- Method for coproducing vasoxine hydrochloride and N,O-dimethylhydroxylamine hydrochloride
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The invention relates to the technical field of compound synthesis methods, particularly a method for coproducing vasoxine hydrochloride and N,O-dimethylhydroxylamine hydrochloride. The method comprises the following steps: carrying out methylation reaction on hydroxylamine salt under alkaline conditions by using a methylating agent to obtain a reaction solution containing vasoxine and N,O-dimethylhydroxylamine, rectifying to separate a vasoxine bottom solution and an N,O-dimethylhydroxylamine crude distillate, respectively adding hydrochloric acid for salification, concentrating and crystallizing under reduced pressure, cooling, carrying out vacuum filtration, recrystallizing with water or methanol, and drying to obtain the vasoxine hydrochloride product and N,O-dimethylhydroxylamine hydrochloride product. The method has the advantages of simple and reliable technique, high product quality, high total yield and low comprehensive cost, and is more friendly to the environment and suitable for industrial production.
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Paragraph 0042-0048
(2017/04/03)
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- MANNICH BASE N-OXIDE DRUGS
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The invention relates to Mannich base N-oxides of drugs containing acidic N- H groups. Pharmaceutical compositions comprising therapeutically effective amount of Mannich base N-oxides, or a pharmaceutically acceptable salt or prodrug thereof, are disclosed. Further, the invention relates to methods of using the compounds, alone or in combination with one or more other active agents or treatments, are disclosed.
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Page/Page column 65-66
(2008/12/07)
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- METHODS FOR CONVERSION OF TYROSINE TO P-HYDROXYSTYRENE AND P-HYDROXYCINNAMIC ACID
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Three different reaction steps were combined to provide methods for preparing p-hydroxystyrene and p-hydroxycinnamic acid monomers from tyrosine. The three steps include reductive alkylation of tyrosine, followed by oxidation to the N-oxide, and thermal Cope elimination. During Cope elimination, either p-hydroxycinnamic acid or p-hydroxystyrene was produced depending on the absence or presence of base, respectively. Additionally, p-acetoxystyrene may be prepared by reacting the prepared p-hydroxystyrene either directly or after isolation with an acetylating agent.
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Page/Page column 7
(2008/12/06)
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- Tamoxifen stimulates calcium entry into human platelets
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The anti-estrogenic drug tamoxifen, which is used therapeutically for treatment and prevention of breast cancer, can lead to the development of thrombosis. We found that tamoxifen rapidly increased intracellular free calcium [Ca]i in human platelets from
- Dobrydneva, Yuliya,Weatherman, Ross V.,Trebley, Joseph P.,Morrell, Melinda M.,Fitzgerald, Megan C.,Fichandler, Craig E.,Chatterjie, Nithiananda,Blackmore, Peter F.
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p. 380 - 390
(2008/03/12)
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- A Short and Efficient Synthesis of (S)-4-Methylene Proline Benzyl Ester from (S)-Pyroglutamic Acid
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(S)-4-methylene proline benzyl ester 2 was synthesized from benzyl N-tert-butoxycarbonyl pyroglutamate through a Mannich and a Cope elimination reactions.
- Panday, Sharad Kumar,Griffart-Brunet, Dominique,Langlois, Nicole
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p. 6673 - 6676
(2007/10/02)
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- Pyrimidine derivatives
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A pyrimidine derivative represented by the formula STR1 wherein the variables are defined below in the specification, and their production and herbicidal activities are described.
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- Secondary α hydrogen-deuterium kinetic isotope effects in the syn-elimination reaction of 2-phenylethyldimethylamine oxide
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The secondary α-deuterium kinetic isotope effect has been measured for the thermal reaction of 2-phenylethyldimethylamine oxide in 90 mol percent DMSO-H2O at 60.0 deg C.A large secondary α-deuterium isotope effect of 1.158 per α-D was found, which indicates significant C-N bond rupture and very little double bond formation at the transition state for this concerted syn-elimination process.The observed large normal value for (kH/kD)α is discussed in terms of the use of secondary α-D isotope effects for the determination of stereochemistry for a concerted elimination process.Various isotope effects found for the syn elimination of the above amine oxide and those for the anti elimination of 2-arylethyltrimethylammonium salts with ethoxide are considered with respect to the relative transition state structures for syn- and anti-elimination reactions.
- Smith, Peter James,Westaway, Kenneth Charles
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p. 2149 - 2153
(2007/10/02)
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- Process of preparing hydroxyarylaldehydes
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An improvement in the process for preparing hydroxyarylaldehydes is disclosed where a phenolic compound is reacted with formaldehyde, in the presence of a catalyst such as a titanium or zirconium containing catalyst, optionally in the presence of a catalyst promoter, wherein the improvement is the addition of a yield effective amount of a modifier having the formula: STR1 where R1 is selected from the group consisting of: an alkyl group having from 1 to 12 carbon atoms, a cycloalkyl group that can have 5 and 6 carbon atoms, and an H, and where R2 is selected from the group consisting of: an alkyl group having from 1 to 12 carbon atoms, and a cyclo alkyl group that can have 5 to 6 carbon atoms; and where R1 and R2 can together form a cyclic group that can have 5 and 6 carbon atoms.
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- EVOLUTION THERMIQUE DE N-OXYDES DE DIMETHYLAMINO-5 ALCANOLS-1 SUBSTITUES EN 5. COMPETITION ENTRE REARRANGEMENTS DE COPE ET DE MEISENHEIMER
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The effect of the substituent R in the 5 position was studied in the decomposition of 1,5-aminoalcohol N-oxides: Meisenheimer rearrangements takes place when R is the vinyl group but is not observed with the phenyl substituent; elimination to alkenol only
- Barbry, Didier,Hasiak, Bruno,Augait, Jean-Michel,Couturier, Daniel
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p. 956 - 961
(2007/10/02)
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- Quantum Chemical Studies of Model Cytochrome P450 Oxidation of Amines. MNDO Pathways for Alkylamine Reactions with Singlet and Triplet Oxygen
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Reaction pathways for oxidation of ammonia and mono-,di-,and trimethylamine by singlet and triplet oxygen atoms as models for cytochrome P450 enzymatic oxidation have been characterized by using the semiempirical molecular orbital method MNDO.Enthalpies of formation have been calculated for reactants, transition states, intermediates, and produts on closed shell and triplet pathways,and free energies of reaction and activation have been calculated from them.Energy minima and transition states have been verified by calculation of force constans.The results indicate a two-step,addition-rearrangement mechanism for nonradical oxidation leading to both N-hydroxy and N-methoxy products via N-oxide intermediates.While barriers to the rearrangement are higher than to N-oxide formation,the first step is determining the overall reaction in the gas phase.On a triplet surface, both α-C- and N-oxidation are competitive.N-Oxidation via an addition mechanism appears to be favored over on H-abstractionmechanism.However, in contrast to a closed-shell mechanism, no stable N-oxide radical intermediate is found, and the barrier to formation of N-hydroxy and N-methoxyl products on a triplet surface is grater.Additional gas phase, solution, and enzymatic studies, particulary focusing on identification of transient intermediates and products, are necessary to further distinguisch among these mechanisms.
- Goldblum, Amiram,Loew, Gilda H.
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p. 4265 - 4272
(2007/10/02)
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