scholarly journals A Facile and Efficient Method for Catalytic Acetylation of Alcohols with Acetic Acid

2010 ◽  
Vol 31 (12) ◽  
pp. 3870-3871 ◽  
Author(s):  
Anindita Dewan ◽  
Utpal Bora ◽  
Dilip Kumar Kakati
Keyword(s):  
Author(s):  
Xue Yang ◽  
Yongling Liu ◽  
Tao Chen ◽  
Nana Wang ◽  
Hongmei Li ◽  
...  

Abstract Separation of natural compounds directly from the crude extract is a challenging work for traditional column chromatography. In the present study, an efficient method for separation of three main compounds from the crude extract of Dracocephalum tanguticum has been successfully established by high-speed counter-current chromatography (HSCCC). The crude extract was directly introduced into HSCCC by using dimethyl sulfoxide as cosolvent. Ethyl acetate/n-butyl alcohol/0.3% glacial acetic acid (4: 1: 5, v/v) system was used and three target compounds with purity higher than 80% were obtained. Preparative HPLC was used for further purification and three target compounds with purity higher than 98% were obtained. The compounds were identified as chlorogenic acid, pedaliin and pedaliin-6″-acetate.


Synlett ◽  
2017 ◽  
Vol 28 (18) ◽  
pp. 2483-2488 ◽  
Author(s):  
Bo Jiang ◽  
Guigen Li ◽  
Shuo Qiao ◽  
Jianbin Wu ◽  
Junming Mo ◽  
...  

A series of new chiral N-phosphinyl β-enamino esters and amides were successfully prepared with excellent Z-stereoselectivity (Z/E > 99:1 in nearly all cases). Group-assisted purification chemistry proved to be an efficient method for the asymmetric reduction of the resulting β-enamino esters/amides to give enantiopure β-amino esters/amides. The asymmetric reduction can be controlled efficiently by using a combination of sodium cyanoborohydride and acetic acid.


2010 ◽  
Vol 6 ◽  
Author(s):  
Vsevolod V Komissarov ◽  
Anatoly M Kritzyn ◽  
Jouko J Vepsäläinen

A novel one-pot method was developed for the synthesis of the title compounds starting from 4-chloro-1-aryl-1-butanones 1, phosphorus trichloride and acetic acid. The end products 2 were obtained in 20–94% yield. The cyclization step under acidic conditions probably occurs as a result of anchimeric assistance of the phosphonic acid group.


2019 ◽  
Vol 21 (4) ◽  
pp. 13-19
Author(s):  
Luwei Fang ◽  
Minglei Tian ◽  
Liangwen Lin ◽  
Kyung Ho Row

Abstract Multiphase extraction (MPE) was applied as a developed, convenient and efficient method in separation of ephedrine from Pinellia ternata. Firstly, in order to increase the adsorption efficiency, bionic liquid-modified polymer was created. Comparing the effects of all sorbents under variables conditions, the highest amount of 5.8 mg/g can be adsorbed on dual imidazole ionic liquid modified polymer (Im-Im-Poly) in methanol/water (70:30, v/v) solution at 25°C within 30.0 min. Then the Im-Im-Poly was applied in MPE, after 7 times repetition of extraction, around 1.0 mg/g of ephedrine from Pinellia ternata was detected. After washing by water, ethanol and methanol, and elution by methanol/acetic acid (99.0:1.0, v/v), ephedrine was successfully separated.


Synlett ◽  
2018 ◽  
Vol 29 (17) ◽  
pp. 2316-2320 ◽  
Author(s):  
Takayuki Yakura ◽  
Tomoya Fujiwara ◽  
Hideyuki Nishi ◽  
Yushi Nishimura ◽  
Hisanori Nambu

[4-Iodo-3-(isopropylcarbamoyl)phenoxy]acetic acid was developed as a highly reactive and easily separable catalyst for the oxidative cleavage of tetrahydrofuran-2-methanols to γ-lactones in the presence of Oxone® (2KHSO5·KHSO4·K2SO4) as the co-oxidant. The reactivity of this new catalyst was considerably greater than that of our previously reported catalyst, 2-iodo-N-isopropylbenzamide. The new catalyst and product were easily separated by only liquid–liquid separation without chromatography. In addition, using a mixture of nitromethane and N,N-dimethylformamide as the solvent and heating enabled a low catalyst loading, a short reaction time, and high product yield. Oxidative cleavage using the new catalyst can be used as a practical and efficient method for synthesizing γ-lactones.


2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Mashooq A. Bhat ◽  
Mohamed A. Al-Omar ◽  
Ahmed M. Naglah ◽  
Abdullah Al-Dhfyan

A new series of novel Biginelli compounds, 5-benzoyl-substituted phenyl-3,4-dihydropyrimidin-2(1H)-one-1H-isoindole-1,3(2H)-dione (1−10), were synthesized from enaminone, 2-{4-[(2E)-3-(dimethylamino)prop-2-enoyl]phenyl}-1H-isoindole-1,3(2H)-dione (IV), which was synthesized by refluxing 2-(4-acetylphenyl)-1H-isoindole-1,3(2H)-dione (III), with dimethylformamide-dimethylacetal (DMF-DMA) without solvent for 12 h. The compound 2-(4-acetylphenyl)-1H-isoindole-1,3(2H)-dione (III) was obtained by reacting phthalic anhydride (I) with para-aminoacetophenone (II) in glacial acetic acid for 2 h. The dihydropyrimidinone derivatives containing phthalimide moiety (1–10) were obtained by reacting enaminone, 2-{4-[(2E)-3-(dimethylamino) prop-2-enoyl] phenyl}-1H-isoindole-1,3(2H)-dione (IV), with urea and different substituted benzaldehydes in the presence of glacial acetic acid for 3 h. Simple and efficient method was employed to synthesize the dihydropyrimidinone derivatives containing phthalimide moiety. Structures of all the synthesized compounds were characterized by spectroscopic methods.


2005 ◽  
Vol 7 (9) ◽  
pp. 1723-1724 ◽  
Author(s):  
Stella Kokinaki ◽  
Leondios Leondiadis ◽  
Nikolas Ferderigos
Keyword(s):  

2019 ◽  
Vol 16 (11) ◽  
pp. 911-914
Author(s):  
De-Jun Zhou ◽  
Yang-Yang Zhai ◽  
Ling-Pu Meng ◽  
Wei-Wei Song ◽  
Xiao Liu ◽  
...  

This study introduces a concise and efficient method for preparing diacetoxyiodoarenes from the corresponding iodoarenes. In the presence of acetic anhydride, iodoarenes were oxidized to diacetoxyiodoarenes by sodium perborate in acetic acid under argon protection at 55°C in ideal yields. Through this method, 10 diacetoxyiodoarenes were obtained smoothly.


2011 ◽  
Vol 8 (2) ◽  
pp. 535-540 ◽  
Author(s):  
Masoumeh Tabatabaee ◽  
Majid M. Heravi ◽  
Mahboubeh Sharif ◽  
Fatemeh Esfandiyari

Reaction ofN-aminorhodanine with various aldehydes under classical heating (in various solvents, using hydrochloric acid or acetic acid as catalyst) or by using Al2O3under microwave irradiation in solventless system led to the corresponding imines (2or3). All the compounds have been characterized by elemental analyses, NMR and IR spectroscopy. Results indicate that treatment ofN-aminorhodanine with aldehydes in acetonitrile as solvent or under solventless system led to the corresponding imines(2a-2e), while reactions were performed in solvent such as methanol3a-3ewas formed as products of ring cleavage and imination.


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