Semicarbazide-hydrochloride Details
semicarbazide hydrochloride. Its chemical formula is CH₅N₃O��HCl and its molecular weight is 111.53 g/mol.Semicarbazide
hydrochloride is a derivative of urea, which is an organic compound
that contains two amine groups and a carbonyl group. Semicarbazide
hydrochloride belongs to the class of carboxylic acid hydrazides, which are compounds that have a carboxylic acid group (COOH) replaced by a hydrazine group (NHNH₂).
Some of the physical properties of semicarbazide hydrochloride are:
-
Color: white to light cream
-
Shape: crystalline powder
-
Odor: odorless
-
Density: 1.286 g/cm³
-
Melting point: 176 ��C (decomposes)
-
Boiling point: 235.3 ��C at 760 mmHg
-
Flash point: 66.5 ��C
-
Solubility: soluble in water (>100 g/L at 15 ��C), insoluble in absolute alcohol and ether
-
Refractive index: 1.544 (estimated)
-
Electrical conductivity: not available
Some of the chemical properties of semicarbazide hydrochloride are:
-
Stability: stable under normal conditions, decomposes when heated above melting point
-
Reactivity: reacts with strong oxidizing agents and bases
-
Acidity: weakly acidic, pKa = 5.0
-
Redox potential: not available
Semicarbazide hydrochloride can be prepared by various methods, such as:
-
Reacting carbon monoxide with hydrazine at high pressure and temperature in the presence of a metal carbonyl catalyst
-
Reacting nitrourea with hydrogen in the presence of a hydrogenation catalyst, hydrochloric acid and an inert solvent
-
Reacting urea with hydrazine hydrate at reflux temperature and then adding anhydrous hydrogen chloride
-
Reacting hydrazine sulfate with potassium cyanate and then adding hydrochloric acid
One example of a preparation method is given below:
OC(NH2)2+N2H4−>OC(NH2)(N2H3)+NH3OC(NH2)(N2H3)+HCl−>OC(NH2)(N2H3)∗HCl
Urea (60.1 g, 1 mole) and 64% aqueous hydrazine solution (55 g, 1.10
moles) were placed in a 250 ml, 3-neck flask and heated at reflux
(115��-120�� C.) for three hours evolving gaseous ammonia. After the
reaction was finished, the mixture was cooled to 70 ��C, and 1.8 mol of
hydrochloric acid solution was added dropwise with stirring. The mixture
was stirred for another 40 minutes, then cooled to 15 ��C and filtered.
The precipitate was dissolved again in absolute ethyl alcohol, filtered,
and dried under vacuum at 120 ��C to obtain the target product.
Semicarbazide hydrochloride has various uses and effects in different fields, such as:
-
Pharmaceutical: it is used as a raw material for synthesizing
nitrofuran antibacterials (such as furazolidone, nitrofurazone,
nitrofurantoin) and related compounds, which have antiviral,
antiinfective and antineoplastic activities
-
Chemical analysis: it is used as a reagent for detecting carbonyl
compounds as their semicarbazones, which produce crystalline compounds
with characteristic melting points. It is also used as a solvent for
chromatographic analysis and hormone separation
-
Heterocyclic synthesis: it is used as a building block for
synthesizing various heterocyclic compounds, such as pyrazoles,
pyrazolines, pyrazolidines, triazoles, etc.
-
Other: it is used as a urease substrate and a monoamine oxidase inhibitor10. It is also used as a pesticide and a photosensitive material
Semicarbazide hydrochloride is a hazardous substance that should be handled with care. Some of the safety precautions are:
-
Wear appropriate protective gloves, clothing, and eye/face protection
-
Do not eat, drink or smoke when using this product
-
Avoid breathing dust or fumes
-
Wash hands and skin thoroughly after handling
-
Store in a cool, dry and well-ventilated place
-
Dispose of the waste according to local regulations
-
Seek medical attention if exposed or in case of any adverse effects
