US 5,332,824 AGranted

Process for the preparation of 2-amino-5-methyl-pyridine

AssigneeBayer Aktiengesellschaft

InventorsEric Rivadeneira, Klaus Jelich

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Abstract

The invention relates to a novel process and novel intermediates for the preparation of 2-amino-5-methylpyridine (I) ##STR1## The process is characterized in that in a first step 3-methyl-pyridine 1-oxide of the formula (II) ##STR2## is reacted with a trialkylamine of the general formula (III) R.sub.3 N (III) in which R represents alkyl, and with an electrophilic compound, in the presence or absence of a diluent, to give the ammonium salt of the general formula (IV) ##STR3## in which R has the abovementioned meaning and Z.sup..crclbar. represents an anion formed from an electrophilic compound, the compound (IV) is, possibly, isolated as a crude intermediate and, possibly, further purified and then in a second step the ammonium salt of the formula (IV) is reacted with hydrogen bromide, in the presence or absence of a diluent, at temperatures between 150.degree. C. and 300.degree. C. The compound (I) is an intermediate for the preparation of agrochemicals, for example of herbicides.

Claims9

Dependent claims

A process for the preparation of 2-amino-5-methylpyridine of the formula ##STR20## which comprises in a first step reacting 3-methyl-pyridine 1-oxide of the formula ##STR21## with a trialkylamine of the formula

(R).sub.3 N (III)
in which
R is C.sub.1 -C.sub.4 -alkyl,
and with an electrophilic compound selected from the group consisting of acetyl chloride, propionyl chloride, acetic anhydride, propionyl anhydride, benzoyl chloride, benzotrichloride, phosgene, oxalyl chloride, benzene sulfonyl chloride, p-toluene sulfonyl chloride, phosphorous (111)chloride, phosphorous oxy chloride, phosphorous (V) chloride, thionyl chloride, sulfonyl chloride dichloromethylene-dimethyl-immonium chloride, cyanuric chloride and chlorotrimethyl-silane, in the presence or absence of a diluent, to given the ammonium salt of the formula ##STR22## in which Z is an anion from the electrophilic compound,
optionally isolating the compound (IV), optionally purifying the compound (IV), optionally cleaving the compound (IV) into an alkyl compound RZ and a 2-dialkylamino-5-methyl-pyridine of the formula ##STR23## and then in a second step reacting the compound (IV) or (V) with hydrogen bromide at a temperature between 150.degree. and 300.degree. C.

2 more elements

Dependencies are inferred from the claim text.