- Preparation method of 2,4,5-trifluorophenylacetic acid
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The invention belongs to the technical field of preparation of drug intermediates, and discloses a preparation method of 2,4,5-trifluorophenylacetic acid, wherein the preparation method comprises the steps: step 1, reacting raw materials, a quaternary ammonium salt catalyst, sulfolane and potassium fluoride to obtain a first intermediate; step 2, carrying out hydrogenation catalytic reaction on the first intermediate to obtain a second intermediate; step 3, carrying out salt forming reaction on the second intermediate and a fluorinating reagent, quenching, and carrying out diazotization reaction on the second intermediate and a sodium nitrite aqueous solution to obtain diazonium salt; step 4, carrying out high-temperature cracking on the diazonium salt, to obtain 2,4,5-trifluorotoluene; and step 5 to step 7, carrying out halogenation, cyanidation and hydrolysis reactions on 2,4,5-trifluorotoluene in sequence, and thus obtaining 2,4,5-trifluorophenylacetic acid. The raw materials adopted by the method are easy to obtain and low in cost, the yield of the corresponding product obtained in each step is high, and large-scale production of the 2,4,5-trifluorophenylacetic acid is facilitated.
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Paragraph 0040-0041; 0051; 0083
(2021/05/29)
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- Preparation of a first 18F-labeled agonist for M1 muscarinic acetylcholine receptors
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M1 muscarinic acetylcholine receptors (mAChRs) are abundant in postsynaptic nerve terminals of all forebrain regions and have been implicated in the cognitive decline associated with Alzheimer’s disease and other CNS pathologies. Consequently,
- Drewes, Birte,Kolks, Niklas,Neumaier, Bernd,Neumaier, Felix,Rüngeler, Till,Zlatopolskiy, Boris D.
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- 1-(1-CYCLOBUTYL-4-PIPERIDINYL)-1,3-DIHYDRO-2H-BENZIMIDAZOL-2-ONE DERIVATIVES WHICH HAVE ACTIVITY ON THE ML RECEPTOR AND THEIR USE IN MEDICINE
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Compounds of formula I or a salt thereof are provided wherein R4, R5, R6, Q, L and R are as defined in the description. Uses of the compounds as medicaments and in the manufacture of medicaments for treating psychotic disorders and cognitive impairments are disclosed. The invention further discloses pharmaceutical compositions comprising the compounds.
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Page/Page column 54
(2008/12/04)
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- 1- (1-CYCLOHEXYL-4-PIPERIDINYL) -1, 3-DIHYDRO-2H-BENZIMIDAZOL-2-ONE DERIVATIVES WHICH HAVE ACTIVITY ON THE M1 RECEPTOR AND THEIR USE IN MEDICINE
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Compounds of formula (I) or a salt thereof are provided, wherein R4, R5, R6, Q and R are as defined in the description. Uses of the compounds as medicaments and in the manufacture of medicaments for treating psychotic disorders and cognitive impairments are disclosed. The invention further discloses pharmaceutical compositions comprising the compounds.
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Page/Page column 63
(2008/12/04)
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- Alkyl, azido, alkoxy, and fluoro-substituted and fused quinoxalinediones
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Methods of treating or preventing neuronal loss associated with stroke, ischemia, CNS trauma, hypoglycemia, and surgery, as well as treating neurodegenerative diseases including Alzheimer's disease, amyotrophic lateral sclerosis, Huntington's disease, and Down's syndrome, treating or preventing the adverse consequences of the hyperactivity of the excitatory amino acids, as well as treating anxiety, chronic pain, convulsions, and inducing anesthesia are disclosed by administering to an animal in need of such treatment an alkyl or azido-substituted 1,4-dihydroquinoxaline-2,3-dione or pharmaceutically acceptable salts thereof, which have high binding to the glycine receptor.
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- Regiospecific Oxidative Nitration of 3,4-Dihydro-6,7-disubstituted Quinoxalin-2(1H)-ones Gives 1,4-Dihydro-5-nitro-6,7-disubstituted Quinoxaline-2,3-diones, Potent Antagonists at the NMDA/Glycine Site
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The regiospecific oxidative nitration of 3,4-dihydro-6,7-disubstituted quinoxalin-2(1H)-ones (15a-h, 20) utilizing fuming nitric acid in TFA gave 1,4-dihydro-5-nitro-6,7-disubstituted quinoxaline-2,3-diones (6a-i), respectively, in good yields.Compounds 15a-h were prepared from commercially available 1-halo-3,4-disubstituted benzenes 12a-h in three steps.These were nitration, nucleophilic substitution of the halogen ortho to the nitro group with sodium glycinate, and finally, reduction of the nitro group and concomitant cyclization.Compound 20 was prepared from 16 by a different route involving alkylation of substituted o-nitroaniline 18.The final oxidative nitration yields a single, predictable nitro isomer and is a significant improvement over the direct nitration of 6,7-disubstituted quinoxaline-2,3-diones.
- Kher, Sunil M.,Cai, Sui Xiong,Weber, Eckard,Keana, John F. W.
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p. 5838 - 5842
(2007/10/03)
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- Quinazoline antifolate thymidylate synthase inhibitors: Difluoro- substituted benzene ring analogues
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The synthesis of a series of new C2-methyl-N10-alkylquinazoline-based thymidylate synthase (TS) inhibitors containing difluorinated p-aminobenzoate rings is described. Derivatives of the N10-propargyl and N10- m
- Thornton,Jackman,Marsham,O'Connor,Bishop,Calvert
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p. 2321 - 2327
(2007/10/02)
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