Boron trifluoride diethyl etherate

Chemical Properties

Colorless to brown fuming liquid.

uses

Boron trifluoride diethyl etherate is used as a Lewis acid catalyst in Mukaiyama aldol addition, alkylation, acetylation, isomerization, dehydrations and condensation reactions. It is involved in the prepattion of polyethers in polymerization reactions. As a catalyst, it is used in the preparation of cyclopentyl- and cycloheptyl[b]indoles and other diborane. It is also used in sensitive neutron detectors in ionization chambers as well as monitoring radiation levels in earth’s atmosphere.

Preparation

Boron trifluoride gas, produced by heating the sulfuric acid, calcium fluoride (fluorite) and boric acid together, reacts with ether boron to produce the trifluoride etherate crude product, thus we can refine it to get the finished product. The consumption of raw material is as followed: boric acid (≥98%), 560kg/t; calcium fluoride(≥90%) 1150kg/t; fuming sulfuric acid (104.5%), 4100kg/t; ether(≥99%) 725kg/t.
In absorption method shown in the chemical equations as followed, diethyl ether absorb boron trifluoride gas, produced by heating the sulfuric acid, calcium fluoride (fluorite) and boric acid together, to produce trifluoride etherate crude complex compound by vacuum distillation.
3H2SO4+2H33BO3+3CaF2→2BF3+3CaSO4+6H2O
BF3+(C2H5)2O→(C2H5)2O•BF3

Toxicity

See boron trifluoride.

Chemical Properties

Boron trifluoride etherates: (compounded with methyl ether) is moisture-sensitive, corrosive, flammable liquid.

Physical properties

Fuming liquid; stable at ambient temperatures but hydrolyzed on exposure to moist air; density 1.125 g/mL; refractive index 1.348; solidifies at -60.4°C; boils at 125.7°C; flash point (open cup) 147°F (68.8°C); decomposes in water.

Uses

Boron trifluoride diethyl etherate is used as a Lewis acid catalyst in Mukaiyama aldol addition, alkylation, acetylation, isomerization, dehydrations and condensation reactions. It is involved in the prepattion of polyethers in polymerization reactions. As a catalyst, it is used in the preparation of cyclopentyl- and cycloheptyl[b]indoles and other diborane. It is also used in sensitive neutron detectors in ionization chambers as well as monitoring radiation levels in earth?s atmosphere.

Uses

Catalyst in acetylation, alkylation, polymerization, dehydration, and condensation reactions.

Application

Catalyst in the synthesis of polyol chains. Reagent for the coupling of imines to allylstannanes and 4′-nitrobenzenesulfenanilide to alkenes and alkynes.
Lewis acid reagent with broad application
Catalyst used in the preparation of cyclopentyl- and cycloheptyl[b]indoles from aryl cyclopropyl ketones via [3+2] cycloaddition.

Preparation

Boron trifluoride etherate is prepared by the reaction of vapors of boron trifluoride with that of anhydrous diethyl ether:
BF₃ (g) + (C₂H₅)₂O (g) → (C₂H₅)₂O?BF₃.

General Description

Boron trifluoride etherate is a fuming liquid. Boron trifluoride etherate may be corrosive to skin, eyes and mucous membranes. Boron trifluoride etherate may be toxic by inhalation. Upon exposure to water Boron trifluoride etherate may emit flammable and corrosive vapors. Boron trifluoride etherate is used as a catalyst in chemical reactions.

Air & Water Reactions

Highly flammable. Fuming liquid, immediately hydrolyzed by moisture in air to form hydrogen fluoride [Merck 11th ed. 1989].

Reactivity Profile

Boron trifluoride diethyl ether complex is a stable, highly flammable, colourless to brown fuming, corrosive liquid with a sharp pungent odour. It forms explosive peroxides in contact with air or oxygen. It reacts exothermically with water to form extremely flammable diethyl ether and toxic, corrosive boron trifluoride hydrates. The chemical is incompatible with bases, amines, and alkali metals. It immediately gets hydrolysed by moisture in air to form hydrogen fluoride. Boron trifluoride diethyl ether has applications in chemical laboratory as a catalyst in chemical reactions.

Hazard

The compound is highly toxic by inhalation. Skin contact causes burns.

Health Hazard

May cause toxic effects if inhaled or ingested/swallowed. Contact with substance may cause severe burns to skin and eyes. Fire will produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control or dilution water may cause pollution.

Fire Hazard

Flammable/combustible material. May be ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water.

Flammability and Explosibility

Flammable

Potential Exposure

Used as a catalyst.

Shipping

Diethyl: UN2604 Boron trifluoride diethyl etherate, Hazard class: 8; Labels: 8—Corrosive material, 3—Flammable liquid. Dimethyl: UN2965 Boron trifluoride dimethyl etherate, Hazard class: 4.3; Labels: 4.3— Dangerous when wet, 8—Corrosive material, 3— Flammable liquid.

Incompatibilities

Reacts with air forming corrosive hydrogen fluoride vapors. Incompatible with oxidizers (may cause fire and explosion), water, steam or heat, forming corrosive and flammable vapors. Peroxide containing etherate reacts explosively with aluminum lithium hydride, magnesium tetrahydroaluminate. Mixtures with phenol react explosively with 1,3-butadiene. Presumed to form explosive peroxides.