Showing papers on "Diazomethane published in 2015"
TL;DR: A novel approach to agrochemically important difluoromethyl-substituted pyrazoles has been developed based on the elusive reagent CF2 HCHN2, which was synthesized for the first time and employed in [3+2] cycloaddition reactions with alkynes.
Abstract: A novel approach to agrochemically important difluoromethyl-substituted pyrazoles has been developed based on the elusive reagent CF2HCHN2, which was synthesized (generated in situ) for the first time and employed in [3+2] cycloaddition reactions with alkynes. The reaction is extremely practical as it is a one-pot process, does not require a catalyst or the isolation of the potentially toxic and explosive gaseous intermediate, and proceeds in a common solvent, namely chloroform, in air. The reaction is also scalable and allows for the preparation of the target pyrazoles on gram scale.
118 citations
TL;DR: In this paper, a short review summarizes recent important developments using peroxides as versatile methylating reagents, including direct methylation and sequential methylation together with other functionalization processes.
Abstract: Methylation is an important transformation in organic chemistry. Methods for methylation in industry and academia still frequently employ hazardous and toxic reagents, such as diazomethane, dimethyl carbonate, methyl iodide, and dimethyl sulfate. From the point of view of sustainable and environmentally friendly chemistry, much effort has been devoted to the discovery and development of alternative methylating reagents. A particularly attractive new methyl source that is attracting attention is derived from the cleavage of peroxides. This short review summarizes recent important developments using peroxides as versatile methylating reagents, including direct methylation and sequential methylation together with other functionalization processes. The corresponding reaction mechanisms are also discussed. 1 Introduction 2 Direct Methylation 2.1 Methylation of C–H Bonds 2.2 Methylation of N–H Bonds 2.3 Methylation of O–H Bonds 3 Methylation together with Other Functionalizations 3.1 Oxidation and Methylation 3.2 Decarboxylative Methylation 3.3 Methylation and Cyclization 4 Conclusions and Perspectives
27 citations
TL;DR: Poly(imidazole-Cu)-mediated C1/C1N2 copolymerization of ethyl diazoacetate involved copper-based carbene radical and α-carbonyl diazomethane radical intermediates, which could be captured by radical traps and detected by room-temperature EPR spectroscopy.
21 citations
TL;DR: In this article, the triazole cycle was used to give all three possible isomers of 1H, 13C, 14N, and 15N NMR spectroscopy.
Abstract: 1H-[1,2,3]Triazolo[4,5-e][1,2,3,4]tetrazine 4,6-dioxide (3) was synthesized by reduction of 1-hydroxy-1H-[1,2,3]triazolo[4,5-e][1,2,3,4]tetrazine 5,7-dioxide (1) with PCl3, reduction of 1-methoxy-1H-[1,2,3]triazolo[4,5-e][1,2,3,4]tetrazine 5,7-dioxide (4) with Na2S2O4, and by the reaction of compound 4 with Et3N. Both methylation of compound 3 with diazomethane and reaction of Ag-salt of compound 3 with MeI occur at the triazole cycle to give all three possible isomers. The structures of the synthesized compounds were confirmed by 1H, 13C, 14N, and 15N NMR spectroscopy.
20 citations
TL;DR: A new cycloaddition for the construction of Δ(2)-pyrazolines containing a α-tert-alkylamino carbon center and subsequent facile protonolytic N-N bond cleavage allows the synthesis of a key intermediate of the amathaspiramides and other α,α-disubstituted amino acid derivatives.
Abstract: Concise routes for the total and formal syntheses of the amathaspiramides were developed through a formal [3+2] cycloaddition between lithium(trimethylsilyl)diazomethane and α,β-unsaturated esters. The effectiveness of this new cycloaddition for the construction of Δ2-pyrazolines containing a α-tert-alkylamino carbon center and subsequent facile protonolytic NN bond cleavage allows the synthesis of a key intermediate of the amathaspiramides and other α,α-disubstituted amino acid derivatives.
18 citations
TL;DR: In this paper, an efficient, high-yielding preparative synthesis of 3(5),3′(5′)-dimethyl-4,4′-bipyrazole, a new multi-purpose tecton for the supramolecular synthesis of metal-organic polymers and hydrogen-bonded frameworks, is described.
9 citations
TL;DR: In this article, the use of aluminum carbenoids over traditional cyclopropanation reagents (diazomethane, Simmons-Smith and Furukawa reagents) for the preparation of cycloprocyclopropyl amines was demonstrated.
9 citations
TL;DR: The absence of racemization during the methylation reaction and the removal of Fms group were demonstrated by synthesising a pair of diastereomeric dipeptides and the Fmsgroup can be interchangeable with the Fmoc group in the synthesis of N‐methylated peptides using standard FmOC‐based strategies.
Abstract: This work reports an efficient Lewis acid catalysed N-methylation procedure of lipophilic α-amino acid methyl esters in solution phase. The developed methodology involves the use of the reagent system AlCl3/diazomethane as methylating agent and α-amino acid methyl esters protected on the amino function with the (9H-fluoren-9-yl)methanesulfonyl (Fms) group. The removal of Fms protecting group is achieved under the same conditions to those used for Fmoc removal. Thus the Fms group can be interchangeable with the Fmoc group in the synthesis of N-methylated peptides using standard Fmoc-based strategies. Finally, the absence of racemization during the methylation reaction and the removal of Fms group were demonstrated by synthesising a pair of diastereomeric dipeptides.
7 citations
Patent•
18 Nov 2015
TL;DR: In this article, a stable isotope labeling method was proposed for the detection and quantification of a phospholipid using trimethylsilyl diazomethane.
Abstract: The present invention discloses a phospholipid classification detection and quantification method based on stable isotope labeling, and belongs to the technical field of phospholipid quantification detection methods. According to the method, mainly trimethylsilyl diazomethane is used to respectively generate diazomethane and deuterium-labeled diazomethane in a methyl tert-butyl ether/methanol/1N hydrochloric acid solution system and a methyl tert-butyl ether/deuteromethanol/1N deuterium chloride solution system in an in-situ manner so as to further respectively carry out methyl esterification on the phosphoric acid group or carboxylic acid group in the phospholipid molecule to generate the light isotope labeled-phospholipid methyl esterification derivative and the heavy isotope labeled-phospholipid methyl esterification derivative, wherein the light isotope labeled-phospholipid methyl esterification derivative and the heavy isotope labeled-phospholipid methyl esterification derivative have the same physical and chemical properties and different molecular weights; and the relative intensity of the light isotope labeled-mass spectrum peak signal and the heavy isotope labeled-mass spectrum peak signal are compared to associate with the phospholipid molecule amount in the sample so as to achieve the relative quantification on the phospholipid. The method of the present invention has characteristics of enhanced sensitivity and completion within a shor time.
6 citations
TL;DR: A series of newly substituted thieno[3,2g]chromene derivatives were synthesized from 1-(7-mercapto-2,2-dimethylchroman-6-yl)ethanone (3) as starting material as mentioned in this paper.
Abstract: A series of newly substituted thieno[3,2-g]chromene derivatives were synthesized from 1-(7-mercapto-2,2-dimethylchroman-6-yl)ethanone (3) as starting material. The compound 3 in turn was synthesized by reacting of 1-(2,4-dihydroxyphenyl)ethanone with isoprene to get compound 2 followed by its reaction with phosphorus pentasulfide. Condensation of 3 with N-phenylchloroacetamide or phenacylbromide gave the corresponding thienochromene derivatives 5 and 6. Also, compound 3 was reacted with maleic anhydride and acrylonitrile to afford the corresponding derivatives 8 and 9, respectively. Alkylation of 3 with diazomethane or ethyl bromoacetate afforded the corresponding S-substituted derivatives 10 and 11. The latter compound 11 was cyclized to ester derivative 12, which was obtained directly from 3 on reaction with ethyl bromoacetate. Treatment of 12 with hydrazine hydrate afforded the corresponding hydrazide 13, which was condensed with aromatic aldehydes or acetyl acetone to yield the corresponding Schiff’s bases 14a–d
S-pyrazolo derivative 15, respectively. Finally, compound 13 was treated with 2,5-hexandione or carbon disulfide to give the corresponding compounds 16 and 17, respectively. Some of the newly synthesized compounds exhibited better anti-inflammatory activities than the reference controls with low concentrations. The structures of newly synthesized compounds were confirmed by chemical, elemental, and spectroscopic evidences. The detailed synthesis, spectroscopic data, and pharmacological activities were reported.
4 citations
TL;DR: In this paper, an expedient method for the direct conversion of acyl isothiocyanates to 2,4-disubstitued thiooxazoles and 2, 4-dissubstituted oxazole sulfonyl chlorides is described.
Abstract: An expedient method for the direct conversion of acyl isothiocyanates to 2,4-disubstitued thiooxazoles and 2,4-disubstituted oxazole sulfonyl chlorides is described. The method takes advantage of an early observation by Sheehan and the reaction of diazomethane with isocyanates to form oxazolones. However, in this case an acyl isothiocyanate is utilized as well as the readily available TMS-diazomethane to provide access to the desired 4-substituted sulfur derivatives. The 2,4-disubstituted oxazole systems synthesized represent novel thiooxazoles and oxazole sulfonyl chlorides not previously described.
TL;DR: In the Simmons-Smith reaction vinblastine and vincristine cyclopropanated in the carbon carbon double bond in position 14 and 15 of the vindoline monomer were obtained as discussed by the authors.
Abstract: New derivatives of natural compounds, galanthamine using in treatment of Alzheimer’s disease and antitumor dimer alkaloids vinblastine and vincristine were synthesized. In the course of the reaction between galanthamine and diazomethane in the presence of a catalyst, such as palladium(II) acetate or copper(I) bromide, methylene insertion into the aromatic ring was observed instead of the expected cyclopropanation of the carbon-carbon double bond. New vindoline derivatives conjugated with amino acid esters were prepared. In Simmons-Smith reaction vinblastine and vincristine cyclopropanated in the carbon carbon double bond in position 14 and 15 of the vindoline monomer were obtained. New dimer alkaloids showed significant inhibiting effects in several tumor cell lines.
TL;DR: In this paper, a collection of methods which allow for the detection of non-esterified fatty acid (NEFA) and hydroxy NEFA without the use of diazomethane is presented.
Abstract: In many branches of lipid science, researchers are interested in non-esterified fatty acid (NEFA) content and composition. For many years, diazomethane was the reagent of choice to selectively derivatize and then detect NEFA due to its highly specific methylation of the carboxylic acid functional group. While the activity of this derivatizing reagent is very defined, it is dangerous and can be difficult to obtain. In this brief review, we have compiled a collection of methods which allow for the detection of NEFA and hydroxy NEFA without the use of diazomethane. We have concentrated on methods that employ three distinct approaches of selective quantification/extraction, purification from total lipids and derivatization techniques.
Chemical reactions that occur during selective extraction of NEFA using a quaternary ammonium salt (a) and the later pyrolytic derivatization when the mixture is placed in the hot injection port of a GC (b).
TL;DR: In this article, 4,4'-Dimonochloroacetyl diphenylselenide (2) was prepared as a new precursor for the title studies by chloroaceylation.
Abstract: 4,4'-Dimonochloroacetyl diphenylselenide (2) was prepared as a new precursor for the title studies by chloroaceylation of diphenylselenide (1). 2 Interacts with thiourea to afford 4,4'-di(2”-aminothiazol-4”-yl) diphenyl selenide (3). Condensation of 3 with aromatic aldehydes in the presence of a catalytic amount of dry piperidine furnished aldimines (4).Interaction of 4 with mercaptoacetic acid afforded 4,4'-di(2”-(2'”-substituted phenyl-3'”-thiazolo-4'”-thiazolidinon)-3'”-yl) diphenylselenides (6). Schiff bases 4 interact with mono chloroacetyl chloride in dry dioxane and triethylamine produced 4,4'-di(2”-(4'”-substituted phenyl-3'”-chloro-2'”-azetidinon-1'”-thiazolo)-1'”-yl) diphenylselenides (8). 1,3-Dipolar cyclonucleophilic addition of diazomethane to certain of 4 gave 4,4'-di(2”-(5'”-substituted phenyl-Δ2-1'”,2'”,3'”,-triazoline thiazolo)-1'”-yl) diphenylselenides (10). 2 Interacts with secondary heteroalicylic amines to afford 4,4'-diglycyl diphenylselenides (11). The structures of the synthesized ...
Patent•
08 Apr 2015
TL;DR: In this article, a method for preparing a DGAT-1 inhibitor intermediate is presented, which comprises the following steps: reacting trans-4-(4-halogeno phenyl)cyclohexanecarboxylic acid chloride with diazomethane, and generating trans- 4-(4-, halogenophenyl) cyclohexyl diazo-ketone; and performing Wolff rearrangement on trans-four-(4,halogenoencarboxyl)chenyldiazo -ketone, and trans 4-
Abstract: The invention discloses a method for preparing a DGAT-1 inhibitor intermediate. The method comprises the following steps: reacting trans-4-(4-halogeno phenyl)cyclohexanecarboxylic acid chloride with diazomethane, and generating trans-4-(4-halogeno phenyl)cyclohexyl diazo-ketone; and performing Wolff rearrangement on trans-4-(4-halogeno phenyl)cyclohexyl diazo-ketone, and generating trans-4-(4-halogeno phenyl)cyclohexyl acetic acid. According to the method disclosed by the invention, the reaction steps are reduced, and the raw material cost is reduced.
Patent•
09 Dec 2015
TL;DR: In this article, the carboxyl group is protected by diphenyl diazomethane, which reduces the generation of impurities and improves the quality of axetil.
Abstract: The invention relates to a preparation method of cefuroxime axetil. The preparation method comprises the following steps: (1) reacting de-ammoniated formyl cephalosporanic acid with diphenyl diazomethane to generate acetyl-diphenyl methyl cephalosporanate; (2) reacting diphenyl methyl de-ammoniated formyl cephalosporanate with trichloroacetic isocyanate to generate diphenyl methyl cefuroxime ester; (3) hydrolyzing diphenyl methyl cefuroxime ester to obtain cefuroxime acid; (4) reacting cefuroxime acid with 1-acetoxyl-bromoethane to generate cefuroxime axetil. During the preparation process, the carboxyl group is protected by diphenyl diazomethane, the generation of impurities is reduced, and the product quality is improved.
TL;DR: In this paper, a formal [3+2] cycloaddition between lithium(trimethylsilyl)diazomethane and α,β-unsaturated esters was developed for the synthesis of α,α-disubstituted amino acid derivatives.
Abstract: Concise routes for the total and formal syntheses of the amathaspiramides were developed through a formal [3+2] cycloaddition between lithium(trimethylsilyl)diazomethane and α,β-unsaturated esters. The effectiveness of this new cycloaddition for the construction of Δ2-pyrazolines containing a α-tert-alkylamino carbon center and subsequent facile protonolytic NN bond cleavage allows the synthesis of a key intermediate of the amathaspiramides and other α,α-disubstituted amino acid derivatives.
Patent•
27 Jul 2015
TL;DR: In this article, a stable isotope labeling method was proposed for the detection and quantification of a phospholipid using trimethylsilyl diazomethane.
Abstract: The present invention discloses a phospholipid classification detection and quantification method based on stable isotope labeling, and belongs to the technical field of phospholipid quantification detection methods. According to the method, mainly trimethylsilyl diazomethane is used to respectively generate diazomethane and deuterium-labeled diazomethane in a methyl tert-butyl ether/methanol/1N hydrochloric acid solution system and a methyl tert-butyl ether/deuteromethanol/1N deuterium chloride solution system in an in-situ manner so as to further respectively carry out methyl esterification on the phosphoric acid group or carboxylic acid group in the phospholipid molecule to generate the light isotope labeled-phospholipid methyl esterification derivative and the heavy isotope labeled-phospholipid methyl esterification derivative, wherein the light isotope labeled-phospholipid methyl esterification derivative and the heavy isotope labeled-phospholipid methyl esterification derivative have the same physical and chemical properties and different molecular weights; and the relative intensity of the light isotope labeled-mass spectrum peak signal and the heavy isotope labeled-mass spectrum peak signal are compared to associate with the phospholipid molecule amount in the sample so as to achieve the relative quantification on the phospholipid. The method of the present invention has characteristics of enhanced sensitivity and completion within a shor time.
Dissertation•
26 Nov 2015
TL;DR: In this article, the authors present a Lay Summary and acknowledgments of the authors' work, including acknowledgements and acknowledgements of authors' acknowledgements, and a discussion of their work.
Abstract: ....................................................................................................... ii Lay Summary .................................................................................................. iii Acknowledgments ............................................................................................ iv Abbreviations ................................................................................................... v
Patent•
04 Mar 2015
TL;DR: In this paper, a method for preparing 4-amino-N-[(2R, 3S)-3 amino-2-hydroxy-4-benzene butyl]-N-isobutyl benzsulfamide is presented.
Abstract: The invention discloses a method for preparing 4-amino-N-[(2R,3S)-3-amino-2-hydroxy-4-benzene butyl]-N-isobutyl benzsulfamide. The method comprises the following steps: S1: enabling L-phenylalanine and diazomethane to react to obtain a diazo methyl ketone intermediate product, and enabling the diazo methyl ketone intermediate product and haloid acid to react to obtain a compound A; S2, conducting carbonyl deoxidation on the compound A to obtain a compound B; S3, under the existence of iso-butylamine, conducting cyclization reaction and ring-opening reaction on the compound B in sequence to obtain a compound C; S4, enabling the compound C and nitrobenzenesulfonyl chloride to react to obtain a compound D; S5, conducting nitro reduction on the compound D to obtain the 4-amino-N-[(2R,3S)-3-amino-2-hydroxy-4-benzene butyl]-N-isobutyl benzsulfamide. The method is simple in course, low in cost, mild in condition, and higher in intermediate product stability, and is beneficial for industrial application.
TL;DR: In this article, an expedient method for the direct conversion of acyl isothiocyanates to 2,4-disubstitued thiooxazoles and 2, 4-dissubstituted oxazole sulfonyl chlorides is described.
Abstract: An expedient method for the direct conversion of acyl isothiocyanates to 2,4-disubstitued thiooxazoles and 2,4-disubstituted oxazole sulfonyl chlorides is described. The method takes advantage of an early observation by Sheehan and the reaction of diazomethane with isocyanates to form oxazolones. However, in this case an acyl isothiocyanate is utilized as well as the readily available TMS-diazomethane to provide access to the desired 4-substituted sulfur derivatives. The 2,4-disubstituted oxazole systems synthesized represent novel thiooxazoles and oxazole sulfonyl chlorides not previously described.
Patent•
16 Dec 2015
TL;DR: In this paper, a preparation method for (2R, 3S)-1-chlorine-3-tert-butoxycarbonylamino-4-phenyl-2-butanol is presented.
Abstract: The invention provides a preparation method for (2R,3S)-1-chlorine-3-tert-butoxycarbonylamino-4-phenyl-2-butanol. The preparation method comprises the steps that L-phenylalanine is taken as raw materials, protected by adopting benzyl, esterified and then catalyzed through NMM to generate a mixed anhydride compound, the mixed anhydride compound reacts with diazomethane to generate diazoketone, a reduction reaction and palladium carbon reduction are performed, and finally the intermediate (2R,3S)-1-chlorine-3-tert-butoxycarbonylamino-4-phenyl-2-butanol is obtained. According to the preparation method, the low-cost benzyl is adopted to protect amidogen, the synthetic route is reasonable, the operation technology is simple, safe and high in yield, industrialization can be well achieved, and the production efficiency is improved.
01 Jan 2015
TL;DR: In this article, the authors demonstrate the advantage of using aluminum carbenoids over traditional cyclopropanation reagents (diazomethane, SimmonseSmith and Furukawa reagents) for the preparation of cycloprocyclopropyl amines.
Abstract: The reaction of enamines with 2 equiv of Et3Al and CH2I2 at room temperature in CH2Cl2 results in the formation of cyclopropyl amines in high yields (68e89%). Substituted 1-phenylcyclopropan-1-ols were also synthesized from trimethylsilyl enol ethers. The paper demonstrates the advantage of using aluminum carbenoids over traditional cyclopropanation reagents (diazomethane, SimmonseSmith and Furukawa reagents) for the preparation of cyclopropyl amines. 2015 Published by Elsevier Ltd.
Journal Article•
TL;DR: The reaction of thionyl chloride with 7-chloro-1-cyclopropyl-6-fluoro-1,4-dihydroquinoline-3-carboxylic acid gave acid chloride.
Abstract: Reaction of thionyl chloride with 7-chloro-1-cyclopropyl-6-fluoro-1,4-dihydro-4-
oxoquinoline-3-carboxylic acid 1 gave acid chloride 2. Compound 2 was reacted with
glycine and D-glutamic acid to afford 2-(7-chloro-1-cyclopropyl-6-fluoro-4-oxo-1,4-
dihydroquinoline-3-carbonyl) aminopantandioicacid 3a and 2-(7-chloro-1-cyclopropyl-6-
fluoro -4- oxo-1,4-dihydroquinoline-3-carbonyl)aminoaceticacid 3b. These compounds were
changed to chloromethyl ketone derivatives 5a-b from diazomethane and then HCl (g)in dry
diethyl ether.
Patent•
16 Sep 2015
TL;DR: In this article, a wood preservative consisting of 20-30% of copper carbonate, 30-40% of a compound I, 5-10% of allethrin and 30% of ammonia water was revealed.
Abstract: The invention discloses a wood preservative. The wood preservative comprises, by mass, 20-30% of copper carbonate, 30-40% of a compound I, 5-10% of allethrin and 30-40% of ammonia water. The structure of the compound I is represented by a formula shown in the specification; and a preparation method of the compound I comprises the following steps: mixing a 2,4-dihydroxyacetophenone and diazomethane ether mixed liquor with a boron trifluoride-ether complex, stirring for about 0.2-1h, carrying out a refluxing reaction for 5-7h, filtering after the reaction, washing the above obtained solid, drying, re-crystallizing to obtain an intermediate I, and reacting the intermediate I with 5-methyl-furan-2-formaldehyde to obtain an intermediate II; and reacting the intermediate II with 4-sulfamoylphenyl hydrazine to obtain an intermediate III, and reacting the intermediate III with dichloromethane and boron tribromide to obtain the target compound.
Patent•
09 Nov 2015
TL;DR: In this article, a method and equipment for preparing diazomethane is described, which is used in the field of organic synthesis, with the aim to overcome shortcomings of existing methods.
Abstract: The invention relates to a method and equipment for preparing diazomethane, and belongs to the field of organic synthesis. The method and the equipment have the advantages that the method and the equipment aim to overcome shortcomings of existing methods for preparing diazomethane and are short in process route, low in raw material cost and high in yield, preparation procedures are safe and environmental friendly, and effects of industrial continuous production can be realized; the method for preparing the diazomethane is implemented by the aid of the equipment, the diazomethane can be generated from a N-methyl-N-nitroso material and alkali metal hydroxide by means of completely closed reaction, stable organic solution can be formed by means of timely extraction by the aid of extraction agents, accordingly, the retention time of the diazomethane in water can be shortened, the decomposition rate of the diazomethane which can generate methyl alcohol and nitrogen when in water can be reduced, the diazomethane yield can be increased, and safety risks of operator poisoning and explosion due to leakage of gaseous diazomethane can be prevented.
TL;DR: Difluoromethyl diazomethane was generated in situ and utilized in [3 + 2] cycloadditions for the first time in this paper, where it was used in [
Abstract: Difluoromethyl diazomethane is generated in situ and utilized in [3 + 2] cycloadditions for the first time.
Patent•
02 Sep 2015
TL;DR: In this paper, a wood preservative is described from the following ingredients by weight percent: 20-30% of copper carbonate, 30-40% of a compound I, 5-10% of allethrin and 30% of ammonia water, wherein the compound I is shown as the specification.
Abstract: The invention discloses a wood preservative. The wood preservative is prepared from the following ingredients by weight percent: 20-30% of copper carbonate, 30-40% of a compound I, 5-10% of allethrin and 30-40% of ammonia water, wherein the compound I is shown as the specification. A preparation method of the compound I comprises the steps of mixing 2,4-Dihydroxyacetophenone, mixed solution of diazomethane and diethyl ether and boron trifluoride-etherate under the stirring action of an ice-water bath, stirring for 0.2-1h, performing refluxing reaction for 5-7h, filtering after reacting, washing obtained solids, drying, recrystallizing to obtain an intermediate I, enabling the intermediate I to be reacted with 5-methyl-furan-2-formaldehyde to obtain an intermediate II, enabling the intermediate II to be reacted with aminosulfonylphenylhydrazine to obtain an intermediate III, and enabling the intermediate III to be reacted with dichloromethane and boron tribromide to obtain the target compound.
Patent•
07 Jan 2015
TL;DR: In this paper, a chiral optically pure (S)-3-aminovaleric acid (VI) was synthesized by using a natural compound amino acid L-(-)-2-aminobutyric acid (I) as the initial raw material.
Abstract: The invention discloses a synthesis method of chiral optically-pure (S)-3-aminovaleric acid (VI), which comprises the following steps: by using a natural compound amino acid L-(-)-2-aminobutyric acid (I) as the initial raw material, carrying out protection on amino group in the compound (I) molecule in an organic solvent by using di-tert-butyl dicarbonate to obtain N-tert-butyloxycarbonyl-2-aminobutyric acid (II); carrying out acyl-chlorination reaction on the compound (II) to obtain N-tert-butyloxycarbonyl-2-aminobutyryl chloride (III); dissolving the compound (III) in an organic solvent, and reacting with trimethyl silicon diazomethane to obtain a diazo-ketone compound (IV) with one more carbon atom; carrying out Wolff rearrangement reaction on the compound (IV) in the presence of silver benzoate to obtain a compound (V); and hydrolyzing methyl ester of the compound (V) under alkaline conditions to obtain the compound tert-butyloxycarbonyl protected (S)-3-aminovaleric acid (VI).
TL;DR: In this paper, α-silylated alkynylhydrazones are prepared by the reaction of substituted aluminium compounds with trimethylsilyl diazomethane (II).
Abstract: Various α-silylated alkynylhydrazones are prepared by the reaction of substituted alkynylaluminium compounds with trimethylsilyl diazomethane (II).