- Method for synthesizing benserazide hydrochloride by utilizing fixed bed hydrogenation equipment
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The invention discloses a method for synthesizing benserazide hydrochloride by using fixed bed hydrogenation equipment, which is characterized in that a compound 1 reacts with an amino protective agent to carry out an amino protection reaction, so that the subsequent purification is easy, and the dosage of hydrazine hydrate in the synthesis method is small; according to the method, fixed bed hydrogenation equipment is used for synthesis, a fixed bed reactor is filled with a solid catalyst or a solid to realize a heterogeneous reaction process, the catalyst in the fixed bed reactor is relatively fixed, a reaction liquid flows through a bed layer, and the reaction liquid flows through the bed layer by adjusting the flow rate and the reaction pressure; qualified products can be obtained after reaction liquid flows out of the fixed bed, continuous production can be achieved, product deterioration caused by long-time contact of the products and the catalyst can be avoided, the same amount of products can be produced due to continuous production, the reactor size can be very small, the safety problem caused by high-pressure reaction is greatly reduced, the amount of the catalyst used in the reaction is less, and the production cost is reduced.
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Paragraph 0040; 0046-0047
(2021/06/02)
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- Efficient Synthesis of N-Sulfonyl β -Arylmethylalaninates from Serine via Ring Opening of N-Sulfonyl Aziridine-2-carboxylate
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We report the efficient synthesis of N-sulfonyl β-arylalanines methyl ester through regioselective ring opening of N-protected aziridines by variety of heteroaryl C-nucleophiles. We have optimized synthesis of N-protected aziridines with versatile protecting groups to afford 4a-c, 6a, and 6b with moderate to good yields using sulfuryl chloride, triethyl amine, and toluene at -50 °C. The present work reports on the studies related to electronic effect of nitrogen substituent on aziridination from the inexpensive starting material DL-serine. The present investigation also reports the efficient synthesis of N-sulfonyl β-arylmethylalaninates (7a-e and 8a-e) by regioselective nucleophilic ring opening of N-sulfonamido-protected aziridines using various aryl moieties such as C-nucleophiles and Lewis acids (InCl3, FeCl3, Cu(OTf)2) as catalysts and some trials by ring opening using Grignard reagent. GRAPHICAL ABSTRACT.
- Chaudhari, Prashant,Bari, Sanjay
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supporting information
p. 401 - 412
(2015/10/29)
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- An innovative strategy for the synthesis of a new series of potent aminopeptidase (APN or CD13) inhibitors derived from the oxepin-4-one family
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Derivatives from the aminobenzosuberone family have been recently synthesized and recognized as highly selective inhibitors of aminopeptidase N (APN)/CD13 (EC 3.4.11.2), an important target for cell migration processes involved in particular in tumor inva
- Roux, Lionel,Charrier, Cédric,Salomon, Emmanuel,Ilhan, Meral,Bisseret, Philippe,Tarnus, Céline
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scheme or table
p. 2586 - 2589
(2011/06/21)
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- Primary amino acid derivatives: Compounds with anticonvulsant and neuropathic pain protection activities
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Pharmacological management remains the primary method to treat epilepsy and neuropathic pain. We have advanced a novel class of anticonvulsants termed functionalized amino acids (FAAs). In this study, we examine FAA derivatives from which the terminal acetyl moiety was removed and termed these compounds primary amino acid derivatives (PAADs). Twenty-seven PAADs were prepared; the central C(2) R-substituent was varied, including C(2) stereochemistry, and the compounds were tested in rodent models of seizures and neuropathic pain. C(2)-Hydrocarbon N-benzylamide PAADs were potent anticonvulsants and excellent anticonvulsant activity (mice, ip; rat, po) was observed for C(2) R-substituted PAADs in which the R group was ethyl, isopropyl, or tert-butyl, and the C(2) stereochemistry conformed to the d-amino acid configuration ((R)-stereoisomer). These values surpassed the activities of several clinical antiepileptic drugs. The C(2) (R)-ethyl and C(2) (R)-isopropyl PAADs also displayed excellent activities in the mouse (ip) formalin neuropathic pain model. Significantly, unlike the FAA structure-activity relationship, PAAD anticonvulsant activity increased upon substitution of a methylene unit for a heteroatom in the R-substituent that was one atom removed from the C(2) site, suggesting that these PAADs function by a different pathway than FAAs.
- King, Amber M.,Salomé, Christophe,Dinsmore, Jason,Salomé-Grosjean, Elise,De Ryck, Marc,Kaminski, Rafal,Valade, Anne,Kohn, Harold
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supporting information; experimental part
p. 4815 - 4830
(2011/10/01)
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- NOVEL INHIBITORS OF POLY(ADP-RIBOSE)POLYMERASE (PARP)
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A compound having the structure set forth in Formula (I): wherein the variables Y, R1, R2, R3, R4 and R5 are as defined herein. Compounds described herein are inhibitors of poly(ADP-ribose)polymerase activity. Also described herein are pharmaceutical compositions that include at least one compound described herein and the use of such compounds and pharmaceutical compositions to treat diseases, disorders and conditions that are ameliorated by the inhibition of PARP activity
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Page/Page column 45
(2009/04/24)
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- Access to enantioenriched α-amino esters via rhodium-catalyzed 1,4-addition/enantioselective protonation
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Conjugate addition of potassium trifluoro(organo)borates 2 to dehydroalanine derivatives 1, mediated by a chiral rhodium catalyst and in situ enantioselective protonation, afforded straightforward access to a variety of protected α-amino esters 3 with high yields and enantiomeric excesses up to 95%. Among the tested chiral ligands and proton sources, Binap, in combination with guaiacol (2-methoxyphenol), an inexpensive and nontoxic phenol, afforded the highest asymmetric inductions. Organostannanes have also shown to participate in this reaction. By a fine-tuning of the ester moiety, and using Difluorophos as chiral ligand, increased levels of enantioselectivity, generally close to 95%, were achieved. Deuterium labeling experiments revealed, and DFT calculation supported, an unusual mechanism involving a hydride transfer from the amido substituent to the α carbon explaining the high levels of enantioselectivity attained in controlling this α chiral center.
- Navarre, Laure,Martinez, Remi,Genet, Jean-Pierre,Darses, Sylvain
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p. 6159 - 6169
(2008/12/20)
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- N-Methyl-N-(o-nitrophenyl)carbamates as photolabile alcohol protecting groups
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N-Methyl-N-(o-nitrophenyl)carbamates represent new photoremovable alcohol protecting groups. This protecting group is easily incorporated by chemical coupling of the corresponding alcohol to N-methyl-N-(o-nitrophenyl)carbamoyl chloride. High yield and clean deprotection are induced by photolysis in protic solvents (water, ethanol or ethanol/water mixtures) from 254 to 365 nm.
- Loudwig, Sandra,Goeldner, Maurice
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p. 7957 - 7959
(2007/10/03)
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- A facile and chemoselective cleavage of trityl ethers by indium tribromide
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Trityl ethers are chemoselectively, deprotected to the corresponding alcohols in high yields by a catalytic amount of indium tribromide in aqueous acetonitrile. The method is compatible with various functional groups such as acetonides, acetates, benzoates, olefins, carbamates, esters and ethers present in the substrate.
- Yadav,Reddy, B.V. Subba,Srinivas,Maiti
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p. 528 - 529
(2007/10/03)
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- Selective deprotection of tetrahydropyranyl ethers catalysed by β-cyclodextrin in water
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The hydrolysis of tetrahydropyranyl ethers to alcohols catalysed by β-cyclodextrin proceeds in water under neutral conditions.
- Arjun Reddy,Rajender Reddy,Bhanumathi,Rama Rao
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p. 359 - 360
(2007/10/03)
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- A mild and selective cleavage of trityl ethers by CBr4-MeOH
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Trityl ethers are selectively deprotected to the corresponding alcohols in high yields by CBr4 in refluxing methanol under neutral reaction conditions. Other hydroxyl protecting groups like isopropylidene, allyl, benzyl, acetyl, benzoyl, methyl
- Yadav, Jhillu S.,Subba Reddy, Basi V.
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p. 885 - 888
(2007/10/03)
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- A mild and selective cleavage of tert-butyldimethylsilyl ethers by indium(III) chloride
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Alkyl tert-butyldimethylsilyl ethers are selectively deprotected to the corresponding alcohols in high yields for the first time by indium(III) chloride in refiuxing aqueous acetonitrile. Several functional groups like OBn, Boc, CBz, OBz, O-allyl, OTBDPS, OAc, OMe, ethers, esters and olefins present in the substrate are unaffected.
- Yadav,Subba Reddy,Madan
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p. 853 - 854
(2007/10/03)
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- Structure-binding relation of philanthotoxins from nicotinic acetylcholine receptor binding assay
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Philanthotoxins are noncompetitive inhibitors of the nicotinic acetylcholine receptor and the various glutamate receptors. Analogues carrying photoaffinity labels, fluorine atoms for solid-state NMR studies of ligand/receptor interaction, and large head g
- Nakanishi, Koji,Huang, Xuefei,Jiang, Hong,Ying, Liu,Fang, Kan,Huang, Danwen,Choi, Seok-Ki,Katz, Elizabeth,Eldefrawi, Mohyee
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p. 1969 - 1988
(2007/10/03)
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- Amino-acids and peptides. Part VI. The synthesis, by twinning, of cyclodepsipeptides related to serratamolide
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A fourteen-membered cyclodepsipeptide has been synthesised by the interaction of two molecules of β-L-leucyloxy-propionyl chloride. A similar synthesis utilising β-(O-t-butyl-DL-seryloxy)propionyl chloride gave two isomers. The relationship of these isomers has been discussed.
- Hassall,Martin,Schofield,Thomas, Jean O.
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p. 997 - 1003
(2007/10/10)
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