p-Anisic Acid (4-Methoxybenzoic Acid) Frequently Asked Questions (FAQ)

p-Methoxybenzoic Acid Introduction

Chemical Name: p-Methoxybenzoic Acid

Synonyms: p-Anisic Acid, 4-Anisic Acid

CAS Number: 100-09-4

Molecular Formula: C8H8O3

Molecular Weight: 152.15 g/mol

I. Basic Information

p-Anisic acid (also known as 4-Methoxybenzoic acid) is a common organic aromatic acid with the molecular formula C₈H₈O₃ and a molecular weight of 152.15 g/mol. Its CAS Registry Number is 100-09-4. The substance typically appears as a white to off-white crystalline powder and exhibits stable physical and chemical properties.

II. Physicochemical Properties

The melting point of p-Anisic acid  is 182–185 °C, and its boiling point is approximately 275 °C (it may partially sublime or decompose upon heating). The density is approximately 1.385 g/cm³. Its solubility in water is limited, about 0.3 g/L at room temperature; however, it demonstrates good solubility in organic solvents such as ethanol, ether, and ethyl acetate. The acidity constant (pKa) is approximately 4.47.

III. Main Applications

p-Anisic acid is widely used as an intermediate in the synthesis of pharmaceuticals and agrochemicals, serving as an important raw material in these fields. Within the cosmetics and personal care industry, it can function as a preservative aid or fragrance component, finding application in skincare products and perfumes. Furthermore, this compound occurs naturally in plants like anise and vanilla and can serve as a flavor source (subject to compliance with relevant regulations). Additionally, it acts as a crucial intermediate in the synthesis of dyes, photographic chemicals, and other fine chemicals.

IV. Quality Standards Reference

Common quality specifications include: Appearance - White crystalline powder; HPLC Assay - Typically ≥98% or ≥99%; Melting Point - 182–185 °C; Water Content - ≤0.5%; Heavy Metals - Limit typically ≤10 ppm; Residual Solvents - Must comply with ICH Q3C guidelines. Actual data should be confirmed against the Certificate of Analysis (COA) provided by the manufacturer.

V. Analysis and Testing Methods

Analysis of this product can be performed using various methods. Commonly employed techniques are: Melting Point determination for purity assessment; ⊃1;H NMR and ⊃1;⊃3;C NMR for structure confirmation and purity evaluation; Infrared Spectroscopy (IR) for detecting characteristic peaks of the carboxylic acid and methoxy groups; HPLC or LC-MS are frequently used for qualitative and quantitative analysis; GC-MS can also be utilized, often after derivatization.

VI. Safety and Handling Recommendations

According to the MSDS, p-Anisic acid  may cause skin and eye irritation, be harmful if inhaled or swallowed, and poses certain hazards to the aquatic environment. It is recommended to wear protective gloves and safety glasses during handling to avoid direct contact. The product should be stored in a cool, dry, and dark place, kept in a sealed container, and separated from strong oxidizing agents, strong acids, and bases. Protect from moisture. Waste material should be disposed of in accordance with local regulations.

VII. Packaging and Storage & Transportation

Common packaging includes 25 kg cardboard drums with polyethylene liners. Customized packaging is available based on customer requirements. During transportation, the product should be protected from moisture and direct sunlight. It should be stored and transported according to standard chemical handling guidelines.

VIII. Quick Answers to Common Questions

Is p-Anisic acid soluble in water?

Its solubility in water is limited, approximately 0.3 g/L at room temperature.

What is the typical purity?

Standard specifications typically offer purities of ≥98% or ≥99% (by HPLC).

Can it be used in cosmetics?

Yes, this substance can be used as a fragrance or preservative aid, provided it complies with the relevant regulations of the target market.

Is a hazardous goods certificate required for transportation?

It is generally transported as a general chemical; however, all applicable national regulations and MSDS recommendations must be followed.