11]

Chemical synthesis

An amine functional group −NH2 can be

ester bond
then produces a carbamic acid –NHC(=O)OH, which then loses carbon dioxide yielding the desired amine.

References

  1. ISBN 978-0-85404-182-4
    .
  2. ^ "PubChem Compound Summary for CID 277, Carbamic acid". National Center for Biotechnology Information. 2020. Retrieved October 10, 2020.
  3. ^ a b c d R. K. Khanna and M. H. Moore (1999): "Carbamic acid: molecular structure and IR spectra". Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, volume 55, issue 5, pages 961-967.
    Bibcode:1999AcSpA..55..961K
  4. doi:10.1051/0004-6361:200810536
  5. ^
    doi:10.1016/j.supflu.2006.08.012
  6. doi:10.1051/0004-6361:20066631
  7. ISBN 978-0-7817-4381-5
    .
  8. ISBN 3527306730
    .
  9. ISBN 978-3527306732
    .
  10. ISBN 978-0-7817-3481-3
    .
  11. PMID 3304999
    .
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