Process for preparing esters of 3-amino-4-halobenzoic acid
OwnerThomas Shanks, Robert Maleskiinventors
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Abstract
Disclosed is a process for producing good yields of high quality esters of 3-amino-4-halobenzoic acid by contacting the subject acid with an alkyl halide or sulfonate in a solvent in the presence of an aqueous alkali metal hydroxide and a phase transfer catalyst comprising tetrasubstituted ammonium or phosphonium salt.
Claims16
A process for producing a 3-amino-4-halobenzoic acid ester which comprises contacting 3-amino-4-halobenzoic acid with an alkyl halide or sulfonate in the presence of an aqueous alkali metal hydroxide, a solvent, and a tetrasubstituted ammonium or phosphonium salt.
A process for producing a 3-amino-4-chlorobenzoic acid ester which comprises contacting 3-amino-4-chlorobenzoic acid with RX1 in the presence of sodium hydroxide or potassium hydroxide, water, a solvent and a phase transfer catalyst, wherein R is a branched or straight chain C6-C20 alkyl group and X1 is chloride, bromide, iodide, methanesulfonate, p-toluenesulfonate, or benzene sulfonate.
A process for producing a 3-amino-4-chlorobenzoate ester which comprises contacting an alkali metal salt of 3-amino-4-chlorobenzoic acid with RX1 in the presence of water, a solvent, and a tetrasubstituted ammonium or phosphonium salt, wherein R is a branched or straight chain C6-C20 alkyl group and X1 is chloride, bromide, iodide, methanesulfonate, p-toluenesulfonate, or benzene sulfonate.
A process for producing a 3-amino-4-chlorobenzoic acid ester which comprises:
- contacting 3-amino-4-chlorobenzoic acid with RX1 in the presence of water, sodium or potassium hydroxide, a solvent, and a phase transfer catalyst;
- and
- distilling to remove water, wherein R is hexyl, octyl, 2-ethylhexyl, dodecyl or hexadecyl;
- X1 is chloride, bromide, iodide, methanesulfonate, p-toluenesulfonate, or benzene sulfonate;
- the solvent is heptane, octane, toluene, xylene, methyl isobutyl ketone, methyl isoamyl ketone or a mixture thereof;
- and the catalyst is tetrabutylammonium bromide or tetrabutylphosphonium bromide.
Dependencies are inferred from the claim text.