- Solvent-free, base-free microwave-mediated iridium-catalyzed N-alkylation of amides with alcohols
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Solvent-free, base-free microwave-mediated (CpIrCl2) 2-catalyzed conditions for the N-alkylation of amides with alcohols have been developed. A series of primary and secondary alcohols have been shown to produce high yields of N-alkyl arylamides and N-alkyl alkylamides.
- Apsunde, Tushar D.,Trudell, Mark L.
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p. 230 - 234
(2014/03/21)
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- Acetic anhydride induced rearrangement and Grignard addition on C-phenyl-N-(1-methyl-2-aryl)ethyl nitrones
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This article describes the acetic anhydride induced rearrangement of nitrone to amide and the addition of Grignard reagent to the nitrones yielding substituted hydroxylamines. It has been found that the conversion of C-phenyl-N-(1-methyl- 2-aryl)ethyl nit
- Amutha, Chinnadurai,Saravanan, Sivaperuman,Muthusubramanian, Shanmugam
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p. 646 - 653
(2013/06/27)
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- Ring opening of pymisyl-protected aziridines with organocuprates
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The pyrimidine-2-sulfonyl (pymisyl) group is introduced as a new protecting group that can be used to activate aziridines towards ring opening. It is readily introduced and removed under mild conditions. Regioselective ring opening of pymisyl-protected 2-methyl-aziridine with organocuprates gives the corresponding sulfonamides in high yields, and the pymisyl group can subsequently be removed upon treatment with a thiolate. The versatility of this new nitrogen protecting group is illustrated with a new synthesis of Selegiline, a monoamine oxidase-B inhibitor marketed for the treatment of Parkinson's disease. Easy on'easy off: The pymisyl group is introduced as a new protecting group for the activation of aziridines towards ring opening with organocuprates (see scheme). It is readily removed under very mild conditions with thiolates. The versatility of the approach is illustrated in a new synthesis of Selegiline, a drug marketed for the treatment of Parkinson's disease.
- Bornholdt, Jan,Felding, Jakob,Clausen, Rasmus P.,Kristensen, Jesper L.
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supporting information; experimental part
p. 12474 - 12480
(2010/12/25)
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- Characterization of route specific impurities found in methamphetamine synthesized by the Leuckart and reductive amination methods
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Impurity profiling of seized methamphetamine can provide very useful information in criminal investigations and, specifically, on drug trafficking routes, sources of supply, and relationships between seizures. Particularly important is the identification of "route specific" impurities or those which indicate the synthetic method used for manufacture in illicit laboratories. Previous researchers have suggested impurities which are characteristic of the Leuckart and reductive amination (Al/Hg) methods of preparation. However, to date and importantly, these two synthetic methods have not been compared in a single study utilizing methamphetamine hydrochloride synthesized in-house and, therefore, of known synthetic origin. Using the same starting material, 1-phenyl-2-propanone (P2P), 40 batches of methamphetamine hydrochloride were synthesized by the Leuckart and reductive amination methods (20 batches per method). Both basic and acidic impurities were extracted separately and analyzed by GC/MS. From this controlled study, two route specific impurities for the Leuckart method and one route specific impurity for the reductive amination method are reported. The intra- and inter-batch variation of these route specific impurities was assessed. Also, the variation of the "target impurities" recently recommended for methamphetamine profiling is discussed in relation to their variation within and between production batches synthesized using the Leuckart and reductive amination routes.
- Kunalan, Vanitha,Daeid, Niamh Nic,Kerr, William J.,Buchanan, Hilary A. S.,McPherson, Allan R.
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experimental part
p. 7342 - 7348
(2010/04/06)
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- POLAR HYDROPHILIC PRODRUGS OF AMPHETAMINE AND OTHER STIMULANTS AND PROCESSES FOR MAKING AND USING THE SAME
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Disclosed are polar, hydrophilic stimulant prodrug compositions comprising at least one stimulant chemically attached to a polar hydrophilic ligand, a salt thereof, a derivative thereof, or a combination thereof. Methods of making and using the same are also disclosed.
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Page/Page column 45
(2008/12/08)
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- Aziridines. 77: cis-trans pair of a N-benzoylaziridine: Dependence of carbonyl reactivity on nitrogen pyramid
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In a multistep process, anthracenide and both 1-benzoyl-2-methyl-3-phenylaziridines 1a form carbanion 4a that abstracts a proton from the solvent THF. The steep N pyramid of cis-1a makes attack of 4a on C=O of cis-1a fast enough to compete with proton abs
- Falkenstein, Reinhard,Stamm, Helmut
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p. 195 - 196
(2007/10/03)
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- EPC-synthesis of functionalised amides via chiral β-nitrogenated organolithium compounds
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The deprotonation of chiral chloroamides or carbamates 1, 4, 7, 10, 13 and 16 with n-butyllithium followed by in situ lithiation with lithium naphthalenide, both at -78°C in THF, leads to the formation of the corresponding chiral dianionic intermediates,
- Foubelo, Francisco,Yus, Miguel
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p. 2911 - 2922
(2007/10/03)
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- Synthesis of enantiomerically pure functionalised amides (EPC-synthesis) from chiral β-aminated organolithium intermediates
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The successive deprotonation-lithiation of chiral chloroamides 1 with n-butyllithium and lithium naphthalenide, respectively, at -78°C leads to the corresponding chiral β-aminated organolithium intermediates 2, which by reaction with different electrophil
- Foubelo, Francisco,Yus, Miguel
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p. 4831 - 4834
(2007/10/02)
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- Single Electron Transfer versus Nucleophilic Ring Opening in Reactions of Cis-Trans Pairs of Activated 2-Phenylaziridines. Strong Influence of Nitrogen Pyramid for N-Benzoylaziridines
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Activated 2-phenylaziridines with a second substituent R in position 3 were made to react with xanthyl anion X(1-).Nucleophilic ring opening is the only reaction that occurs with sulfonyl activation.The analogous N-benzoylaziridines 1 undergo this type of ring opening when the two substituents Ph and R are trans.The cis isomers (cis-1, Ph and R cis) react in this manner to a negligible extent if any.The (nearly) exclusive ring cleavage reaction of cis-1 is C-N homolysis of an intermediate ketyl formed by single electron transfer (SET) from X(1-).This cis-trans phenomenon is in accordance with the hypothesis that the two competing reactions depend in an opposite manner on the steepness of the nitrogen pyramid.A predominant or exclusive final result of SET is reductive aziridine opening and dimerization of the xanthyl radical X(.).Formation of both diastereomers of the amidoethylated xanthene in one case (R = Me) is evidence for a cross combination of X(.) with the radical formed by homolytic ring opening.Cross combination is also a likely path for R = H (no cis-trans isomerism), in addition to reductive ring opening. cis-Aziridines with dimethylcarbamoyl on nitrogen do not react via SET since the ketyl is not stabilized and therefore difficult to generate.Carbonyl attack on both types of acylaziridines competes more or less successfully with the two ring cleavage reactions.
- Falkenstein, Reinhard,Mall, Thomas,Speth, Dieter,Stamm, Helmut
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p. 7377 - 7381
(2007/10/02)
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- HOMOLYTIC AZIRIDINE OPENING (AZA VARIANT OF CYCLOPROPYLCARBINYL-HOMOALLYL REARRANGEMENT) BY ADDITION OF TRIBUTYLTIN RADICAL TO N-ACYLAZIRIDINES. FACTORS CONTRIBUTING TO THE REGIOSELECTIVITY
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AIBN initiated reaction of N-acylaziridines 1 with Bu3SnH in refluxing benzene provided products 5 and 8 of reductive ring opening.Yields (practically quantitative in most cases) fell drastically with steric hindrance of the addition of Bu3Sn to the acyl oxygen of 1.They depended to some extent on the experimental conditions for hydrogen capturing when aziridine homolysis provided a primary radical 3 or 6.The regioselectivity of (probably reversible) ring homolysis can be understood in terms of the stability of the arising radical (3, 6), of stereoelectronic control (e.g. 1i as compared to 1h) and of frontier orbital interactions (1j).A possible difference in bond lengths as explanation for the formation of the primary radical from 1j did not find support from an X-ray structure analysis of N-tosyl-2-methyl-aziridine 11.Isomeric products were obtained only twice (1i, 1j) with a dependence of the ratio 5j:8j on concentration and hydrogen isotope of Bu3SnH.No such dependence was found for the ratio 5:14 (reduction without and with an intervening cyclization of 3 leading to a pyrrolidone) obtained from the N-cinnamoylaziridine 1l.This ratio (1:9 for 1l and 1:3 for 1n) must reflect the E-Z isomers in 3.The observed preference for the formation of E-3 from 2 can be explained by stereoelectronic and steric effects.A cinnamoyl double bond in 5 was saturated depending on experimental conditions.
- Werry, Juergen,Stamm, Helmut,Lin, Pen-Yuan,Falkenstein, Reinhard,Gries, Stefan,Irngartinger, Hermann
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p. 5015 - 5028
(2007/10/02)
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- ALKYLATION OF 2-AZAALLYL ANIONS; A VERSATILE PRIMARY AMINE SYNTHESIS
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Imines from primary amines and mesityl 2-pyridyl ketone react with LDA followed by treatment with an alkyl halide and hydrolysis to give the original amine alkylated at the alpha-position.
- Hornback, Joseph M.,Murugaverl, Balasingam
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p. 5853 - 5856
(2007/10/02)
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