- Grass ammonium phosphine method for the preparation of
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The invention belongs to the field of chemical synthesis, and particularly relates to a new preparation method of a glufosinate-ammonium weed killer. The preparation method is characterized in that methyl phosphorus dichloride reacts with alcohol so as to prepare a methyl phosphonate compound IV, and then the methyl phosphonate compound IV reacts with acrolein so as to prepare a methyl propionaldehyde phosphonate compound II; the methyl propionaldehyde phosphonate compound II is subjected to Bucherer-Bergs ring-closure reaction so as to prepare a hydantoin derivative shown in a formula III, and the hydantoin derivative is subjected to hydrolysis reaction so as to prepare the glufosinate-ammonium compound shown in a formula I. The preparation method of the glufosinate-ammonium has the advantages that required conditions are mild, the detection is easy, the required raw materials are easily available and low in cost, the yield of the obtained product is high, the obtained product has high purity, and ammonium salt is removed without needing recrystallization over and over again.
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Paragraph 0072; 0075; 0076
(2017/01/17)
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- A kind of preparation method for treating keratoconjunctival
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The invention belongs to the field of chemical synthesis, and in particular relates to a novel method for preparing herbicide, namely glufosinate-ammonium. The method comprises the following steps: conducting addition reaction on methyl phosphonic acid ester compounds and DL-2-hydroxy-3-crotonic acid ester compounds to obtain hydroxybutyric acid ester derivatives, and conducting acidification and ammonification reaction on the hydroxybutyric acid ester derivatives to obtain a glufosinate-ammonium compound. The method can avoid using high-toxic cyanide and obviously shortens a reaction route, so that the reaction steps of a process for preparing glufosinate-ammonium are reduced, the operation is simpler and more convenient, and many times of recrystallization is not needed for removing ammonium salt. The cost is reduced, and the method is completely suitable for large-scale production.
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Paragraph 0037; 0038
(2017/01/12)
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- Phosphinic acid analogues of GABA. 2. Selective, orally active GABA(B) antagonists
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In 1987, 25 years after the synthesis of the potent and selective GABA(B) agonist baclofen (1), Kerr et al. described the first GABA(B) antagonist phaclofen 2. However, phaclofen and structurally similar derivatives 3-5 did not cross the blood-brain barrier and hence were inactive in vivo as central nervous system agents. As a consequence, the therapeutic potential of GABA(B) antagonists remained unclear. In exploring GABA and baclofen derivatives by replacing the carboxylic acid residue with various phosphinic acid groups, we discovered more potent and water soluble GABA(B) antagonists. Electrophysiological experiments in vivo demonstrated that some of the new compounds were capable of penetrating the blood-brain barrier after oral administration. Neurotransmitter release experiments showed that they interacted with several presynaptic GABA(B) receptor subtypes, enhancing the release of GABA, glutamate, aspartate, and somatostatin. The new GABA(B) antagonists interacted also with postsynaptic GABA(B) receptors, as they blocked late inhibitory postsynaptic potentials. They facilitated the induction of long-term potentiation in vitro and in vivo, suggesting potential cognition enhancing effects. Fifteen compounds were investigated in various memory and learning paradigms in rodents. Although several compounds were found to be active, only 10 reversed the age-related deficits of old rats in a multiple-trial one-way active avoidance test after chronic treatment. The cognition facilitating effects of 10 were confirmed in learning experiments in Rhesus monkeys. The novel GABA(B) antagonists showed also protective effects in various animal models of absence epilepsy.
- Froestl,Mickel,Von Sprecher,Diel,Hall,Maier,Strub,Melillo,Baumann,Bernasconi,Gentsch,Hauser,Jaekel,Karlsson,Klebs,Maitre,Marescaux,Pozza,Schmutz,et al.
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p. 3313 - 3331
(2007/10/02)
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