Indolizines. III. Studies on the acylative cyclization of stabilized Methylene-1,2-dihydropyridines. A novel synthesis of 3-phenyl-1,2-phthaloylindolizines

1972 ◽  
Vol 25 (7) ◽  
pp. 1549 ◽  
Author(s):  
I Dainis
Keyword(s):  
Acetic Anhydride ◽  
Mass Spectra ◽  
Benzyl Chloride ◽  
Reaction Medium ◽  
Phenacyl Bromide ◽  
Ethyl Chloroformate ◽  
Novel Synthesis ◽  
Aqueous Base

Cyclization of l-benzyl-2-ethoxycarbonylmethylene-1,2-dihydropyridine in acetic anhydride is shown to depend on the basicity of the reaction medium. The reaction between activated 2-methylpyridinium salts and ethyl chloroformate in aqueous base has provided a novel synthesis of 2-ethoxycarbonyl-methylene-l,2-dihydropyridines. Nass spectra of four 2-methylene-l,2-dihydropyridines are presented together with N.M.R. evidence for their 2-E configuration. Pyrophthalone (15) reacted with benzyl chloride in boiling nitrobenzene to give 2-benzylpyrophthalone. With phenacyl bromide, pyrophthalone gave 3-phenyl-1,2-phthaloylindolizine (6-phenylbenzo[f]pyrido[1,2-a]isoindole-7,12-dione) rather than the 3-benzoylindolizine (18). Quinophthalone reacted similarly, and the formation of both phthaloylindolizines has been attributed to a novel rearrangement of the 2-phenacylindan-l,3-dione system in the intermediate, alkylated products. Mass spectra of both phthalones and three phthaloylindolizines are presented.

scholarly journals Keggin-Type Heteropolyacid for Ring-Opening Polymerization of Cyclohexene Oxide: Molecular Weight Control

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Ahmed Aouissi ◽  
Zeid Abdullah Al-Othman ◽  
Abdurrahman Salhabi
Keyword(s):  
Molecular Weight ◽  
Reaction Time ◽  
Acetic Anhydride ◽  
Ring Opening ◽  
Weight Control ◽  
Reaction Medium ◽  
Resonance Spectroscopy ◽  
Cyclohexene Oxide ◽  
Scanning Calorimetry ◽  
Catalyst Amount

Polymerization of 1,2-cyclohexene oxide (CHO) in dichloromethane was catalyzed by 12-tungstophosphoric acid (H3PW12O40·13H2O) as a super solid acid. The effect of polymerization parameters such as reaction time, temperature, and catalyst amount was investigated. The effect of acetic anhydride as a ring-opening agent was also investigated. The resulting poly(1,2-cyclohexene oxide) (PCHO) was characterized by Fourier transform infrared (FTIR), nuclear magnetic resonance spectroscopy (1HNMR), gel-permeation chromatography (GPC), and differential scanning calorimetry (DSC). It has been found that the PCHO prepared over H3PW12O40·13H2O has a stereoregularity higher than that prepared over clay and Aluminium alkoxide catalysts. TheTgvalue obtained is due to the microstructure but not to molecular weight. The yield and the molecular weight of the polymer depend strongly on the reaction conditions. Molecular weights can be readily controlled by changing reaction temperature, reaction time, and catalyst amount. Contrary to most polymerization reactions, the molecular weight increases with the temperature increase. Addition of acetic anhydride to the reaction medium increased the yield threefold.

Reaction of thioamides with 2,3-dichloro-1,4-naphthoquinone. A novel synthesis of naphtho[2,3-d]thiazole-4,9-diones

1985 ◽  
Vol 50 (1) ◽  
pp. 71-79 ◽  
Author(s):  
A. S. Hammam ◽  
B. E. Bayoumy
Keyword(s):  
Aqueous Ethanol ◽  
Reaction Medium ◽  
Novel Synthesis

The reaction of thioamide II with 2,3-dichloro-1,4-naphthoquinone (I) in ethanol gave naptho[2,3-d]thiazole-4,9-diones (IV). The intermediates, 2-thioamido-3-chloro-1,4-naphthoquinones III were also isolated from the reaction medium and could be separately transformed to IV by further boiling in aqueous ethanol containing bicarbonate. The reaction of thiosemicarbazide with I under similar conditions gave naphtho[2,3-e]-2-amino-4H-1,3,4-thiadiazine-5,10-dione (VII).

A novel synthesis of 2,4,6-trithiaheptane and its conversion into 2,6-bis(methylthio)thiane. Spectral properties of some thiaalkanes

1981 ◽  
Vol 59 (2) ◽  
pp. 326-332 ◽  
Author(s):  
J. Stuart Grossert ◽  
Donald L. Hooper ◽  
William M. Neaves
Keyword(s):  
Long Range ◽  
Spectral Properties ◽  
Mass Spectra ◽  
Fragmentation Pathway ◽  
Coupling Constants ◽  
Spectral Studies ◽  
Proton Coupling ◽  
Novel Synthesis ◽  
C Nmr

2,4,6-Trithiaheptane (1a) has been prepared by lithium tetrahydridoaluminate reduction of the methiodide of 1,3,5-trithiane (2). Treatment of 1a with strong bases permitted formation of 3-alkylated derivatives (3) which could in turn be converted into diastereomeric mixtures of 3,5-dialkyl derivatives (4). A two-step alkylation of 1a with 1-bromo-3-chloropropane led to the formation of 2,6-bis(methylthio)thiane (5). Proton and 13C nmr spectral studies on these compounds, including the measurement of long-range carbon–proton coupling constants, are described; their mass spectra showed elimination of methanethiol as a characteristic major fragmentation pathway.

scholarly journals Consecutive reactions in an oleic acid and acetic anhydride reaction medium

2009 ◽  
Vol 111 (7) ◽  
pp. 723-729 ◽  
Author(s):  
Jerome Peydecastaing ◽  
Carlos Vaca-Garcia ◽  
Elisabeth Borredon
Keyword(s):  
Oleic Acid ◽  
Acetic Anhydride ◽  
Reaction Medium ◽  
Consecutive Reactions

scholarly journals Synthesis, characterization and Cytotoxicity Evaluation of New Compounds from Oxazol-5(4H)-ones and Oxazoles Class Containing 4-(4-Bromophenylsulfonyl)phenyl Moiety

2019 ◽  
Vol 70 (4) ◽  
pp. 1099-1107
Author(s):  
Theodora-Venera Apostol ◽  
Stefania-Felicia Barbuceanu ◽  
Octavian Tudorel Olaru ◽  
Constantin Draghici ◽  
Gabriel Saramet ◽  
...  
Keyword(s):  
Acetic Anhydride ◽  
Phosphorus Oxychloride ◽  
Spectral Studies ◽  
Ethyl Chloroformate ◽  
Anhydrous Aluminum Chloride ◽  
1H And 13C Nmr ◽  
Ft Ir ◽  
Concentrated Sulfuric Acid ◽  
New Compounds

Steiger N-acylation of a-alanine with 4-(4-bromophenylsulfonyl)benzoyl chloride led to 2-[4-(4-bromophenylsulfonyl)benzamido]propanoic acid. This compound underwent intramolecular cyclization in the presence of N-methylmorpholine and ethyl chloroformate or acetic anhydride to the corresponding saturated azlactone. Then acylaminoacylation of dry aromatic hydrocarbons with 2-[4-(4-bromophenylsulfonyl)phenyl]-4-methyloxazol-5(4H)-one or 2-[4-(4-bromophenylsulfonyl) benzamido ]propanoyl chloride in the presence of anhydrous aluminum chloride led to corresponding a-acylamino ketones. These new intermediates were heterocyclized under the action of phosphorus oxychloride or concentrated sulfuric acid in the presence of acetic anhydride to the corresponding oxazoles. The newly synthesized compounds were characterized by spectral studies (FT-IR, UV-Vis, MS, 1H- and 13C-NMR) and elemental analysis. The purity of the new compounds was evaluated by RP-HPLC. The experimental research regarding to the in vitro cytotoxic activity of the new compounds were performed using Daphnia magna bioassay.

scholarly journals Synthesis of 3-Oxo-α-ionol Ethyl Carbonate and its Conversion to Megastigmatrienones in Tobacco Smoke

2001 ◽  
Vol 19 (7) ◽  
pp. 339-343 ◽  
Author(s):  
H Yang ◽  
J Liu ◽  
K Li ◽  
X Yin ◽  
X Tan ◽  
...  
Keyword(s):  
Tobacco Smoke ◽  
Title Compound ◽  
Mass Spectra ◽  
Total Yield ◽  
Experimental Results ◽  
Ethyl Chloroformate

Abstract3-Oxo-α-ionol ethyl carbonate, a precursor of megastigmatrienones was prepared by reduction of α-ionone to α-ionol, followed by esterification with ethyl chloroformate and then by oxidation with t-butyl chromate. The total yield was about 23%. Infrared (IR) and mass spectra of this compound were determined. Upon smoking, cigarettes to which 0.002% by weight of the titled compound was added had an improved and more harmonious flavor. The smoke was sweeter and had a cleaner after taste. Experimental results suggest that the title compound added to the tobacco pyrolyzes to form megastigmatrienones during smoking.

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