agent such as phosphorus(III) chlo-
ride, phosphorus(V) chloride, or sul-
phur dichloride oxide and is used to
introduce ethanoyl groups into or-
ganic compounds containing –OH,
–NH 2 , and –SH groups. See acylation.ethanoyl group (acetyl group) The
organic group CH 3 CO–.ethene(ethylene)A colourless
Ûammable gaseous hydrocarbon,
C 2 H 4 ; m.p. –169°C; b.p. –103.7°C. It is
theÜrst member of the *alkene se-
ries of hydrocarbons. It is made by
cracking hydrocarbons from petro-
leum and is now a major raw ma-
terial for making other organic
chemicals (e.g. ethanal, ethanol,
ethane-1,2-diol). It can be polymer-
ized to *polyethene. It occurs natu-
rally in plants, in which it acts as a
growth substance promoting the
ripening of fruits.ethenoneSee ketene.ethenyl ethanoate (vinyl acetate)
An unsaturated organic ester, CH 2 :
CHOOCCH 3 ; r.d. 0.9; m.p. –100°C;
b.p. 73°C. It is made by catalytic reac-
tion of ethanoic acid and ethene and
used to make polyvinylacetate.etherSee ethoxyethane; ethers.ethersOrganic compounds contain-
ing the group –O– in their molecules.
Examples are dimethyl ether,
CH 3 OCH 3 , and diethyl ether,
C 2 H 5 OC 2 H 5 (see ethoxyethane). They
are volatile highlyÛammable com-
pounds made by dehydrating alco-
hols using sulphuric acid.
A- Information about IUPAC nomenclature
ethoxyethane(diethyl ether;
ether)A colourlessÛammable
volatile ether, C 2 H 5 OC 2 H 5 ; r.d. 0.71;
m.p. –116°C; b.p. 34.5°C. It can be
made by *Williamson’s synthesis. Itis an anaesthetic and useful organic
solvent. See ethers.ethyl 3-oxobutanoate (ethyl
acetoacetonate)A colourless liquid
ester with a pleasant odour,
CH 3 COCH 2 COOC 2 H 5 ; r.d. 1.03; m.p.
<–80°C; b.p. 180.4°C. It can be pre-
pared by reacting ethyl ethanoate
(CH 3 COOC 2 H 5 ) with sodium or
sodium ethoxide. The compound
shows keto–enol *tautomerism and
contains about 7% of the enol form,
CH 3 C(OH):CHCOOC 2 H 5 , under nor-
mal conditions. Sometimes known as
acetoacetic ester, it is used in organic
synthesis.
ethyl acetateSee ethyl ethanoate.ethyl acetoacetonateSee ethyl 3-
oxobutanoate.ethyl alcoholSee ethanol.ethylamineA colourlessÛamma-
ble volatile liquid, C 2 H 5 NH 2 ; r.d. 0.69;
m.p. –81°C; b.p. 16.6°C. It is a pri-
mary amine made by reacting
chloroethane with ammonia and
used in making dyes.ethylbenzeneA colourlessÛam-
mable liquid, C 6 H 5 C 2 H 5 ; r.d. 0.867;
m.p. –95°C; b.p. 136°C. It is made
from ethene and ethybenzene by a
*Friedel–Crafts reaction and is used
in making phenylethene (for poly-
styrene).ethyl bromide See bromoethane.ethyleneSee ethene.
ethylenediamineSee 1,2-diamino-
ethane.ethylene glycolSee ethane-
1,2-diol.ethylene oxideSee epoxyethane.
ethyl ethanoate (ethyl acetate)A
colourlessÛammable liquid ester,
C 2 H 5 OOCCH 3 ; r.d. 0.9; m.p. –83.6°C;ethanoyl group 214e