General Description
A colorless fuming liquid with a pungent odor. Flash point 162°F. Lachrymator, irritating to skin and eyes. Corrosive to metals and tissue. Density 10.2 lb/gal. Used in medicine and in the manufacture of other chemicals.
Reactivity Profile
BENZOYL CHLORIDE reacts violently with protic solvents such as alcohols, with amines and amides (for example dimethylformamide [Bretherick 1979 p. 6] ) and with inorganic bases. Causes the violent decomposition of dimethyl sulfoxide [Chem. Eng. News 35(9): 87 1957]. May react vigorously or explosively if mixed with diisopropyl ether or other ethers in the presence of trace amounts of metal salts [J. Haz. Mat., 1981, 4, 291]. Friedel-Crafts acylation of naphthalene using benzoyl chloride, catalyzed by AlCl3, must be conducted above the melting point of the mixture, or the reaction may be violent [Clar, E. et al., Tetrahedron, 1974, 30, 3296].
Hazard
Highly toxic. Strong irritant to skin, eyes,
and mucous membranes, and via ingestion, inhala-
tion. Upper respiratory tract irritant. Probable car-
cinogen.
Health Hazard
INHALATION: may irritate eyes, nose and throat. INGESTION: causes acute discomfort. SKIN: causes irritation and burning.
Potential Exposure
Benzoyl chloride is used as a chemical
intermediate; in organic synthesis; to produce other chemicals,
dyes, perfumes, herbicides, and medicines.
First aid
If this chemical gets into the eyes, remove any
contact lenses at once and irrigate immediately for at least
15 minutes, occasionally lifting upper and lower lids. Seek
medical attention immediately. If this chemical contacts the
skin, remove contaminated clothing and wash immediately
with soap and water. Seek medical attention immediately.
If this chemical has been inhaled, remove from exposure,
begin rescue breathing (using universal precautions, including
resuscitation mask) if breathing has stopped and CPR if
heart action has stopped. Transfer promptly to a medical
412 Benzoyl Chloride
facility. When this chemical has been swallowed, get medical
attention. If victim is conscious, administer water or
milk. Do not induce vomiting. Medical observation is
recommended for 24 to 48 hours after breathing overexposure,
as pulmonary edema may be delayed. As first aid for
pulmonary edema, a doctor or authorized paramedic may
consider administering a drug or other inhalation therapy.
Shipping
UN 1736 Benzoylchloride, Hazard class: 8;
Labels: 8—Corrosive material.
Incompatibilities
May form explosive mixture with air.
Contact with heat, hot surfaces, and flames causes decomposition,
forming phosgene and hydrogen chloride. Water
contact may be violent; forms hydrochloric acid. Reactions
with amines, alcohols, alkali metals, dimethyl sulfoxide,
strong oxidizers, and metal salts may be violent, causing
fire and explosions. Attacks metals in the presence of
moisture, forming explosive hydrogen gas. Attacks some
plastics, rubber or coatings.
Description
Benzoyl chloride is a colorless to slightbrown liquid with a strong, penetrating odor. Molecularweight = 140.57;Boiling point = 197.2℃ at 760 mmHg;Freezing/Melting point= 2 1℃; Flash point = 72℃;Vapor pressure =0.38 mmHg at 20℃; Autoignitiontemperature=197℃. Explosive limits in air:Lower=2.5%; Upper=27%.Hazard Identification(based on NFPA-704 M Rating System): Health 3,Flammability 2, Reactivity 2 (water reactive).Decomposes in water.
Chemical Properties
Benzoyl chloride is a colorless to slight brown
liquid with a strong, penetrating odor.
Chemical Properties
Transparent, colorless liquid; pungent
odor; vapor causes tears. Soluble in ether and carbon disulfide;
decomposes in water. Combustible.
Waste Disposal
Pour into sodium bicarbonate
solution and flush to sewer.
Uses
Benzoyl Chloride is used in the manufacturing of dye intermediates.
Uses
For acylation, i.e., introduction of the benzoyl group into alcohols, phenols, and amines (Schotten-Baumann reaction); in the manufacture of benzoyl peroxide and of dye intermediates. In organic analysis for making benzoyl derivatives for identification purposes.
Definition
A liquid acyl chloride used as a benzoylating
agent.
Production Methods
Benzoyl chloride can be prepared from benzoic acid by reaction with PCl5 or SOCl2, from benzaldehyde by treatment with POCl3 or SO2 Cl2, from benzotrichloride by partial hydrolysis in the presence of H2SO4 or FeCl3, from benzal chloride by treatment with oxygen in a radical source, and from several other miscellaneous reactions. Benzoyl chloride can be reduced to benzaldehyde, oxidized to benzoyl peroxide, chlorinated to chlorobenzoyl chloride and sulfonated to m-sulfobenzoic acid. It will undergo various reactions with organic reagents. For example, it will add across an unsaturated (alkene or alkyne) bond in the presence of a catalyst to give the phenylchloroketone:图
Chemical Reactivity
Reactivity with Water Slow reaction with water to produce hydrochloric acid fumes. The reaction is more rapid with steam; Reactivity with Common Materials: Slow corrosion of metals but no immediate danger; Stability During Transport: Not pertinent; Neutralizing Agents for Acids and Caustics: Soda ash and water, lime; Polymerization: Does not occur; Inhibitor of Polymerization: Not pertinent.
Mechanism of action
Indicative of its high reactivity (relative to alkyl chlorides), benzyl chloride reacts with water in a hydrolysis reaction to form benzyl alcohol and hydrochloric acid. In contact with mucous membranes, hydrolysis produces hydrochloric acid. Thus, benzyl chloride is a lachrymator and has been used in chemical warfare. Theoretically, for every mole of benzyl chloride reacted, one mole of hydrochloric acid is released[1].
Safety Profile
Confirmed carcinogen withexperimental tumorigenic data by skin contact. Humansystemic effects by inhalation: unspecified effects onolfaction and respiratory systems. Corrosive effects on theskin, eyes, and mucous membranes by inhalation.Flammable whe
Toxicology
Benzoyl chloride is of low acute oral toxicity in
rats (LD50 2529 mg/kg). It is more toxic by
inhalation (LC50 230 ppm, 4 h in male rats and
314 ppm, 4 h in female rats). The compound is
irritating to skin, mucous membranes, eyes, and
the respiratory tract.
When benzoyl chloride or solutions of benzoyl chloride in benzene were applied to the skin of
mice for up to 10 months irritation and keratinization resulted, and to some extent, ulceration
and necrosis of the skin occurred. A few tumors
(skin, lung) were observed in those mice.
There is no clear evidence that benzoyl chloride
is mutagenic.
For humans, benzoyl chloride is classified as a
lachrymator. It is irritating to the skin, eyes, and
mucous membranes. The available data are
inadequate to evaluate the carcinogenic potential
of benzoyl chloride to humans.
storage
(1) Color Code—Red Stripe: FlammabilityHazard: Do not store in the same area as other flammablematerials. Color Code—White: (2) Corrosive or ContactHazard; Store separately in a corrosion-resistant location.Store in a cool, dry, well-ventilated area preferably in adetached warehouse. Keep away from sources of ignition.Avoid physical damage to the container.
Purification Methods
A solution of benzoyl chloride (300mL) in *C6H6 (200mL) is washed with two 100mL portions of cold 5% NaHCO3 solution, separated, dried with CaCl2 and distilled [Oakwood & Weisgerber Org Synth III 113 1955]. Repeated fractional distillation at 4mm Hg through a glass helices-packed column (avoiding porous porcelain or silicon-carbide boiling chips, and hydrocarbon or silicon greases on the ground joints) gave benzoyl chloride that did not darken on addition of AlCl3. Further purification is achieved by adding 3 mole% each of AlCl3 and toluene, standing overnight, and distilling off the benzoyl chloride at 1-2mm [Brown & Jenzen J Am Chem Soc 80 2291 1958]. Refluxing for 2hours with an equal weight of thionyl chloride before distillation has also been used. [Beilstein 9 IV 721.] Strong IRRITANT. Use in a fume cupboard.
References
[1] Tsonis C, et al. 26 - Polybenzyls. 1989; 5: 455-464.
