49619-44-5Relevant articles and documents
Size-Driven Inversion of Selectivity in Esterification Reactions: Secondary Beat Primary Alcohols
Mayr, Stefanie,Marin-Luna, Marta,Zipse, Hendrik
, p. 3456 - 3489 (2021/03/01)
Relative rates for the Lewis base-mediated acylation of secondary and primary alcohols carrying large aromatic side chains with anhydrides differing in size and electronic structure have been measured. While primary alcohols react faster than secondary ones in transformations with monosubstituted benzoic anhydride derivatives, relative reactivities are inverted in reactions with sterically biased 1-naphthyl anhydrides. Further analysis of reaction rates shows that increasing substrate size leads to an actual acceleration of the acylation process, the effect being larger for secondary as compared to primary alcohols. Computational results indicate that acylation rates are guided by noncovalent interactions (NCIs) between the catalyst ring system and the DED substituents in the alcohol and anhydride reactants. Thereby stronger NCIs are formed for secondary alcohols than for primary alcohols.
Organocatalytic Desymmetrisation of Fittig's Lactones: Deuterium as a Reporter Tag for Hidden Racemisation
Spránitz, Péter,Soregi, Petra,Botlik, Bence Béla,Berta, Máté,Soós, Tibor
, p. 1263 - 1272 (2019/02/26)
Highly enantioselective desymmetrisation of Fittig's lactones with alcohols is promoted by bifunctional cinchona squaramides. The reactions were carried out with monodeuterated methanol to detect possible hidden racemisation of the stereogenic centre. Current evidence suggests that racemisation was not a relevant process for most substrates; partial erosion of enantioselectivity was only detected with ortho -substituted aryl derivates. The resultant glutaric acid derivatives possess a scaffold that is common in natural products and the compounds are also useful chiral building blocks for further synthetic endeavours.
Synthesis, biological evaluation and docking study of a new series of di-substituted benzoxazole derivatives as selective COX-2 inhibitors and anti-inflammatory agents
Kaur, Avneet,Pathak, Dharam P.,Sharma, Vidushi,Wakode, Sharad
, p. 891 - 902 (2018/01/22)
A new series of substituted-N-(3,4-dimethoxyphenyl)-benzoxazole derivatives 13a–13p was synthesized and evaluated in vitro for their COX (I and II) inhibitory activity, in vivo anti-inflammatory and ulcerogenic potential. Compounds 13d, 13h, 13k, 13l and 13n exhibited significant COX-2 inhibitory activity and selectivity towards COX-2 over COX-1. These selected compounds were screened for their in vivo anti-inflammatory activity by carrageenan induced rat paw edema method. Among these compounds, 13d was the most promising analogs of the series with percent inhibition of 84.09 and IC50 value of 0.04 μM and 1.02 μM (COX-2 and COX-1) respectively. Furthermore, ulcerogenic study was performed and tested compounds (13d, 13h, 13k, 13l) demonstrated a significant gastric tolerance than ibuprofen. Molecular docking study was also performed with resolved crystal structure of COX-2 to understand the binding mechanisms of newly synthesized inhibitors in the active site of COX-2 enzyme and the results were found to be concordant with the biological evaluation studies of the compounds. These newly synthesized inhibitors also showed acceptable pharmacokinetic profile in the in silico ADME/T analyses.
Cu-MOF: An efficient heterogeneous catalyst for the synthesis of symmetric anhydrides: Via the C-H bond activation of aldehydes
Ahmadzadeh, Zahra,Mokhtari, Javad,Rouhani, Morteza
, p. 24203 - 24208 (2018/07/25)
In this paper, an efficient and straightforward synthetic approach for the preparation of a number of symmetric carboxylic anhydrides was reported using Cu2(BDC)2(DABCO) as an efficient heterogeneous catalyst via the C-H bond activation of aldehydes with excellent yields and simple work up. This C-H bond activation reaction appears simple and convenient, has a wide substrate scope and makes use of cheap, abundant, and easily available reagents. The Cu-MOF catalyst was recycled and reused four times without any loss of catalytic activity.
An investigation on practical synthesis of carboxylic acid derivatives using p-toluenesulfonyl chloride
Eskandari, Parvin,Kazemi, Foad
, p. 431 - 439 (2017/07/24)
Carboxylic acid derivatives are well recognized as important class of reagents frequently used in the preparation of a variety of fine or special chemicals such as amides, esters, peptides, drugs, and dyes. Although several methods were developed for the preparation of these compounds, many of them present difficulties, including low yield, high reaction temperature, harsh reaction conditions, tedious work-up, and incompatibility with scale-up. Methods: The synthesis of carboxylic anhydrides is developed through the reaction of carboxylic acids with TsCl in the presence of K2CO3 and acetonitrile as a solvent under ultrasound irradiation and conventional conditions. In addition, one-pot synthesis of acyl azides was carried out in the presence of produced carboxylic anhydrides and the addition of sodium azide under identical condition. Results: A series of carboxylic anhydrides and acyl azides were synthesized using TsCl under ultrasound irradiation and conventional stirring with simple procedure, mild reaction conditions, high yields, and scale-up ability without any restriction. In most cases, the reaction under ultrasound irradiation was better in both yields and the reaction times compared to the conventional method. Conclusion: A convenient method has been developed for the preparation of carboxylic anhydrides and acyl azides under ultrasound irradiation and conventional stirring. The present method is practical and a highly effective alternative for previous reports. The major advantages of this method are: (i) simplicity of the procedure (ii) high yields and high purity of product (iii) scale-up capacity without considerable limitation in conventional system. Under ultrasound irradiation short reaction times as compared to conventional method are observed; yields are comparable to or better than conventional method.
Light-enabled synthesis of anhydrides and amides
Mccallum, Terry,Barriault, Louis
, p. 2874 - 2878 (2015/03/30)
Recently, we have demonstrated that the photogeneration of Vilsmeier-Haack reagents is possible using only dimethylformamide (DMF) and tetrabromomethane (CBr4) in the bromination of alcohols. Extending these findings to carboxylic acid substrates has produced a mild and facile approach to the in situ formation of symmetric anhydrides, which were conveniently converted to amide derivatives in a one-pot process. The efficient protocols discussed herein are marked by use of UVA LEDs (365 nm), which have reduced the reaction times and come with a low setup cost.
A mild, clean, and simple synthesis of symmetrical carboxylic anhydrides from carboxylic acides using a polymer supported tosyl chloride
Zarchi, M. A. Karimi,Mirjalili,Kahrizsangi, Z. Shamsi,Tayefi
experimental part, p. 455 - 460 (2010/08/20)
The use of polymeric reagents simplifies routine acylation of carboxylic acid because it eliminates the traditional purification. We describe the use of readily available cross-linked poly(4-vinylpyridine) supported tosyl chloride, [P4VP].TsCl, in the suspended solution phase synthesis of symmetrical anhydrides from carboxylic acids in the presence of K2CO3 in high yields and purity. The products can be obtained by filtration and evaporation of the solvent.
Mild and efficient synthesis of carboxylic acid anhydrides from carboxylic acids and triazine coupling reagents
Kaminski, Zbigniew J.,Kolesinska, Beata,Malgorzata, Marcinkowska
, p. 3349 - 3358 (2007/10/03)
Anhydrides of carboxylic acids were obtained in 53%-95% yield by treatment of appropriate carboxylic acids with 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT) or 2,4-dichloro-6-methoxy-1,3,5-triazine (DCMT) in the presence of N-methylmorpholine. It has been proved that synthesis proceeds via triazine active esters 3a,b, which are able to acylate carboxylate anion but not less nucleophilic carboxylic acid.
Facile and Efficient Syntheses of Carboxylic Anhydrides and Amides Using (Trimethylsilyl)ethoxyacetylene
Kita, Yasuyuki,Akai, Shuji,Ajimura, Naomi,Yoshigi, Mayumi,Tsugoshi, Teruhisa,et al.
, p. 4150 - 4158 (2007/10/02)
(Trimethylsilyl)ethoxyacetylene, a stable and easy-handling reagent, serves as an excellent dehydrating agent for the synthesis of carboxylic anhydrides and amides from the corresponding carboxylic acids.By means of this reagent, various types of acid-sensitive carboxylic anhydrides and amides were obtained almost in quantative yields.Twenty-two examples of carboxylic anhydrides and 12 examples of amides were presented.
A MILD AND FACILE SYNTHESIS OF CARBOXYLIC ANHYDRIDES
Kita, Y.,Akai, S.,Yoshigi, M.,Nakajima, Y.,Yasuda, H.,Tamura, Y.
, p. 6027 - 6030 (2007/10/02)
Reaction of carboxylic acids with trimethylsilylethoxyacetylene in an inert solvent under mild conditions affords the corresponding carboxylic anhydrides in almost quantitative yields.
