1117-97-1Relevant articles and documents
Quantum Chemical Studies of Model Cytochrome P450 Oxidation of Amines. MNDO Pathways for Alkylamine Reactions with Singlet and Triplet Oxygen
Goldblum, Amiram,Loew, Gilda H.
, p. 4265 - 4272 (1985)
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.
Stereostructure Clarifying Total Synthesis of the (Polyenoyl)tetramic Acid Militarinone B. A Highly Acid-Labile N-Protecting Group for Amides ?
Drescher, Christian,Brückner, Reinhard
supporting information, p. 6194 - 6199 (2021/08/18)
The 5S, 8′R, and 10′R configurations of militarinone B (3), which is a natural product from Paecilomyces militaris, should equal those in its biosynthetic precursor, militarinone C. The configuration at C-1′ emerged from syntheses of the militarinone B candidates 1′′S- and 1′′R-(5S,8′R,10′R)-3 from the building blocks 9, 11, 14, and 15a while introducing TMB as a more acid-labile N-protecting group for β-ketoamides than DMB. Comparisons of 1′′S- and 1′′R-(5S,8′R,10′R)-3 with natural militarinone B (3; reisolated from Nature) revealed identity versus distinctness.
One-pot method for preparing O-alkyl hydroxylamine hydrochloride and N,O-dialkyl hydroxylamine hydrochloride
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Paragraph 0032-0033, (2020/10/20)
The invention relates to the field of organic synthesis, in particular to a one-pot method for preparing O-alkyl hydroxylamine hydrochloride and N,O-dialkyl hydroxylamine hydrochloride. The method comprises the following steps: S1, acetylation: mixing hydroxylamine hydrochloride with water and methyl acetate, and dropwise adding a sodium hydroxide solution while stirring at room temperature to obtain an intermediate acetyl hydroxylamine; S2, alkylation: dropwise adding an alkylation reagent into the reaction kettle at normal temperature, and then heating the reactants for reaction; S3, hydrolysis and purification: after the reaction is qualified, adding concentrated sulfuric acid, performing heating hydrolysis, after the reaction is qualified, adding caustic soda flakes or liquid caustic soda to adjust the pH value to 12, carrying out atmospheric distillation and hydrochloric acid acidification, cooling the product for crystallization, and centrifuging and drying the crystal to obtaina final product. According to the invention, methyl acetate is used as an acetyl protective agent, and compared with ethyl acetate, methyl acetate has the advantages of good water solubility, small reaction steric hindrance, sufficient protection, few impurities, low price and cost and the like; therefore, the method has the advantages of high product purity, simple process operation, accessible raw materials, simple wastewater components and environment friendliness, and is suitable for industrial production.
Method for coproducing vasoxine hydrochloride and N,O-dimethylhydroxylamine hydrochloride
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Paragraph 0042-0048, (2017/04/03)
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.
