Alkaloids of Schelhammera pedunculata (Liliaceae). II. Reactions of schelhammeridine

1969 ◽  
Vol 22 (10) ◽  
pp. 2203 ◽  
Author(s):  
SR Johns ◽  
JA Lamberton ◽  
AA Sioumis ◽  
H Suares
Keyword(s):  
Acetic Acid ◽  
Hydrochloric Acid ◽  
Acetic Anhydride ◽  
Absolute Configuration ◽  
Acetic Acid Solution ◽  
Acetyl Derivative ◽  
Major Product ◽  
Ring System ◽  
Single Isomer ◽  
Formed Product

Catalytic hydrogenation of schelhammeridine (I) in acetic acid solution gives demethoxydihydroschelhammeridine (II), 1,2,6α,7- tetrahydroschelhammeridine (III), dihydroschelhammeridine (IV), and a tetrahydro derivative (V), the formation of which involves cleavage of the C5-N9 bond. The major product from heating schelhammeridine with 10% aqueous hydrochloric acid is the alcohol (VIIa) with the configuration at C 3 opposite to that in schelhammeridine. Other products are the alcohol (IX) and two amino alcohols (Xa) and (XIIa) which have a diphenyl ring system formed by the aromatization of ring A. The compounds (Xa) and (XIIa) have been shown to be diastereoisomers with the same absolute configuration for the dissymmetric diphenyl system, but the opposite configuration at C 7, and they have been characterized as N-acetyl derivatives (Xb) and (XIIb) which have been assigned the respective configurations shown in (XX) and (XVIII). On heating with acetic anhydride, schelhammeridine is converted into the N,O-diacetyl compound (XVa) which on hydrolysis affords (XVb), the optical antipode of (Xb). All three stereo-isomeric N-acetylamides (Xb), (XIIb), and (XVb), are oxidized to the same optically inactive ketone (XI). A mechanism for the acetic anhydride reaction that explains the formation of only a single isomer is discussed, and it has been shown that the formation of (XVa), enantiomeric with (Xc), in this reaction necessarily involves inversion of the configuration of the diphenyl system in the first-formed product, which must be the O-acetyl derivative of (XVIII). It is concluded that amide alcohols (XVIII) and (XX) retain the configuration for the diphenyl system that would be predicted from the known absolute configuration of schelhammeridine, but that the initially formed O-acetyl derivative of (XVIII) obtained in the reaction with acetic anhydride is converted quantitatively at the temperature of the reaction mixture into the O-acetyl derivative of (XXI) by inversion of the diphenyl configuration.

Pyrimidine Derivatives and Related Compounds, V Synthesis of Some Isoxazolo [2,3-a] pyrimidines. A New Ring System

1977 ◽  
Vol 32 (3) ◽  
pp. 311-314 ◽  
Author(s):  
Mohamed Hilmy Elnagdi ◽  
Ezzat Mohamed Kandeel ◽  
Kamal Usef Sadek
Keyword(s):  
Acetic Acid ◽  
Hydrochloric Acid ◽  
Ethyl Acetoacetate ◽  
Pyrimidine Derivative ◽  
Ring System ◽  
The Other ◽  
Acid Mixture ◽  
Pyrimidine Derivatives ◽  
Benzoyl Isothiocyanates ◽  
Related Compounds

3-Amino-5-phenyl-4-phenylazoisoxazole (1) reacts with ethyl acetoacetate to yield the corresponding ethyl isoxazolylaminocrotonate derivative (2) which could be thermally cyclized into the isoxazolopyrimidine derivative (4). On the other hand, condensation of 1 with ethoxymethylenemalononitrile has resulted in the formation of the aminoethylene derivative (5).Compound 1 reacted with acrylonitrile to yield the isoxazolo[2,3-a]pyrimidine derivative (6). The latter was converted into the corresponding exo derivative (8) by the action of acetic acid-hydrochloric acid mixture.Compound 1 also reacted with methoxycarbonyl-, ethoxycarbomyl- and benzoyl isothiocyanates to yield the isoxazolylthioureas (10a, b) and (11), respectively. The reaction of 2 with acetic acid-hydrochloric acid and with phenylhydrazine is reported.

SYNTHESIS OF 2-, AND 3-NITROBENZANTHRONE VIA DIRECT NITRATION OF BENZANTHRONE WITH NITRIC ACID/ACETIC ACID

2019 ◽  
Vol 71 (1) ◽  
Author(s):  
Kefa K. Onchoke ◽  
Jorge J. Ojeda
Keyword(s):  
Acetic Acid ◽  
Nitric Acid ◽  
Acetic Anhydride ◽  
Standard Sample ◽  
Major Product ◽  
Fragmentation Patterns

Abstract Three mono-nitrobenzanthrone isomers (1-, 2-, and 3-nitrobenzanthrone; 1-, 2-, and 3-NBA) were synthesized by reacting benzanthrone (BA) with nitric acid (HNO3) in acetic anhydride at ice-cold conditions. The major product, 2-nitrobenzanthrone (2-NBA), was confirmed using GC-MS via comparisons with a standard sample. On the basis of the elution profiles and fragmentation patterns two other isomers formed were assigned to 1-, and 3-nitrobenzanthrone (1-, and 3-NBA). The average percent yields of 1-, 2-, and 3-NBA were 0.3 ± 0.1%, 10.5 ± 2.6 %, and 6.4 ± 1.3 %, respectively.

Study on Microcrystalline Chitin Cinnamon Nanoemulsion

2014 ◽  
Vol 525 ◽  
pp. 53-57 ◽  
Author(s):  
Xiao Qing Peng ◽  
Min Jie Wei ◽  
Liang Wang ◽  
Li Peng Gu
Keyword(s):  
Crystal Structure ◽  
Acetic Acid ◽  
Hydrochloric Acid ◽  
Molecular Crystal ◽  
Room Temperature ◽  
Isopropyl Alcohol ◽  
Acetic Acid Solution ◽  
Conductivity Data ◽  
Cinnamon Oil ◽  
Emulsification Process

To improve the miscibility of cinnamon oil with water, this study uses microcrystalline chitin as the surfactant to prepare cinnamon oil nanoemulsion. Firstly, use isopropyl alcohol and concentrated phosphoric to act with chitin, disperse molecular crystal structure of chitin, and then use hydrochloric acid for decalcification, and prepare microcrystalline chitin through centrifugation, washing, freezing and drying. Dissolve it in acetic acid solution as emulsification, and dissolve cinnamon oil in anhydrous ethanol, and mix both of which to obtain emulsion by drops. Judge the emulsification process and results of microcrystalline chitin on cinnamon oil through conductivity data. The conductivity decreases gradually to 0 from 1.4μS·cm-1. At room temperature, the solution is aqueous liquid without stratification and precipitation, but has good stability.

Preparation and Properties of Copolymer of Methacrylic Acid and Acrylamide onto Degraded Chitosan Initiated by HRP/H2O2/ACAC

2011 ◽  
Vol 80-81 ◽  
pp. 396-399 ◽  
Author(s):  
Sheng Hua Lv ◽  
Xiao Liang Yan ◽  
Rui Jun Gao
Keyword(s):  
Antimicrobial Activity ◽  
Acetic Acid ◽  
Reaction Time ◽  
Hydrochloric Acid ◽  
Methacrylic Acid ◽  
Acetic Acid Solution ◽  
Leather Industry ◽  
Low Viscosity ◽  
Acid Reaction ◽  
Good Uniformity

The chitosan was degraded by hydrochloric acid and the effects of concentration of chitosan, amount of hydrochloric acid, reaction temperature and reaction time on the viscosity of chitosan were investigated. The results showed that the degraded chitosan with low viscosity could be prepared when chitosan (wt 6%) was dissolved in acetic acid solution and hydrochloric acid (wt 3%) at 90°C for 6 h to decrease the viscosity from 7.52 mPa·s to 2.48 mPa·s. Then, a graft copolymer was synthesized by copolymerization of degraded chitosan with methacrylic acid (MAA) and acrylamide (AAM) by using horseradish peroxidase (HRP)/H2O2/acetylacetone (ACAC) as initiator. The structures of original chitosan, degraded chitosan and the copolymer were characterized by FTIR. The copolymer was applied to the leather industry as an amphoteric retanning agent. The applied results showed that the retanned leather had the merits of good uniformity fullness softness, strong selecting filling properties, good dyeing ability and antimicrobial activity.

THE ADDITION OF CARBOXYLIC ACIDS TO ACETYLENIC COMPOUNDS

1966 ◽  
Vol 44 (19) ◽  
pp. 2241-2244 ◽  
Author(s):  
J. DiPietro ◽  
W. J. Roberts
Keyword(s):  
Molecular Weight ◽  
Acetic Acid ◽  
Free Radical ◽  
Acetic Anhydride ◽  
Formic Acid ◽  
Propionic Acid ◽  
Major Product ◽  
Organic Peroxides ◽  
General Scope ◽  
Acetylenic Compounds

The free radical induced addition of acetic acid and its derivatives to olefins has been reported recently. As an extension of this reaction, the addition of acetic acid to acetylenic compounds was investigated.Adipic acid was found to be the major product of the reaction of excess acetic acid and acetylene at 110–120 °C under pressure in the presence of organic peroxides. A second oily acidic product with a molecular weight of about 300, not yet identified, was found to the extent of about 2 parts by weight to every 3 parts of adipic acid.Octen-3-oic acid and its anhydride were synthesized from hexyne-1 and excess acetic acid in the presence of organic peroxides. Acetic anhydride was substituted for acetic acid, with the net advantage that acetylene was more soluble in the solvent. The general scope of the reaction was expanded to include other transfer agents, such as acetone, formic acid, and propionic acid.

Nitration of 1-chloro-2,3-dimethylbenzene in acetic anhydride. Formation and rearomatization of adducts

1978 ◽  
Vol 56 (8) ◽  
pp. 1063-1068
Author(s):  
Alfred Fischer ◽  
Colin Campbell Greig
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Nitrous Acid ◽  
Major Product ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Nitro Derivatives ◽  
Subsequent Elimination ◽  
And Migration ◽  
Cis And Trans

Nitration of l-chloro-2,3-dimethylbenzene in acetic anhydride gives the cis and trans isomers of 3-chloro-4,5-dimethyl-4-nitrocyclohexa-2,5-dienyl acetate (29%) and l-chloro-2,3-dimethyl-4-nitro- (46%), -5-nitro- (5%), and -6-nitrobenzene (20%). In formic acid and acidified methanol, exchange of acetate for formate and methoxyl, respectively, occurs and the diastereoisomers of 3-chloro-4,5-dimethyl-4-nitrocyclohexa-2,5-dienyl formate and methyl ether, respectively, are formed. Rearomatization of each isomer of 3-chloro-4,5-dimethyl-4-nitrocyclohexa-2,5-dienyl acetate in acetic acid results in initial isomerization to form the pair of diastereoisomers and subsequent elimination of nitrous acid to form 3-chloro-4,5-dimethylphenyl acetate. In 25% trifluoroacetic acid in deuteriochloroform elimination of acetic acid and migration of the nitro group to form 1-chloro-2,3-dimethyl-4-nitro-benzene and a lesser amount of its 6-nitro isomer is the dominant reaction. In the presence of mesitylene the formation of the nitro derivatives is suppressed and 3′-chloro-2,4,4′,5′,6-pentamethylbiphenyl is obtained. It is proposed that cyclohexadienyl cations are significant intermediates in ail of the reactions. Pyrolysis of the adducts gives 1-chloro-2,3-dimethylbenzene as the major product.

AUTOXIDATION REACTIONS CATALYZED BY COBALT ACETATE BROMIDE

1965 ◽  
Vol 43 (5) ◽  
pp. 1306-1317 ◽  
Author(s):  
Allan S. Hay ◽  
Harry S. Blanchard
Keyword(s):  
Acetic Acid ◽  
Acid Solution ◽  
Carboxylic Acids ◽  
Atmospheric Pressure ◽  
Active Catalyst ◽  
Acetic Acid Solution ◽  
Cobalt Acetate ◽  
Major Product ◽  
High Yields

Cobalt acetate bromide in acetic acid solution is an extraordinarily active catalyst for the autoxidation of hydrocarbons. Carboxylic acids and ketones are readily prepared in high yields at moderate temperatures and at atmospheric pressure. In addition, benzylic and allylic groups can be converted to esters of the corresponding alcohols, and the oxidation of tetralin can be controlled to give either α-tetralone or 1,2-dihydronaphthalene as the major product. A mechanism for these reactions is postulated.

The oxidation of progesterone under GoAggIII conditions

1991 ◽  
Vol 56 (5) ◽  
pp. 984-990 ◽  
Author(s):  
Derek H. R. Barton ◽  
Dario Doller
Keyword(s):  
Hydrogen Peroxide ◽  
Acetic Acid ◽  
Acid Solution ◽  
Ferric Chloride ◽  
Picolinic Acid ◽  
Acetic Acid Solution ◽  
Major Product ◽  
Aqueous Hydrogen Peroxide ◽  
Ring Contraction ◽  
The Third

The oxidation of pregn-4-ene-3,20-dione (progesterone) by the GoAggIII system (aqueous hydrogen peroxide, ferric chloride, picolinic acid in pyridine-acetic acid solution) has been investigated. Two tri-keto derivatives were isolated and identified as pregn-4-ene-3,6,20-trione and pregn-4-ene-3,12,20-trione. The third major product isolated was identified as the unstable 5α-formyl-A-nor-pregnane-3,20-dione, which deformylated spontaneously to A-nor-5β-pregnane-3,20-dione. A mechanism for the A-ring contraction is proposed, based upon the participation of a carbon-Fe(V) intermediate.

Some Approaches to Viscometric Study of Chitosan in Acetic Acid Solution

2016 ◽  
Vol 10 (2) ◽  
pp. 135-139 ◽  
Author(s):  
Valentina Chernova ◽  
◽  
Angela Shurshina ◽  
Elena Kulish ◽  
Gennady Zaikov ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Acid Solution ◽  
Intrinsic Viscosity ◽  
Acetic Acid Solution ◽  
Conformational State ◽  
Macromolecular Coil ◽  
Degree Of Swelling ◽  
Current Value ◽  
Viscometric Study

Some ways of estimating the values of the intrinsic viscosity of chitosan were analyzed. It was shown that the method of Irzhak and Baranov for estimating the current value of the intrinsic viscosity allows to adequately estimates the conformational state of the macromolecular coil and its degree of swelling.

HPLC-UV Method for Determination of Famotidine from Pharmaceutical Products

2018 ◽  
Vol 69 (2) ◽  
pp. 297-299
Author(s):  
Adriana Nita ◽  
Delia Mirela Tit ◽  
Lucian Copolovici ◽  
Carmen Elena Melinte (Frunzulica) ◽  
Dana Maria Copolovici ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Quantitative Analysis ◽  
Linear Response ◽  
Mobile Phase ◽  
Acetic Acid Solution ◽  
Pharmaceutical Products ◽  
Quantification Limit ◽  
Validation Parameters ◽  
Hplc Analyses

The aim of this study was to develop and validate a rapid, accurate, and exact method for the quantitative determination of famotidine in pharmaceutical products. The HPLC analyses were performed by using a mobile phase containing methanol:1% acetic acid solution=30:7 (v/v), at a flow rate of 0.4 mL/min.The total time of the method was 10 min, and the retention time of famotidine was 4.16 min. The detection was evaluated at l=267 nm. The method has been validated by using different validation parameters. The linear response of the detector for famotidine peak area was observed at concentrations ranging from 0.1 to 0.0001 mg mL-1 , resulting in a correlation coefficient of 0.99998. The values of the detection limit and of the quantification limit are 0.00048 mg mL-1 and 0.00148 mg mL-1, respectively. The method proposed allowed accurate (with a relative error of less than 2%) and precise (RSD values less than 2.0%) determination of famotidine content in pharmaceutical products and can be used for its rapid quantitative analysis.

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