US 11,680,077 B2
Preparation method for glufosinate
Yongjiang Liu, Sichuan (CN); Lei Zhou, Sichuan (CN); Wei Zeng, Sichuan (CN); Min Xu, Sichuan (CN); Ke Cheng, Sichuan (CN); and Yingsui Yin, Sichuan (CN)
Assigned to LIER CHEMICAL CO., LTD., Sichuan (CN); and GUANGAN LIER CHEMICAL CO., LTD., Sichuan (CN)
Appl. No. 17/610,051
Filed by LIER CHEMICAL CO., LTD., Sichuan (CN); and GUANGAN LIER CHEMICAL CO., LTD., Sichuan (CN)
PCT Filed Jan. 20, 2021, PCT No. PCT/CN2021/072854
§ 371(c)(1), (2) Date Nov. 9, 2021,
PCT Pub. No. WO2021/147894, PCT Pub. Date Jul. 29, 2021.
Claims priority of application No. 202010064268.7 (CN), filed on Jan. 20, 2020.
Prior Publication US 2022/0259232 A1, Aug. 18, 2022
Int. Cl. C07F 9/30 (2006.01)
CPC C07F 9/301 (2013.01) 31 Claims
 
1. A method for preparing glufosinate of formula (I);

OG Complex Work Unit Chemistry
or a salt, an enantiomer or a mixture of enantiomers thereof, the method comprising steps of:
a) reacting a compound of formula (II):

OG Complex Work Unit Chemistry
or a salt, an enantiomer or a mixture of enantiomers thereof,
with one or more compounds of formula (III) or a mixture to form an intermediate, the mixture comprising:
one or more compounds of the formula (IV) and one or more compounds of formula (V);
one or more compounds of the formula (IV) and one or more compounds of the formula (III);
one or more compounds of formula (V) and one or more compounds of the formula (III); or
one or more compounds of the formula (III), one or more compounds of the formula (IV) and one or more compounds of the formula (V)

OG Complex Work Unit Chemistry
b) reacting the intermediate, isolated or not isolated, in the presence of water and an acid or a base to obtain the glufosinate of the formula (I) or the salt, the enantiomer or the mixture of enantiomers thereof,
wherein when PG is an amino protecting group, the method further comprises a step of removing the amino protecting group, and
wherein:
Hal1 and Hal2 are each independently halogen;
PG is hydrogen or an amino protecting group;
R1, R2, R3 and R4 are each independently alkyl, phenyl or substituted phenyl, and when the mixture comprises one or more compounds of the formula (IV) and one or more compounds of the formula (III), or when the mixture comprises one or more compounds of the formula (III), one or more compounds of the formula (IV) and one or more compounds of the formula (V), R2 is either R3 or R4; and
the chiral carbon atom is labeled with *.