- Preparation method of impurities during synthesis of rivaroxaban
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The invention discloses a preparation method of impurities during the synthesis of rivaroxaban, and belongs to the field of chemical pharmacy. The impurities comprise an impurity A, an impurity B, animpurity C and an impurity D. The invention further comp
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Paragraph 0143-0165
(2019/11/04)
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- Stereoselective Synthesis of Alkylidene Phthalides
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The N,O-diacylhydroxylamine derivative 4 has been prepared and its reactivity with nucleophiles investigated. On reaction with lithium enolates of cyclic or acyclic ketones, 4 is converted stereoselectively to the corresponding alkylidene phthalide. The s
- Dragan, Andrei,Jones, D. Heulyn,Kennedy, Alan R.,Tomkinson, Nicholas C. O.
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supporting information
p. 3086 - 3089
(2016/07/13)
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- PROTECTED LINKER COMPOUNDS
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The invention features protected linker compounds which comprise at one terminus a protected amino group and at another other terminus a phosphorous activating group, such as a phosphoramidite group. These protected linker compounds are introduced chemically at the 5'-end of oligonucleotides for the purpose of preparing 5'-amino modified oligonucleotides. After deprotection, the thereby introduced amino group then allows further modification (e.g. attachment of dyes) or immobilization (on surfaces or beads) of the oligonucleotide. Specifically, the presented amino protecting group is designed to provide such protected linker compounds in a solid form, which facilitates efficient purification by precipitation or crystallization and aliquoting for distribution and storage.
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Page/Page column 31; 33
(2013/07/05)
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- Quantitative solid-state reactions of amines with carbonyl compounds and isothiocyanates
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A series of solid-state reactions is reported of gaseous or solid amines with aldehydes to give imines, with solid anhydrides to give diamides (therefrom imides) or amidic carboxylic salts or imides, with solid imides to give diamides, with solid lactones or carbonates to give functionalized carbamic esters, with polycarbonates to give degradative aminolysis, and with solid isothiocyanates to give thioureas. Diamides give imides by solid-state thermolysis or acid catalysis. Various double, two-step, 3-cascade, and sequential reactions are reported in the solid state without melting. The yields are quantitative in 53 reported reaction examples and no workup (except for washings in four cases) is required in the 100% yield reactions. Three initially solid-state reactions but with liquid product were not quantitative. An upscaling to the kg scale shows promise of the technique for large scale applications. Supermicroscopic analyses with AFM elucidate the solid-state mechanism by virtue of far-reaching anisotropic molecular movements in three-step processes. Gas-solid aminolyses of polycarbonates are also studied with AFM. The implications to sustainable chemistry are discussed. (C) 2000 Elsevier Science Ltd.
- Kaupp, Gerd,Schmeyers, Jens,Boy, Juergen
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p. 6899 - 6911
(2007/10/03)
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- THIOETHER PROTECTION VIA SELECTIVELY CLEAVABLE SULFONIUM SALTS
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There are few protecting groups available for the thioether functionality.The selective cleavage of 4-phthalimidobutyl- and p-methoxybenzylsulfonium salts make these derivatives ideal for thioether protection.
- Doi, Joyce Takahashi,Luehr, Gary W.
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p. 6143 - 6146
(2007/10/02)
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- NMR STUDIES ON IMIDINES. III. (1)H AND (13)C NUCLEAR MAGNETIC RESONANCE STUDY ON THE TAUTOMERISM AND GEOMETRICAL ISOMERISM OF 3-IMINOISOINDOLINONE AND SOME ALKYLATED DERIVATIVES. OBSERVATION OF E AND Z ISOMERS ABOUT A FREE IMINO GROUPING
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3-Iminoisoindolinone (1) and some N-alkyl derivatives (8, 9, 10, 11, 12, 16 and 17) have been fully examined by (1)H and (13)C NMR spectroscopy. 3-(Methylimino)isoindolinone (12) cannot be obtained by reaction of 1 with methylamine, because it rearranges to 3-imino-2-methylisoindolinone (11), which reacts further to 2-methyl-3-(methylimino)isoindolinone (10).Both compounds have been shown to adopt the E configuration predominantly (88 percent for 11 at -55 deg C (CDCl3); 100 percent for 10). 3-(Methylimino)isoindolinone (12) favours the Z configuration (96 percent). Analogous results are found for the butyl derivatives (16, 17). 3-Imino isoindolinone (1) is present as the imino tautomer for 70 percent in DMSO-d6 solution as established by comparison of (13)C NMR chemical shift values of 1 with those of model compounds, 3-imino-2-methyl isoindolinone (11) and 3-(dimethylamino)isoindolinone (8).The tautomeric equilibrium is more extreme towards the imino form for the N-methyl and N-butyl derivatives 12 and 16. 2,3,4,5-tetrahydroisoindolinopyrimidin-6-one served as the imino model compound together with 10. (1)H and(13)C NMR data are given for several phthalic acid derivatives.
- Spiessens, Luc I.,Anteunis, Marc J. O.
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p. 965 - 994
(2007/10/02)
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