Calcium ethoxide, also known as calcium ethylate, is an organic calcium alkoxide with the CAS number 2914-17-2. It is an important basic reagent and intermediate in organic synthesis, valued for its strong basicity, moisture sensitivity, and clean reaction behavior. This article explains its chemical nature, key properties, main application fields, and the safety measures required when handling it.
What Is Calcium Ethoxide?
Calcium ethoxide has the formula Ca(OC2H5)2. It is an organic compound belonging to the family of metal alkoxides: the calcium cation is bonded to two ethoxide groups. In contrast to a common misconception, calcium ethoxide is an organic compound, not an inorganic one, because it contains carbon-based ethoxide ligands.
In its commercial form it is typically a white to off-white solid. The material is hygroscopic, meaning it absorbs moisture from the air, and it reacts readily with water, so it must be protected from atmospheric humidity during storage and use.
Key Physical and Chemical Properties
Appearance: white to off-white powder or granular solid.
Solubility: soluble in anhydrous ethanol and other lower alcohols; insoluble in common hydrocarbon solvents; decomposes in water.
Reactivity: reacts exothermically with water to form calcium hydroxide and ethanol.
Basicity: strongly basic, comparable to other alkaline earth alkoxides, which makes it useful as a catalyst and base in organic reactions.
Sensitivity: sensitive to moisture and carbon dioxide; prolonged exposure to air degrades the material.
Applications in the Pharmaceutical Industry
Calcium ethoxide is used as an intermediate and reagent in pharmaceutical synthesis. It serves as a base in the preparation of active pharmaceutical ingredients, supporting reactions such as esterification, condensation, and alkoxide-mediated substitutions. Because it is a mild and easily handled solid base, it can be used in processes where stronger or more soluble bases are impractical.
Its role in the synthesis of fine chemicals and pharmaceutical intermediates is well established, particularly in reactions where an ethoxide source or a basic catalyst is required under anhydrous conditions.
Applications in the Chemical and Agrochemical Industries
In the broader chemical industry, calcium ethoxide is employed as a catalyst in transesterification, condensation, and polymerization reactions. Transesterification processes, for example, benefit from the strong basicity of the alkoxide, which accelerates the exchange of ester groups under mild conditions.
In the agrochemical industry, calcium alkoxides participate in the synthetic pathways used to prepare pesticides and herbicides. The compound is also used as a reagent in the manufacture of specialty and fine chemicals, where its predictable stoichiometry and ease of handling are advantages over liquid alkoxide solutions.
Safe Handling and Storage Guidelines
Because calcium ethoxide is moisture-sensitive and reacts with water, storage and handling must exclude humidity. Store the material in tightly sealed containers under a dry atmosphere, ideally in a desiccator or under an inert gas blanket such as nitrogen. Keep containers away from sources of water, acids, and ignition.
When handling calcium ethoxide, wear chemical-resistant gloves, safety goggles, and protective clothing. Work in a well-ventilated area or under a fume hood. Avoid dust formation and inhalation of airborne particles. In case of skin or eye contact, rinse immediately with plenty of water and seek medical advice if irritation persists. Dispose of waste material according to local chemical waste regulations.
Frequently Asked Questions
What is the CAS number of calcium ethoxide?
The CAS number of calcium ethoxide is 2914-17-2.
Is calcium ethoxide an organic or inorganic compound?
It is an organic compound. It belongs to the metal alkoxide family, with the formula Ca(OC2H5)2, and contains carbon-based ethoxide groups.
How should calcium ethoxide be stored?
It should be stored in tightly sealed containers in a cool, dry place, protected from moisture and air. An inert atmosphere such as nitrogen is recommended for long-term storage.
What happens when calcium ethoxide reacts with water?
It reacts exothermically with water to produce calcium hydroxide and ethanol. For this reason, water must be kept away from the material during storage and handling.
What is calcium ethoxide used for in organic synthesis?
It is used as a basic catalyst and reagent in transesterification, condensation, esterification, and polymerization reactions, and as an intermediate in pharmaceutical and agrochemical synthesis.
Is calcium ethoxide soluble in common solvents?
It dissolves in anhydrous lower alcohols such as ethanol, but is insoluble in hydrocarbon solvents and decomposes in water.