Preparation method of glufosinate or derivatives thereof

A method for preparing glufosinate of formula (I) or a compound of formula (I)-1, or a salt, an enantiomer thereof or a mixture of the enantiomers in all ratios, wherein the method comprises the following steps:

• or
• a) reacting a compound of formula (II) or a salt, an enantiomer thereof or a mixture of the enantiomers in all ratios with a compound of formula (III), wherein the compound of formula (III) is the only phosphorus-containing reaction starting material;
• when the method is for preparing glufosinate of formula (I), the method further comprises step b) reacting the intermediate, no matter whether it is isolated or not, in the presence of water and an acid or a base to obtain the glufosinate (1) or a salt, an enantiomer thereof or a mixture of the enantiomers in all ratios;
• when the method is for preparing a compound of formula (I)-1, the method further comprises step b-1) reacting the intermediate, no matter whether it is isolated or not, in the presence of R8OH, to obtain the compound of formula (I)-1 or a salt, an enantiomer thereof or a mixture of the enantiomers in all ratios;
• when PG is an amino protecting group, a step of removing the amino protecting group can be further comprised;
• wherein:
• X is halogen, —OAc, —OTs, —OMs or
• Hal, Hal1 and Hal2 are each independently halogen selected from fluorine, chlorine, bromine or iodine;
• Y is —OR1, —NH2, —NHR2 or —N(R2)(R3);
• PG is hydrogen or an amino protecting group selected from —C(═O)R4, —C(═O)OR4 or —S(═O)2R4;
• R1, R2 and R3 are each independently hydrogen, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-10 cycloalkyl, C6-10 aryl, C6-12 aralkyl, 5-14-membered heteroaryl, 3-10-membered heterocyclyl or —Si(R5)(R6)(R7);
• R4 is selected from the group consisting of C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-10 cycloalkyl, C6-10 aryl, C6-12 aralkyl, 5-14-membered heteroaryl and 3-10-membered heterocyclyl;
• R5, R6 and R7 are each independently hydrogen, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-10 cycloalkyl, C6-10 aryl, C6-12 aralkyl, 5-14-membered heteroaryl or 3-10-membered heterocyclyl;
• R8 is H, C1-C6 alkyl, C3-10 cycloalkyl, C6-10 aryl, C6-12 aralkyl, 5-14-membered heteroaryl or 3-10-membered heterocyclyl;
• the above alkyl, alkenyl, alkynyl, cycloalkyl, aryl, aralkyl, heteroaryl and heterocyclyl are each optionally substituted by one or more substituents independently selected from the group consisting of:
• halogen, —OH, ═O, —O—(C1-C6 alkyl), —C(═O)—(C1-C6 alkyl), —C(═O)OH, —C(═O)O—(C1-C6 alkyl), —NH2, —NO2, —CN, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-10 cycloalkyl, C6-10 aryl, C6-12 aralkyl, 5-14-membered heteroaryl and 3-10-membered heterocyclyl;
• the chiral carbon atom is labeled with *.