81228-02-6Relevant articles and documents
Novel route for preparing dolutegravir key intermediate 2,4-difluorobenzylamine
-
Paragraph 0025, (2018/11/22)
The invention discloses a production route which is concise and green in route, low in cost and easy to industrialize to prepare 2,4-difluorobenzylamine. The route comprises the following four steps:a) by taking m-difluorobenzene as an initial raw material, under catalysis of lewis acid, carrying out a Foucault alkylation reaction with ethylene oxide so as to prepare an intermediate 2,4-difluorobenzene ethanol; b) carrying out a second step of reactions on the product of the step a) without separation or purification, and oxidizing the 2,4-difluorobenzene ethanol to generate 2,4-difluorobenzene phenylacetic acid; c) enabling the product 2,4-difluorobenzene phenylacetic acid of the step b) with sulfoxide chloride and an ammonia gas to react so as to prepare 2,4-difluorophenylacetamide; d)under induction of bromine, enabling the product 2,4-difluorophenylacetamide of the step c) to react with a sodium hypochlorite solution, and carrying out Hofmann degradation, thereby obtaining a target product 2,4-difluorobenzylamine. The preparation method disclosed by the invention is simple and easy in raw material obtaining, concise in route, green and environmentally friendly, low in cost and easy in industrial production.
2-substituted (2SR)-2-amino-2-((1SR,2SR)-2-carboxycycloprop-1- yl)glycines as potent and selective antagonists of group II metabotropic glutamate receptors. 2. Effects of aromatic substitution, pharmacological characterization, and bioavailability
Ornstein, Paul L.,Bleisch, Thomas J.,Arnold, M. Brian,Kennedy, Joseph H.,Wright, Rebecca A.,Johnson, Bryan G.,Tizzano, Joseph P.,Helton, David R.,Kallman, Mary Jeanne,Schoepp, Darryle D.,Hérin, Marc
, p. 358 - 378 (2007/10/03)
In this paper we describe the synthesis of a series of α-substituted analogues of the potent and selective group II metabotropic glutamate receptor (mGluR) agonist (1S,1'S,2'S)-carboxycyclopropylglycine (2, L-CCG 1). Incorporation of a substituent on the amino acid carbon converted the agonist 2 into an antagonist. All of the compounds were prepared and tested as a series of four isomers, i.e., two racemic diastereomers. On the basis of the improvement in affinity realized for the α-phenylethyl analogue 3, in this paper we explored the effects of substitution on the aromatic ring as a strategy to increase the affinity of these compounds for group II mGluRs. Affinity for group II mGluRs was measured using [3H]glutamic acid (Glu) binding in rat forebrain membranes. Antagonist activity was confirmed for these compounds by measuring their ability to antagonize (1S,3R)-1- aminocyclopentane-1,3-dicarboxylic acid-induced inhibition of forskolin stimulated cyclic-AMP in RGT cells transfected with human mGluR2 and mGluR3. Meta substitution on the aromatic ring of 3 with a variety of substituents, both electron donating (e.g., methyl, hydroxy, amino, methoxy, phenyl, phenoxy) and electron withdrawing (e.g., fluorine, chlorine, bromine, carboxy, trifluoromethyl) gave from 1.5- to 4.5-fold increases in affinity. Substitution with p-fluorine, as in 97 (IC50 = 0.022 ± 0.002), was the exception. Here, a greater increase in affinity was realized than for either the ortho- or meta-substituted analogues; 97 was the most potent compound resulting from monosubstitution of the aromatic. At best, only modest increases in affinity were realized for certain compounds bearing either two chlorines or two fluorines, and two methoxy groups gave no improvement in affinity (all examined in a variety of substitution patterns). Three amino acids, 4, 5, and 104, were resolved into their four constituent isomers, and affinity and functional activity for group II mGluRs was found to reside solely in the S,S,S-isomers of each, consistent with 1. With an IC50 = 2.9 ± 0.6 nM, the resolved xanthylmethyl compound 168 was the most potent compound from this SAR. Amino acid 168 demonstrated high plasma levels following intraperitoneal (ip) administration and readily penetrated into the brain. This compound, however, had only limited (~5%) oral bioavailability. Systemic administration of 168 protected mice from limbic seizures produced by the mGluR agonist 3,5-dihydroxyphenylglycine, with an ED50 = 31 mg/kg (ip, 60 min preinjection). Thus, 168 represents a valuable tool to study the role of group II mGluRs in disease.
