US 5,491,239 A · Method for halogenating an aromatic compound

Abstract

A method for halogenating an aromatic compound, which comprises reacting the aromatic compound of the formula (I): ##STR1## wherein X is a hydroxyl group, an amino group or an acylamino group, each of Z.sub.1 and Z.sub.2 is a hydrogen atom or a halogen atom, one of R and Y is a hydrogen atom and the other is a nitro group, a cyano group or a trifluoromethyl group, and Q is a nitrogen atom or --C(T).dbd. (wherein T is a hydrogen atom, a halogen atom, a nitro group, a cyano group or a trifluoromethyl group), with a halogenating agent to obtain a 3-halogenoaromatic compound of the formula (II): ##STR2## wherein one of R' and Y' is a halogen atom and the other is a nitro group, a cyano group or a trifluoromethyl group, and X, Z.sub.1, Z.sub.2 and Q are as defined above.

Claims10

Dependent claims

A method for halogenating pyridine, which comprises reacting a pyridine of the formula (I'):

##STR17## wherein X is amino;
each of Z.sub.1 and Z.sub.2 is hydrogen or halogen;
one of R and Y is hydrogen and the other is nitro, cyano or trifluoromethyl;
with a halogenating agent to form a 3-halogenopyridine of the formula (II'):
##STR18## wherein one of R' and Y' is halogen and the other is nitro, cyano, or trifluoromethyl;
and X, Z.sub.1 and Z.sub.2 are as defined above,
wherein the pyridine of the formula (I') is reacted with a halogenating agent to form a halogenopyridine of the formula (III'):
##STR19## wherein E is --N(A)--Hal, wherein A is hydrogen;
and Hal is halogen;
and Z.sub.1, Z.sub.2, R and Y are as defined above, and said halogenopyridine of the formula (III') is subjected to a rearrangement reaction in the presence of a proton donor to form the 3-halogenopyridine of the formula (II').

7 more elements

Dependencies are inferred from the claim text.

Method for halogenating an aromatic compound

Life of this patent

Method for halogenating an aromatic compound

Life of this patent

Abstract

Claims10