Unformatted text preview: 642 AMINES (e) Conversion of o-ﬂuoroanisole to 4-amino-2-ﬂuoroanisole proceeds in the conventional way
by preparation and reduction of a nitro derivative. Once the necessary arylamine is at hand, it
is converted to the nitrile by a Sandmeyer reaction.
Diazotization followed by hydrolysis of the 4-amino-2-ﬂuoroanisole prepared as an intermediate in part (d ) yields the desired phenol.
1. NaNO2, H2SO4, H2O as in part (d ) 2. heat NH2
o-Anisidine 22.41 (a) OH 4-Amino-2fluoroanisole 3-Fluoro-4methoxyphenol
(70%) The carboxyl group of p-aminobenzoic acid can be derived from the methyl group of
p-methylaniline by oxidation. First, however, the nitrogen must be acylated so as to protect the
ring from oxidation.
CO2H CO2H CH3 NH2 NHCCH3 NH2 O
acid p-Methylaniline The sequence of reactions to be used is
CH3 CH3 OO
CH3COCCH3 CO2H CO2H K2Cr2O7, H2SO4 NH2 1. HCl, H2O H2O, heat 2. neutralize HNCCH3
O (b) O p -Methylacetanilide p -Methylaniline HNCCH3
p -Acetamidobenzoic acid O F Main Menu NH2 CCH2CH3 Ethyl p -fluorophenyl
ketone Forward p -Aminobenzoic acid Attachment of ﬂuoro and propanoyl groups to a benzene ring is required. The ﬂuorine substituent can be introduced by way of the diazonium tetraﬂuoroborate, the propanoyl group by
way of a Friedel– Crafts acylation. Because the ﬂuorine substituent is ortho, para-directing,
introducing it ﬁrst gives the proper orientation of substituents.
F Back NH2 TOC Fluorobenzene Study Guide TOC Aniline Student OLC MHHE Website ...
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