US 12,145,957 B2
Preparation method for glufosinate
Yongjiang Liu, Sichuan (CN); Lei Zhou, Sichuan (CN); Wei Zeng, Sichuan (CN); Min Xu, Sichuan (CN); and Ke Cheng, Sichuan (CN)
Assigned to LIER CHEMICAL CO., LTD., Mianyang (CN)
Filed by LIER CHEMICAL CO., LTD., Sichuan (CN)
Filed on Apr. 20, 2023, as Appl. No. 18/303,613.
Application 18/303,613 is a continuation of application No. PCT/CN2022/106398, filed on Jul. 19, 2022.
Claims priority of application No. 202110817019.5 (CN), filed on Jul. 20, 2021.
Prior Publication US 2023/0331750 A1, Oct. 19, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. C07F 9/54 (2006.01); C07C 237/06 (2006.01); C07C 323/32 (2006.01); C07C 323/59 (2006.01)
CPC C07F 9/5407 (2013.01) [C07C 237/06 (2013.01); C07C 323/32 (2013.01); C07C 323/59 (2013.01)] 30 Claims
 
1. A method for preparing a glufosinate compound of formula (I), a salt thereof, an enantiomer thereof, or a mixture of enantiomers thereof, which enantiomers may be present in any ratio,
wherein the method comprises the following steps:

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a) reacting a compound of formula (II) or a salt thereof, an enantiomer thereof or a mixture of enantiomers thereof, which enantiomers may be present in any ratio,

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with one or more compounds of formula (III) or a mixture; wherein said mixture comprises one or more compounds of formula (IV) and one or more compounds of formula (V); or one or more compounds of formula (IV) and one or more compounds of formula (III); or one or more compounds of formula (V) and one or more compounds of formula (III); or one or more compounds of formula (III), one or more compounds of formula (IV), and one or more compounds of formula (V),
wherein the reaction of a) results in a “reaction intermediate”;

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b) reacting the reaction intermediate which results from step a), wherein said reaction intermediate may or may not be in isolated form, with an acid or a base to obtain a glufosinate compound of formula (I) or a salt thereof, an enantiomer thereof, or a mixture of enantiomers thereof, which enantiomers may be present in any ratio;
wherein when PG is an amino protecting group, the method further optionally includes the removal of the amino protecting group;
further wherein:
LG is Hal1, —OTs or Hal1

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Hal1 and Hal2 are each independently halogen selected from fluorine, chlorine, bromine or iodine;
PG is hydrogen or an amino protecting group selected from —C(═O)R, —C(═O)OR and —S(═O)2R;
A is —NHR1, —NR1R1′, or —OR1;
R, R1, R1′, R2, R3 and R4 are each independently selected from the group consisting of C1-C6 alkyl, C3-10 cycloalkyl, C6-10 aryl, C6-12 aralkyl, 5- to 14-membered heteroaryl and 3- to 10-membered heterocyclyl,
with the further proviso that when the mixture comprises a mixture of one or more compounds of formula (IV) and one or more compounds of formula (III); or a mixture of one or more compounds of formula (III), one or more compounds of formula (IV) and one or more compounds of formula (V); then
R2 is either R3 or R4; and
the chiral carbon atom is labeled with *; and
with the further proviso that at least one of the following conditions is met:
1) the compound of formula (II) is not

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2) the compound of formula (III) is not

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3) the compound of formula (IV) is not

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4) the compound of formula (V) is not

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