scholarly journals Synthesis of functionalized benzo[1,3]dioxin-4-ones from salicylic acid and acetylenic esters and their direct amidation

RSC Advances ◽  
2021 ◽  
Vol 11 (40) ◽  
pp. 24570-24574
Author(s):  
Rasmi P. Bhaskaran ◽  
Kalinga H. Nayak ◽  
Beneesh P. Babu

An efficient method for the synthesis of the active core 4H-benzo[d][1,3]dioxin-4-one followed by its direct room temperature amidation is reported.

2018 ◽  
Vol 15 (3) ◽  
pp. 380-387
Author(s):  
Xia Zhao ◽  
Xiaoyu Lu ◽  
Lipeng Zhang ◽  
Tianjiao Li ◽  
Kui Lu

Aim and Objective: Pyrazolone sulfones have been reported to exhibit herbicidal and antibacterial activities. In spite of their good bioactivities, only a few methods have been developed to prepare pyrazolone sulfones. However, the substrate scope of these methods is limited. Moreover, the direct sulfonylation of pyrazolone by aryl sulfonyl chloride failed to give pyrazolone sulfones. Thus, developing a more efficient method to synthesize pyrazolone sulfones is very important. Materials and Method: Pyrazolone, aryl sulphonyl hydrazide, iodine, p-toluenesulphonic acid and water were mixed in a sealed tube, which was heated to 100°C for 12 hours. The mixture was cooled to 0°C and m-CPBA was added in batches. The mixture was allowed to stir for 30 min at room temperature. The crude product was purified by silica gel column chromatography to afford sulfuryl pyrazolone. Results: In all cases, the sulfenylation products were formed smoothly under the optimized reaction conditions, and were then oxidized to the corresponding sulfones in good yields by 3-chloroperoxybenzoic acid (m-CPBA) in water. Single crystal X-ray analysis of pyrazolone sulfone 4aa showed that the major tautomer of pyrazolone sulfones was the amide form instead of the enol form observed for pyrazolone thioethers. Moreover, the C=N double bond isomerized to form an α,β-unsaturated C=C double bond. Conclusion: An efficient method to synthesize pyrazolone thioethers by iodine-catalyzed sulfenylation of pyrazolones with aryl sulfonyl hydrazides in water was developed. Moreover, this method was employed to synthesize pyrazolone sulfones in one-pot by subsequent sulfenylation and oxidation reactions.


Synlett ◽  
2021 ◽  
Author(s):  
Yadong Sun ◽  
Ablimit Abdukader ◽  
Yuhan Lu ◽  
Chenjiang Liu

AbstractA highly efficient method for the synthesis of 1,2,3-thiadiazoles has been developed by utilizing readily available tosylhydrazones and ammonium thiocyanate with ecofriendly EtOH as the solvent at room temperature. The reaction shows a wide scope of substrates and good functional-group tolerance. This protocol can be scaled up to a gram level and can be applied to coupling reactions with 4-(4-bromophenyl)-1,2,3-thiadiazole as the substrate.


Synthesis ◽  
2022 ◽  
Author(s):  
Dishu Zeng ◽  
Tianbao Yang ◽  
Niu Tang ◽  
Wei Deng ◽  
Jiannan Xiang ◽  
...  

A simple, mild, green and efficient method for the synthesis of 2-aminobenzamides was highly desired in organic synthesis. Herein, we developed an efficient, one-pot strategy for the synthesis of 2-aminobenzamides with high yields irradiated by UV light. 32 examples proceeded successfully by this photo-induced protocol. The yield reached up to 92%. The gram scale was also achieved easily. This building block could be applied in the preparation of quinazolinones derivatives. Amino acid derivatives could be employed smoothly at room temperature. Finally, a plausible mechanism was proposed.


2021 ◽  
Author(s):  
Hui Liu ◽  
Chao Liu ◽  
Shanyi Chen ◽  
Qihong Lai ◽  
Yulin Lin ◽  
...  

An efficient method for the direct oxidative lactonization of the C(sp3)–H bonds of benzyl via visible-light-induced photoredox catalysis. The metal-free protocol delivers diverse phthalides using O2 as the sole terminal oxidant at room temperature.


Author(s):  
Jakellinye Miranda ◽  
Suélen Braga de Andrade, Andressa Vighi Schiavon ◽  
Pedro Luis Panisson Kaltbach Lemos ◽  
Cláudia Simone Madruga Lima ◽  
Marcelo Barbosa Malgarim

Peach is a climacteric highly-perishable fruit whose post-harvest preservation relies largely on cold storage. The combination of the last with other technologies allows to extend the shelf life of this product. One alternative is the utilization of salicylic acid, a natural compound involved in many physiological phenomena such as resistance against diseases and ripening. Considering these facts, the objective of the present work was to evaluate the effect of pre-harvest application of salicylic acid solutions on the quality of ‘Chimarrita’ peaches during post-harvest cold storage. The experiment was conducted at the Federal University of Pelotas/RS, in the campus of Capão do Leão/RS - Brazil. The application of salicylic acid solutions was performed by direct pulverization on the fruits, 30 days prior to harvest. The concentrations were: 0,0 (control); 1,0; 1,5; and 2,0 mM. After harvest, the fruits were stored in a cold chamber at 1,0 ± 0,5°C and 85-90% RH, for 30 days. The analyses were performed at the following cold storage periods (plus 2 days at room temperature of 20°C to all treatments, in order to simulate commercialization conditions): 10 (+2) days; 20 (+2) days; e 30 (+2) days. The variables evaluated were: mass loss (%); flesh firmness (N); DA index; color (L, a*, b* and hue angle); wooliness incidence (%); rot incidence (%); total soluble solids (°Brix); pH; titrable acidity (% of organic acids); and ratio. The salicylic acid doses and/or the cold storage periods had significant effects on all the evaluated parameters. For most of the parameters analyzed, the intermediate dosis of 1mM (and also 1,5mM) of salicilic acid showed the most promising results. Therefore, the application of salicylic acid solutions 30 days prior to harvest is a technique which can be combined to cold storage in order to shift the quality and the shelf-life of ‘Chimarrita’ peaches.


2009 ◽  
Vol 6 (1) ◽  
pp. 156-160 ◽  
Author(s):  
Ji-Tai Li ◽  
Xian-Tao Meng

A convenient, mild and efficient method for oxidative cleavage of ketoximes to their parent carbonyl compounds with ammonium chlorochromate (ACC) / montmorillonite K10 in dichloromethane at room temperature is described


RSC Advances ◽  
2016 ◽  
Vol 6 (59) ◽  
pp. 54236-54240 ◽  
Author(s):  
Seyed Mohsen Sadeghzadeh

A green and efficient method for the synthesis of various triazolo[1,2-a]indazoletrione under mild conditions is reported, that making it a genuinely green protocol.


Synlett ◽  
2018 ◽  
Vol 29 (20) ◽  
pp. 2689-2692 ◽  
Author(s):  
Haifeng Wang ◽  
Xiangli Sun ◽  
Shuangling Zhang ◽  
Guanglu Liu ◽  
Chunjie Wang ◽  
...  

An efficient method for the synthesis of pyrazoles through a copper-catalyzed condensation reaction has been developed. The new catalytic system not only maintained a broad substrate scope but was also active under acid-free reaction conditions, overcoming the conventional requirement for an acid-catalyzed system. Furthermore, the copper catalyst enabled this reaction to be performed at room temperature and in a short reaction time.


2019 ◽  
Vol 44 (1-2) ◽  
pp. 72-79 ◽  
Author(s):  
Manjunatha M Ramaiah ◽  
Priya Babu Shubha ◽  
Pavan Kumar Prabhala ◽  
Nanjunda Swamy Shivananju

A facile and efficient method was developed for the preparation of a variety of aryl, heteroaryl, and alkyl N-sulfinyl imines using 1,8-diazabicyclo[5.4.0]undec-7-ene. In addition to tert-butanesulfinamide, the condensation is also effective with p-toluenesulfinamide. The reaction was performed at room temperature and produces the corresponding N-sulfinyl imines in excellent yields in the absence of acids, metals, and additives. This methodology is also useful for the preparation of N-sulfinyl imines on gram scale. A one-pot synthesis was developed using aryl and heteroaryl alcohols with both tert-butanesulfinamide and p-toluenesulfinamide at room temperature, resulting in the corresponding N-sulfinyl imines with good yields.


Sign in / Sign up

Export Citation Format

Share Document