US 6,552,217 B2 · Process for the preparation of alkyl 1-methylcyclopropanecarboxylate

Abstract

Disclosed is a 4-step process for the preparation of alkyl esters of 1-methylcyclopropanecarboxylic acid which comprises the steps of (1) converting γ-butyrolactone to α-methyl-γ-butyrolactone; (2) converting the α-methyl-γ-butyrolactone from step (1) to an alkyl 4-halo-2-methylbutyrate; (3) producing a xylene solution of the alkyl 4-halo-2-methylbutyrate; and (4) contacting the xylene solution of an alkyl 4-halo-2-methylbutyrate from step (3) with an alkali metal alkoxide under conditions of temperature and pressure which causes vaporization of (i) an alkanol as it is formed and (ii) an alkyl 1-methylcyclopropanecarboxylate as it is formed from the alkyl 4-halo-2-methylbutyrate. Also disclosed are processes whereby the alkyl 1-methylcyclopropanecarboxylate, prepared as described above, is converted to 1-methylcyclopropylamine.

Claims10

Dependent claims

Process for the preparation of alkyl 1-methylcyclopropanecarboxylate which comprises the steps of:

(1) contacting γ-butyrolactone with dimethylcarbonate in the presence of a basic catalyst to produce α-methyl-γ-butyrolactone;
(2) contacting the α-methyl-γ-butyrolactone from step (1) with a hydrogen halide in the presence of an alkanol, wherein said alkanol is methanol or ethanol, to produce a reaction mixture containing an alkyl 4-halo-2-methylbutyrate;
(3) contacting the reaction mixture of step (2) with xylene to produce a xylene solution of an alkyl 4-halo-2-methylbutyrate;
(4) contacting the xylene solution of an alkyl 4-halo-2-methylbutyrate from step (3) with an alkali metal alkoxide under conditions of temperature and pressure which causes vaporization of (i) an alkanol as it is formed and (ii) an alkyl 1-methylcyclopropanecarboxylate as it is formed from the alkyl 4-halo-2-methylbutyrate.

1 more element

Dependencies are inferred from the claim text.

Process for the preparation of alkyl 1-methylcyclopropanecarboxylate

Life of this patent

Process for the preparation of alkyl 1-methylcyclopropanecarboxylate

Life of this patent

Abstract

Claims10