Guanidine(redirected from Guanidines)
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(also carbamidine). (H2N)2C=NH, colorless hygroscopic crystals; melting point, approximately 50° C. Guanidine absorbs C02 and moisture from the air and forms salts with acids. On hydrolysis it gives urea and ammonia.
Guanidine (or its salts) is obtained by reacting cyanamide with ammonia (or with ammonium salts).
H2N—C≡N + NH3→(H2N)2C═NH
H2N —C≡N +NH4Cl→(H2N)2C═NH.HCI
Guanidine is used to obtain medicinal and explosive substances and ion-exchange resins. A guanidine fragment enters into the composition of guanine (a component of nucleic acids), creatine, and arginine, the antibiotic streptomycin, and tetrodotoxin, a poison of animal origin.