Acetoxyacetyl chloride CAS 13831-31-7 Purity 97% percent Colorless to Pale Yellow Fuming Liquid Pharmaceutical Intermediate Acylation Reagent

1. Product Overview

Acetoxyacetyl chloride, CAS 13831-31-7, also known as 2-acetoxyacetyl chloride or (chlorocarbonyl)methyl acetate, is an acyl chloride derivative of acetoxyacetic acid with molecular formula C4H5ClO3 and MW 136.53 g/mol. It appears as a clear colorless to pale yellow fuming liquid at room temperature with a pungent irritating odor. Boiling point approximately 55 degrees Celsius at 12 mmHg or 70–72 degrees Celsius at 15 mmHg, density 1.27 g/mL at 25 degrees Celsius, refractive index n20/D 1.428. It is miscible with common organic solvents such as ether, chloroform, dichloromethane and acetic acid, but reacts violently with water and alcohols to release HCl gas and form acetoxyacetic acid or esters. This compound is moisture- and air-sensitive, stored under anhydrous inert conditions, and serves as a key acylating agent and pharmaceutical intermediate for taxane anticancer APIs such as paclitaxel and herbicide mefenacet (benthiocarb acetamide).

2. Key Features and Advantages

• Highly Reactive Acyl Chloride — Enables rapid amide and ester formation with amines and alcohols under mild conditions; dual acetoxy and acyl chloride functionality for stepwise protection/deprotection.

• Pharma Critical Intermediate — Core building block for paclitaxel side-chain assembly, beta-lactam synthesis, roxatidine precursor, and benthiocarb herbicide intermediate.

• Commercially Available Grades — Reagent 97–98% HPLC/GC, industrial 98–99% tech grade; supplied in sealed ampoules or aluminum-capped bottles under dry N2/Ar.

• Controlled Stability — Though hydrolytically unstable, can be handled in dry solvent systems and stored refrigerated under strict anhydrous protocol.

3. Main Applications

Used in acyl chloride and pharma sectors: Pharmaceutical Intermediates (side-chain acylation for paclitaxel/docetaxel synthesis; roxatidine acetate precursor; beta-lactam and glycolylhydroxamic acid scaffolds); Agrochemical Synthesis (intermediate for herbicide mefenacet / benthiocarb acetamide via acetoxyacetyl chloride coupling); Organic Synthesis Acylation Reagent (amide bond formation from amines, esterification of alcohols, introduction of acetoxyacetyl protecting group in peptide/medicinal chemistry); Custom Synthesis (mg–kg scale acyl chlorides for CRO/CDMO pipelines, inquire-only; also used in stabilized spiro-beta-lactam conformer preparation).

4. Technical Specifications

5. Storage and Handling

• Storage Conditions: Store in a cool, dry place under inert atmosphere N2 or Ar, strictly anhydrous. Keep in sealed amber glass ampoules or aluminum-capped bottles with desiccant. Recommended: 2–8 °C refrigerator for reagent; –20 °C for long term; never store uncovered. Industrial bulk in dry-area locked corrosive cabinet, <30 °C, RH <40%.

• Packaging Options: Reagent: 1 g / 5 g / 25 g / 100 g sealed ampoules or screw-cap vials under N2; Industrial: 1 kg / 25 kg / 200 kg HDPE or iron drums with nitrogen blanketing; tonner IBC on inquiry.

• Shelf Life: ≥12 months unopened at 2–8 °C under dry N2; once opened use immediately under dry box/N2 stream.

• Handling Precautions: Handle in fume hood with face shield, acid-gas respirator, nitrile gloves, neoprene apron. Avoid all contact with water/moisture; use dry syringes/tools. Ground containers to prevent static. Incompatible with water, alcohols, amines, strong bases.

6. Safety Overview

GHS pictograms GHS05 Corrosion GHS07 Exclamation. Signal Word Danger. Hazard statements H314 causes severe skin burns and eye damage, H335 may cause respiratory irritation, H318 causes serious eye damage. Precautionary P261 P280 P305+P351+P338 P310. Reacts violently with water releasing HCl gas (R14/R34). Acute toxicity: corrosive to skin/eyes/respiratory tract; oral LD50 not reported but treat as highly corrosive acyl chloride. Transport UN 3265 Corrosive Liquid n.o.s., Class 8 PG II. WGK Germany 3. Customs 29183000. For pharma intermediate/research only; neutralize before disposal as corrosive halogenated waste. Skin: brush off excess, flush with copious water then soap; eyes: irrigate 15 min + immediate medical aid; inhalation: move to fresh air, O2 if needed, seek medical help.