4-Methoxybenzoyl chloride

The hydrolysis of 4-Methoxybenzoyl chloride (OMe) generally occurs through a  dissociative mechanism (SN1). The reaction  rate is strongly affected by the polarity of the medium and the  ability to stabilize the leaving group. Water encapsulated within a reverse micellar system is less polar and less available compared to a continuous aqueous phase; Consequently, the hydrolysis of OMe in the micellar medium is slower than in pure water.

p-Anisoyl chloride, also known as 4-methoxybenzoyl chloride, is an amber-colored crystalline solid with a melting point of 72 °F. It is corrosive to metals and skin. Its vapors may cause serious burns to the eyes. It decomposes upon contact with water or alcohols but is soluble in acetone and benzene. Storage in sealed containers may cause explosion due to pressure build-up from decomposition; it must be stored at low temperatures (5°C).

4-Methoxybenzoyl chloride is used in the synthesis of stilbene and dihydrostilbene derivatives as potential anti-cancer agents. It is also used in the synthesis of coumarin dimers with potential HIV-1 activity.

4-Methoxybenzoyl chloride is synthesized from the direct chlorination of 4-methoxybenzoic acid by thionyl chloride.

4-Methoxybenzoyl chloride is a commonly employed acylating agent for protecting amino and hydroxyl groups. Its versatility is demonstrated in various applications within pharmaceutical intermediates and organic synthesis:

1. It acts as a radical precursor in visible-light photocatalysis for synthesizing heterocyclic compounds.
2. It is utilized to prepare acylphosphine ligands, which are effective in the rhodium-catalyzed hydrosilylation of alkenes.
3. Incorporation of 4-methoxybenzoyl chloride modified indium tin oxide (ITO) as cathode for the fabrication of organic light-emitting diodes (OLEDs) has been reported.
4. It serves as a starting material for 1,3-diketones, enabling the one-pot synthesis of pyrazole derivatives.
5. It can also be used in the total synthesis of bioactive compounds like echinoside A and salinosporamide A.

4-Methoxybenzoyl chloride reacts with nucleophilic compounds, including alcohols, amines, and water, facilitating the formation of esters, amides, and carboxylic acids, respectively. This reactivity is attributed to the presence of the methoxy group, which, through resonance, stabilizes the acyl chloride moiety, making it an effective intermediate in the synthesis of more complex organic molecules.

4-Methoxybenzoyl chloride is one of the reactive acylating agents that can react with carboxylic acids, alcohols and amines to yield respective carboxylic anhydrides, esters and amides. 4-methoxybenzoyl chloride reacts with potassium thiocyanate to yield isothiocyanate derivative via nucleophilic addition-elimination mechanism.

Fumes in air. Reacts exothermically with water (including moisture in air or soil) to form hydrochloric acid and insoluble anisic acid [Merck 11th ed. 1989].

ANISOYL CHLORIDE reacts exothermically with bases, including amines. Incompatible with water, strong oxidizing agents, alcohols. Sealed containers held at room temperature may explode, due to slow decomposition that builds up pressure. This situation is more dangerous with heat. May react vigorously or explosively with diisopropyl ether or other ethers in the presence of trace amounts of metal salts [J. Haz. Mat., 1981, 4, 291].

Solutions corrosive to tissue. Explosion risk when in closed containers due to pressure caused by decomposition at room temperature.

Vapor irritates mucous membranes. Contact of liquid with eyes or skin causes severe irritation. Ingestion causes severe irritation of mouth and stomach.

Special Hazards of Combustion Products: Irritating hydrogen chloride fumes may be formed.

Not classified

Reactivity with Water Reacts slowly to generate hydrogen chloride (hydrochloric acid). The reaction is not hazardous; Reactivity with Common Materials: Corrodes metal slowly; Stability During Transport: Stable; Neutralizing Agents for Acids and Caustics: Flush with water, rinse with sodium bicarbonate or lime solution; Polymerization: Not pertinent; Inhibitor of Polymerization: Not pertinent.

4-Methoxybenzoyl chloride is used in the synthesis of stilbene and dihydrostilbene derivatives as potential anti-cancer agents. It is also used in the synthesis of coumarin dimers with potential HIV-1 activity.

4-Methoxybenzoyl chloride can be used as radical precursor in visible-light photocatalysis to synthesize various heterocyclic compounds. Incorporation of 4-methoxybenzoyl chloride modified indium tin oxide (ITO) as cathode for the fabrication of organic light-emitting diodes (OLEDs) has been reported.

Corrosive to skin, eyes, mucous membranes, and other tissue.Evolves HCl by hydrolysis. A storage hazard; can explode spontaneously at room temperature. When heated to decomposition it emits toxic fumes of Cland may explode.

Stored in a closed container can cause an explosion due to the pressure caused by decomposition, should be stored at low temperature (5°C).

Anisoyl chloride, also known as methoxybenzoyl chloride), is an acyl halide, specifically an aromatic acyl chloride, and may be formed from anisic acid by replacing a hydroxyl group of the carboxylic acid with a chloride group. There are three isomers: the ortho-, meta-, and para- forms. 4-Methoxybenzoyl chloride is para- forms. Their structures differ in the arene substitution pattern—the location of the methoxy group on the ring as compared to the acyl halide.