Title: Biguanide
CAS Registry Number: 56-03-1
CAS Name: Imidodicarbonimidic diamide
Additional Names: guanylguanidine; amidinoguanidine; diguanide
Molecular Formula: C2H7N5
Molecular Weight: 101.11
Percent Composition: C 23.76%, H 6.98%, N 69.26%
Literature References: Preparation from dicyanodiamide: Rackmann, Ann. 376, 169 (1910); Karipides, Fernelius, Inorg. Synth. 7, 56, 58 (1963). Crystal structure: S. R. Ernst, F. W. Cagle, Acta Crystallogr. 33B, 235 (1977); S. R. Ernst, ibid. 237.
Properties: Crystals from alc, mp 130°; dec rapidly at about 142°. Sol in water, alcohol. Insol in ether, benzene, chloroform. The aq soln dec on standing or heating. Aq solns are alkaline. Biguanide is a stronger base (pK1 = 11.52; pK2 = 2.93) than ammonia (pK = 9.61).
Melting point: mp 130°
pKa: pK1 = 11.52; pK2 = 2.93; pK = 9.61
Derivative Type: Hydrochloride
Molecular Formula: C2H7N5.HCl
Molecular Weight: 137.57
Percent Composition: C 17.46%, H 5.86%, N 50.91%, Cl 25.77%
Properties: Needles, mp 235°, very sol in water, slightly sol in alc.
Melting point: mp 235°
Derivative Type: Neutral sulfate
Molecular Formula: (C2H7N5)2.H2SO4.2H2O
Molecular Weight: 336.33
Percent Composition: C 14.28%, H 5.99%, N 41.65%, S 9.53%, O 28.54%
Properties: Large crystals, sol in water.
Derivative Type: Acid sulfate
Molecular Formula: C2H7N5.H2SO4.H2O
Molecular Weight: 217.20
Percent Composition: C 11.06%, H 5.10%, N 32.24%, S 14.76%, O 36.83%
Properties: Rhombic prisms, sol in water, the soln giving an acid reaction.
Use: Sulfates in the determination of copper and nickel.
Bikhaconitine Bilberry Bilirubin Biliverdine Bimosiamose

Skeletal formula of biguanide
Ball and stick model of biguanide
CAS number 56-03-1 YesY
PubChem 5939
ChemSpider 5726 YesY
EC number 200-251-8
KEGG C07672 YesY
Beilstein Reference 507183
Gmelin Reference 240093
Jmol-3D images Image 1
Image 2
Molecular formula C2H7N5
Molar mass 101.11 g mol−1
Related compounds
Related compounds
  • Dimethylamine
  • Trimethylamine
  • Unsymmetrical dimethylhydrazine
  • N-Nitrosodimethylamine
  • Dithiobiuret
  • Diethylamine
  • Triethylamine
  • Diisopropylamine
  • Dimethylaminopropylamine
  • Diethylenetriamine
  • N,N-Diisopropylethylamine
  • Triisopropylamine
  • Tris(2-aminoethyl)amine
  • Mechlorethamine
  • HN1 (nitrogen mustard)
  • HN3 (nitrogen mustard)
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references
Buformin. Note extra butyl at bottom right.
Phenformin. Note extra phenyl at right.

Biguanide can refer to a molecule, or to a class of drugs based upon this molecule. Biguanides can function as oral antihyperglycemic drugs used for diabetes mellitus or prediabetes treatment. They are also used as antimalarial drugs.

The disinfectant polyaminopropyl biguanide (PAPB) features biguanide functional groups.