US 11,466,041 B2 · Process for preparing methyl phosphinic acid butyl ester

Abstract

The present subject matter provides a safe alternative for producing an important intermediate useful for preparing the herbicide glufosinate, without need for chlorine components in the manufacturing process. In particular, a process for preparing alkyl phosphinic aid alkyl ester is provided, including the step of alkylating alkyl phosphinic acid ester in a non-polar solvent in the same apparatus as used to first produce the alkyl phosphinic acid ester, and without isolating the alkyl phosphinic acid ester before the alkylation step is conducted. More specifically, a process is presented for preparing methyl phosphinic acid butyl ester, by alkylating butyl phosphinic acid ester in a non-polar solvent, in the same apparatus as used previously to first produce the butyl phosphinic acid ester and without isolating the butylphosphinic acid ester before alkylation.

Claims15

Dependent claims

A process for preparing the compound of the formula (II)

wherein R is a C1-C6 alkyl or benzyl, and R1 is C1-C6 alkyl, by an alkylation reaction comprising reacting in a non-polar solvent the compound of formula (I)
wherein R is C1-C6 alkyl or benzyl,
with an alkylating agent in the presence of a base;
wherein the compound of formula (I) was prepared in the same non-polar solvent and without being isolated from the non-polar solvent prior to reacting with the alkylating agent in the presence of the base,
wherein the non-polar solvent is one or more of toluene, cyclohexane, xylene, benzene, methyl ethyl ketone, and methyl isobutyl ketone (MIBK);
and
wherein the base is one or more of sodium metal, NaOH, K2CO3, MeONa/MeOH (30% solution), 4-dimethylaminopyridine, diazabicyclo[2.2.2]octane, potassium tert-butoxide, sodium tert-butoxide, Pyridine, 2-Picoline, Et3N, i-Pr2Net, alkyl-OMetal (Metal alkoxide), KH, Alkyl MgX (Grignard reagent), NaNH2, lithium diisopropylamide (LDA), sodium methoxide;
sodium hydride and diisobutyl amide salt.

5 more elements

Dependencies are inferred from the claim text.

Process for preparing methyl phosphinic acid butyl ester

Life of this patent

Process for preparing methyl phosphinic acid butyl ester

Life of this patent

Abstract

Claims15