L-glufosinate ammonium preparation method

Abstract

The invention discloses a method for obtaining L-glufosinate ammonium with single configuration by catalytically hydrolyzing an inexpensive and easily-available glufosinate ammonium cyanamide intermediate with biological enzyme through a one-pot method, wherein the hydrolyzing process specifically comprises: 1, obtaining a glufosinate ammonium amide racemate from a racemic glufosinate ammonium cyanamide intermediate under the action of non-selective nitrile hydratase; 2, selectively hydrolyzing the L-glufosinate ammonium amide intermediate with L-amide hydrolase to obtain L-glufosinate ammonium phosphonate while racemizing the unhydrolyzed D-glufosinate ammonium amide intermediate under the action of ACL racemase to continuously convert into the L-glufosinate ammonium amide intermediate, such that the single L-glufosinate ammonium phosphonate is finally obtained through the DKR process; and 3, hydrolyzing the L-glufosinate ammonium phosphonate under the action of dilute hydrochloric acid to obtain the L-glufosinate ammonium.

Description

technical field [0001] The invention belongs to the technical fields of biopharmaceutical and biochemical industry, and in particular relates to a preparation method of L-glufosinate. Background technique [0002] Glufosinate-ammonium was successfully developed by Hearst in the 1980s. It is a phosphonic acid herbicide, an inhibitor of glutamine synthesis, and a contact-killing herbicide. It is a broad-spectrum, low-toxic, non-selective herbicide. It is also the second most herbicide-tolerant genetically modified crops in the world, and its application prospects are very broad. [0003] At present, glufosinate-ammonium sold in the market is generally a racemic mixture. If the glufosinate-ammonium product can be used with the pure optical isomer of L-configuration (structural formula ), which can reduce the consumption of glufosinate-ammonium by 50%, which is of great significance for improving atom economy, reducing use cost and alleviating environmental pressure. [0004...

AI Technical Summary

Problems solved by technology

[0014] There are following disadvantages in this method: some intermediates are very water-soluble, difficult to separate and purify; the asymmetric reduction of double bonds needs to use expensive noble metals and ligands, which is uneconomical; the enantioselectivity of the product is low (only 84% ee), the total yield of the reaction is low (only 26.7%)

[0017] This method has the following disadvantages: the substrate is difficult to synthesize, the reaction needs multiple cofactors such as transaminase, coenzyme and amine donor, and there is no advantage in cost

[0024] This method needs to use expensive methionine as a starting material, and the reaction synthesis route is long, the total yield is relatively low, the cost is high, and there is no industrial application prospect

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