4-methoxybenzoyl chloride

4-methoxybenzoyl chloride is an aromatic acyl chloride compound with the molecular formula C8H7ClO2 and CAS number 100-07-2. It features a benzene ring substituted with a methoxy group (-OCH3) at the para position and an acyl chloride group (-COCl). With a molecular weight of 170.59 g/mol, this compound is highly reactive due to its acyl chloride functionality, making it valuable in organic synthesis and chemical manufacturing processes.

4-methoxybenzoyl chloride is typically a white to pale yellow crystalline solid at room temperature with a pungent, acrid odor characteristic of acyl chlorides. It is highly reactive with water and alcohols, undergoing hydrolysis to form the corresponding carboxylic acid. The compound is soluble in organic solvents such as dichloromethane, chloroform, and benzene, but reacts vigorously with protic solvents like water and alcohols, releasing hydrogen chloride gas.

4-methoxybenzoyl chloride is primarily used as an intermediate in pharmaceutical and fine chemical synthesis. It serves as an acylating agent in the preparation of amides, esters, and other derivatives through reactions with amines and alcohols. The compound is valuable in manufacturing active pharmaceutical ingredients (APIs), agrochemicals, and specialty chemicals. It's particularly useful in research laboratories for organic synthesis reactions requiring selective acylation with the para-methoxybenzoyl protecting group.

4-methoxybenzoyl chloride requires careful handling due to its corrosive nature and reactivity with moisture. Always wear appropriate personal protective equipment including chemical-resistant gloves, safety goggles, and lab coats. Work in a well-ventilated area or fume hood to avoid inhalation of vapors or hydrogen chloride gas released upon contact with moisture. Use dry, inert conditions when possible, and ensure all equipment is moisture-free before handling to prevent unwanted hydrolysis reactions.

4-methoxybenzoyl chloride must be stored in tightly sealed, moisture-proof containers in a cool, dry place away from water and humidity. Keep containers in a well-ventilated area, preferably under inert gas atmosphere to prevent hydrolysis. Store away from incompatible materials such as alcohols, amines, and strong bases which can react violently. Use amber glass bottles or other light-resistant containers to prevent photodegradation, and ensure storage areas are equipped with appropriate spill containment measures.

Immediate action is required upon contact with 4-methoxybenzoyl chloride. For skin contact, immediately remove contaminated clothing and flush the affected area with plenty of water for at least 15 minutes. If inhaled, move to fresh air immediately and seek medical attention if breathing difficulties occur. For eye contact, rinse thoroughly with water for at least 15 minutes and remove contact lenses if present. Seek immediate medical attention for all exposure incidents and never induce vomiting if ingested.

4-methoxybenzoyl chloride waste must be disposed of according to local and national hazardous waste regulations. Small quantities can be carefully hydrolyzed with excess water or dilute base under controlled conditions to neutralize the acyl chloride functionality, forming the corresponding carboxylic acid. The resulting solution should then be treated as chemical waste. Larger quantities require disposal through licensed hazardous waste contractors. Never dispose of this material in regular waste streams or pour down drains.

4-methoxybenzoyl chloride is classified as ADR Class 8 (corrosive substances), Packing Group II, indicating moderate danger level for transportation. It must be packaged in approved containers suitable for corrosive materials and properly labeled with appropriate hazard markings. Transportation requires compliance with ADR regulations including proper documentation, vehicle placarding, and driver certification. Ensure packages are moisture-proof and provide adequate cushioning to prevent container damage during transit that could lead to leakage.

4-methoxybenzoyl chloride falls under various chemical regulations including REACH in Europe, requiring registration for commercial use above certain tonnage thresholds. It is not classified as a Substance of Very High Concern (SVHC) under REACH. Users must comply with CLP regulation for classification, labeling, and packaging requirements. Workplace exposure limits and safety data sheet provisions apply under occupational health regulations. Import/export may require permits depending on jurisdiction and intended use in pharmaceutical or chemical manufacturing.

4-methoxybenzoyl chloride is available through OYSI, a trusted European distributor of specialty chemicals and pharmaceutical intermediates. OYSI provides reliable supply chains for laboratory and industrial customers across Europe, ensuring proper handling, packaging, and documentation compliance with European regulations. Professional chemical suppliers like OYSI maintain appropriate storage conditions and provide technical support, safety data sheets, and certificates of analysis to meet customer requirements for research, development, and manufacturing applications.