Acetyl Chloride

Abstract

Abstract [75-36-5]?C2H3ClO?(MW 78.50) InChI?=?1S/C2H3ClO/c1-2(3)4/h1H3 InChIKey?=?WETWJCDKMRHUPV-UHFFFAOYSA-N (useful for electrophilic acetylation of arenes, alkenes,a, alkynes, saturated alkanes,a, organometallics, and enolates (on C or O); for cleavage of ethers; for esterification of sterically unhindered or acid-sensitive alcohols; for generation of solutions of anhydrous hydrogen chloride in methanol; as a dehydrating agent; as a solvent for organometallic reactions; for deoxygenation of sulfoxides; as a scavenger for chlorine and bromine; as a source of ketene; and for nucleophilic acetylation) Physical Data:?bp 51.8?°C;a mp ?112.9?°C;a d 1.1051 g cm?3;a refractive index 1.38976.b IR (neat) ? 1806.7 cm?1; 1H NMR (CDCl3) δ 2.66 ppm; 13C NMR (CDCl3) δ 33.69 ppm (q) and 170.26 ppm (s); the bond angles (determined by electron diffraction) are 127.5° (O?C?C), 120.3° (O?C?Cl), and 112.2° (Cl?C?C). Analysis of Reagent Purity:?a GC assay for potency has been described; to check qualitatively for the presence of HCl, a common impurity, add a few drops of a solution of crystal violet in chloroform; a green or yellow color indicates that HCl is present, while a purple color that persists for at least 10 min indicates that HCl is absent.b Preparative Methods:?treatment of Acetic Acid or sodium acetate with the standard inorganic chlorodehydrating agents (PCl3,b, SO2Cl2,a, or SOCl2b,) generates material that may contain phosphorus- or sulfur-containing impurities.b,a, Inorganic-free material can be prepared by treatment of HOAc with Cl2CHCOCl (?; 70%), PhCOCl (?; 88%), PhCCl3 (cat. H2SO4, 90?°C; 92.5%), or phosgene (optionally catalyzed by DMF,e magnesium or other metal salts,a,b,d or activated carbonb,c), or by addition of hydrogen chloride to acetic anhydride (85?90?°C; ?practically quantitative?).a, Purification:?HCl-free material can be prepared either by distillation from dimethylanilinec, or by standard degassing procedures.c, Handling, Storage, and Precautions:?acetyl chloride should be handled only in a well-ventilated fume hood since it is volatile and toxic via inhalation. It should be stored in a sealed container under an inert atmosphere. Spills should be cleaned up by covering with aq sodium bicarbonate.a