Preparation of the 2,3-anhydro-4,6-O-benzylidene derivatives of methyl α- and β-D-talopyranoside and of methyl α-D-gulopyranoside

1980 ◽  
Vol 33 (5) ◽  
pp. 1021 ◽  
Author(s):  
JL Frahn
Keyword(s):  
Dimethyl Sulfoxide ◽  
Sodium Methoxide ◽  
Room Temperature ◽  
Derivatives Of

Instructions are given for preparing the title compounds in reproducibly good yields from the appropriate anomer of methyl 4,6-O-benzylidene-2,3-di-O-tosyl-D-galactopyranoside. The α-anomer is converted into a mixture of the anhydro-α-taloside and anhydro-α- guloside by reaction with sodium methoxide in dimethyl sulfoxide as solvent at room temperature. The β-anomer forms the anhydro-β-taloside under similar conditions but with dioxan as solvent for the reactants.

Synthesis and antibacterial activity of some 1-(2-propynyl) and 1-propadienyl derivatives of 1,4-dihydro-4-oxoquinoline-3-carboxylic acids and similar heterocycles

1991 ◽  
Vol 56 (2) ◽  
pp. 439-448 ◽  
Author(s):  
Stanislav Rádl ◽  
Lenka Kovářová ◽  
Jiří Holoubek
Keyword(s):  
Antibacterial Activity ◽  
Dimethyl Sulfoxide ◽  
Carboxylic Acids ◽  
Potassium Carbonate ◽  
Potassium Hydroxide ◽  
Room Temperature ◽  
Ethyl Esters ◽  
The Other ◽  
Other Hand ◽  
Derivatives Of

N-Alkylation of IIIa, IIIb, IIId - IIIf and 9-acridanone with 3-bromopropyne in dimethyl sulfoxide in the presence of potassium carbonate yielded N-(2-propynyl) derivatives IVa - IVe and VIa, respectively. Ethyl esters IVa, IVb, and IVe were hydrolyzed to IVf - IVh, respectively. Compounds IVf, IVg, IVctreated with bases yielded N-propadienyl derivatives Va - Vc. On the other hand 2-substituted compounds IVd and IVh did not change under the same conditions. Compound VIa treated with powdered potassium hydroxide in dimethyl sulfoxide at room temperature yielded N-(1-propynyl) derivative VII.

Asymmetric induction in the Sommelet rearrangement of chiral benzyl sulfonium salts

1976 ◽  
Vol 54 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Stewart John Campbell ◽  
David Darwish
Keyword(s):  
Sodium Methoxide ◽  
Room Temperature ◽  
Exchange Resin ◽  
Shift Reagent ◽  
Asymmetric Induction ◽  
High Yield ◽  
Sulfonium Salts ◽  
Sodium Methoxide Solution ◽  
Derivatives Of ◽  
Sulfone Derivatives

The Sommelet rearrangement of (+)-ethylmethyl-p-nitrobenzylsulfonium perchlorate, (+)-1, and (+)-ethylmethyl-p-chlorobenzylsulfonium perchlorate, (+)-2, are described. Elution of (+)-1 through an hydroxide exchange resin generated ethylmethylsulfonium p-nitro-benzylide (+)-3 which decomposed in methanol at room temperature to ethyl 2-methyl-5-nitro-benzyl sulfide, 6, and (+)-methyl α-(2-methyl-5-nitrophenyl)ethyl sulfide, (+)-7, with 18 to 20.3% asymmetric induction. Decomposition of (+)-2 in sodium methoxide solution at 70 °C for 2 h produced ethyl 2-methyl-5-chlorobenzyl sulfide, 8, and (+)-methyl α-(2-methyl-5-nitro-phenyl)ethyl sulfide, (+)-9, with 21 to 25.5% asymmetric induction. The lower estimates of asymmetric induction for each sulfide were made by comparison with specific rotations of authentic samples obtained by synthesis and resolution. The higher estimates were obtained by the use of a chiral lanthanide shift reagent Eu(hfbc)3 with the sulfone derivatives of these chiral sulfides. The ylide (+)-3 reacted with aldehydes in high yield to produce oxiranes with no induction of asymmetry.

Synthesis of 3-methyl-4H-benzo[b][1,4]thiazine-2-carboxylates using CAN as a catalyst and its conversion into guanidines.

2020 ◽  
Vol 07 ◽  
Author(s):  
Dhanaji V. Jawale ◽  
Devendra Wagare ◽  
Dinesh L. Lingampalle ◽  
Prashant D. Netankar
Keyword(s):  
Efficient Method ◽  
Sodium Methoxide ◽  
Room Temperature ◽  
Medicinal Chemistry ◽  
Guanidine Hydrochloride ◽  
Nucleophilic Attack ◽  
Efficient Catalyst ◽  
Enolic Form ◽  
Keto Esters ◽  
Derivatives Of

Background: 1,4-benzothiazine carboxylates show wide application in the field of medicinal chemistry. Therefore, we have designed convenient and efficient method for the synthesis of 1,4-benzothiazine carboxylates. Objective: Synthesis of 1,4-benzothiazine carboxylates and its guanidines by simple and facile method using efficient catalyst. Method: Derivatives of 1,4-benzothiazine carboxylates were synthesized by cyclocondensing β-keto esters with 2- aminobenzenethiols using CAN as a catalyst at room temperature. 1,4-benzothiazine caboxylate,condensed with guanidine hydrochloride in the presence of sodium methoxide in DMF to obtained new 3-substituted-l-4Hbenzo[b][1,4]thiazine-2-carboxyguanidines (88-91%). Results: All the products were obtained with good to excellent yields within 40 min. Here, CAN oxidizes aminothiophenol into disulfide and then nucleophilic attack of enolic form of β-ketoesters on the disulphide and 1, 4-benzothiazine acetates, were obtained with good yields. Conclusion: We have designed convenient and efficient method for the synthesis of 1,4-benzothiazine carboxylates. Most remarkable features of this cyclocondensation such as use of efficient catalyst and non-volatile solvent under mild reaction condition to obtained excellent yield.

Development of the room temperature protocol based on room temperature ionic liquids and surfactant ionic liquids for the synthesis of derivatives of 2-amino-thiazoles and thermo-physical analysis of the synthesized derivatives using TGA-DSC.

2020 ◽  
Vol 10 ◽  
Author(s):  
Chandrakant Sarode ◽  
Sachin Yeole ◽  
Ganesh Chaudhari ◽  
Govinda Waghulde ◽  
Gaurav Gupta
Keyword(s):  
Thermal Analysis ◽  
Heat Capacity ◽  
Ionic Liquids ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Room Temperature ◽  
Heat Capacity Data ◽  
General Strategy ◽  
Capacity Data ◽  
Derivatives Of

Aims: To develop an efficient protocol, which involves an elegant exploration of the catalytic potential of both the room temperature and surfactant ionic liquids towards the synthesis of biologically important derivatives of 2-aminothiazole. Objective: Specific heat capacity data as a function of temperature for the synthesized 2- aminothiazole derivatives has been advanced by exploring their thermal profiles. Method: The thermal gravimetry analysis and differential scanning calorimetry techniques are used systematically. Results: The present strategy could prove to be a useful general strategy for researchers working in the field of surfactants and surfactant based ionic liquids towards their exploration in organic synthesis. In addition to that, effect of electronic parameters on the melting temperature of the corresponding 2-aminothiazole has been demonstrated with the help of thermal analysis. Specific heat capacity data as a function of temperature for the synthesized 2-aminothiazole derivatives has also been reported. Conclusion: Melting behavior of the synthesized 2-aminothiazole derivatives is to be described on the basis of electronic effects with the help of thermal analysis. Additionally, the specific heat capacity data can be helpful to the chemists, those are engaged in chemical modelling as well as docking studies. Furthermore, the data also helps to determine valuable thermodynamic parameters such as entropy and enthalpy.

Reactions of 3-cyano-1-methylquinolinium methyl sulphate with some C-acids and with p-nitroaniline

1981 ◽  
Vol 46 (2) ◽  
pp. 503-505 ◽  
Author(s):  
Oldřich Kocián ◽  
Miloslav Ferles
Keyword(s):  
Sodium Methoxide ◽  
Ethyl Cyanoacetate ◽  
Derivatives Of

The action of malononitrile, ethyl cyanoacetate, dibenzoylmethane and/or p-nitroaniline on compound I in the presence of sodium methoxide gives rise to derivatives of 3-cyano-1-methyl-1,4-dihydroquinoline, II and III

Preparation of Chloro and Sulfanyl Derivatives of 1-(2-Deoxy-4-C-hydroxymethyl-α-L-threo-Pentofuranosyl)uracil

1997 ◽  
Vol 62 (7) ◽  
pp. 1114-1127 ◽  
Author(s):  
Hubert Hřebabecký ◽  
Jan Balzarini ◽  
Antonín Holý
Keyword(s):  
Nucleophilic Substitution ◽  
Hydrogen Chloride ◽  
Thionyl Chloride ◽  
Sodium Methoxide ◽  
Thioacetic Acid ◽  
Uracil Derivatives ◽  
Derivatives Of ◽  
Hiv 1

3'-Chloro and 3'-acetylsulfanyl derivatives of 1-(2-deoxy-4-C-hydroxymethyl-α-L-threo-pentofuranosyl)uracil were prepared by reaction of 2,3'-anhydro-1-{5'-O-benzoyl-4'-C-[(benzoyloxy)methyl]-2'-deoxy-α-L-erythro-pentofuranosyl}uracil (3) with hydrogen chloride and thioacetic acid, respectively. The reaction with hydrogen chloride gave a mixture of N-1 and N-3 substituted uracil derivatives 12 and 14. Reaction of 1-{3-O-benzoyl-4-C-[(benzoyloxy)methyl]-2-deoxy-α-L-threo-pentofuranosyl}uracil (7) with thionyl chloride and subsequent debenzoylation afforded 1-(4-C-chloromethyl-2-deoxy-β-D-erythro-pentofuranosyl)uracil (19). Nucleophilic substitution with lithium thioacetate, followed by deacylation, converted 1-{3-O-benzoyl-4-C-[(benzoyloxy)methyl]-2-deoxy-5-O-p-toluenesulfonyl-α-L-threo-pentofuranosyl}uracil (9) into 1-(2-deoxy-4-C-sulfanylmethyl-β-D-erythro-pentofuranosyl)uracil (21). The obtained thiols were oxidized with iodine or air to give 1,1'-[disulfandiylbis(2,3-dideoxy-4-hydroxymethyl-α-L-threo-pentofuranose-3,1-diyl]di(pyrimidine-2,4-(1H,3H)-dione) (17) and 1,1'-[disulfandiylbis(2,5-dideoxy-4-hydroxymethyl-α-L-threo-pentofuranose-5,1-diyl]di(pyrimidine-2,4(1H,3H)-dione) (22). Reaction of 1-{3-acetylsulfanyl-5-O-methanesulfonyl-4-C-[(benzoyloxy)methyl]-2,3-dideoxy-α-L-threo-pentofuranosyl)}uracil (24) with methanolic sodium methoxide afforded 1-(3,5-anhydro-2,3-dideoxy-4-C-hydroxymethyl-3-sulfanyl-α-L-threo-pentofuranosyl)uracil (25). The same reagent was used in the preparation of 1-(3,5-anhydro-2-deoxy-4-C-hydroxymethyl-α-L-threo-pentofuranosyl)uracil (26) from 1-{4-C-[(benzoyloxy)methyl]-2-deoxy-5-O-p-toluenesulfonyl-α-L-threo-pentofuranosyl}uracil (8). From the series of 4'-substituted 2'-deoxyuridine derivatives, synthesized in this study, solely the 4'-chloromethyl derivative 19 and the oxetane derivative 26 exhibited an appreciable activity against HIV-1 and HIV-2.

scholarly journals Synthesis and Prognosis of Anti-inflammatory Activity of 2-substituted 5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidine-4(3h)-one

2021 ◽  
Vol 7 (12) ◽  
pp. 25-33
Author(s):  
A. Chiriapkin ◽  
I. Kodonidi ◽  
A. Ivchenko ◽  
L. Smirnova
Keyword(s):  
Acetic Acid ◽  
Biological Activity ◽  
Dimethyl Sulfoxide ◽  
In Silico ◽  
Glacial Acetic Acid ◽  
Inflammatory Activity ◽  
Modified Method ◽  
Anti Inflammatory ◽  
Catalytic Addition ◽  
Derivatives Of

The article presents a modified method for the synthesis of 2-substituted 5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidine-4(3H)-one and the predict of their anti-inflammatory activity. The proposed method for obtaining tetrahydrothienopyrimidine derivatives is preparatively effective and simple. Their synthesis was carried out by heterocyclization of azomethine derivatives of 2-amino-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxamide in the medium of glacial acetic acid with the catalytic addition of dimethyl sulfoxide. Preliminary prognosis of anti-inflammatory activity in silico method allowed us to identify the most promising compounds. Of these, the 4b structure containing a 2-hydroxyphenyl fragment in the second position of pyrimidine-4(3H)-one may be of the greatest interest. It seems appropriate to further study the spectrum of biological activity of the studied compounds.

scholarly journals Synthesis and anticonvulsant activity of 6-methyl-2-((2-oxo-2-arylethyl)thio)pyrimidin-4(3 H)-one derivatives and products of their cyclization

Pharmacia ◽  
2019 ◽  
Vol 66 (3) ◽  
pp. 141-146
Author(s):  
Hanna Severina ◽  
Olga O. Skupa ◽  
Natalya I. Voloshchuk ◽  
Marharyta M. Suleiman ◽  
Victoriya A. Georgiyants
Keyword(s):  
Sulphuric Acid ◽  
Anticonvulsant Activity ◽  
Sodium Methoxide ◽  
Structure Activity ◽  
Phenacyl Bromides ◽  
Pharmacological Screening ◽  
High Yields ◽  
Derivatives Of

The alkylation of 6-methyl-2-thioxo-2,3-dihydro-1H-pyrimidine-4-one phenacyl bromides under different conditions was investigated. It was found that during the reaction in the medium of DMF/K2CO3 a mixture of 2-(2-aryl-2-oxoethyl)thio-6-methyl-pyrimidine-4(3H)-one and 3-hydroxy-3-aryl-7-methyl-2,3-dihydro-5H-thiazolo[3,2-a]pyrimidine-5-one was formed. The holding of the resulting mixture in the concentrated sulphuric acid leads to the formation of cyclization products - derivatives of 3-aryl-7-methyl-5H-thiazolo[3,2-a]pyrimidin-5-one with high yields. Individual S-alkylated derivatives – 2-(2-aryl-2-oxoethyl)thio-6-methyl-pyrimidine-4(3H)-one - were obtained by reacting in methanol in the presence of sodium methoxide. Pharmacological screening of synthesized compounds for anticonvulsant activity on the model of pentylenetetrazole seizures in rats was carried out and some regularity “structure-activity” was established.

Unterscheidung von Stickstoff- und Phosphor-Inversion, Rotation um die N-P-Bindung und Ligandenaustausch am Phosphor

1968 ◽  
Vol 23 (6) ◽  
pp. 759-766 ◽  
Author(s):  
D. Imbery ◽  
H. Friebolin
Keyword(s):  
Low Temperatures ◽  
Room Temperature ◽  
Nitrogen Inversion ◽  
Kinetic Processes ◽  
Derivatives Of

A large number of aminophosphines were prepared to study the kinetic processes. It could be shown that at room temperature there is rapid nitrogen-inversion but slow phosphorous-inversion. At higher temperatures ( + 80 °C), a rapid chlorine-exchange takes place with inversion of configuration at phosphorous. At low temperatures ( — 80 °C), rotation around the N-P-bond was slow. A dependence of the barrier of rotation on the size of the substituents could be recognized. It is possible that pπ-dπ-bonding is partially responsible for the relatively high barrier of rotation compared with derivatives of ethane and hydrazine.

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