One-Pot Synthesis of 2-Substituted Benzoxazoles Directly from Carboxylic Acids

2008 ◽  
Vol 61 (11) ◽  
pp. 881 ◽  
Author(s):  
Dinesh Kumar ◽  
Santosh Rudrawar ◽  
Asit K. Chakraborti
Keyword(s):  
Carboxylic Acids ◽  
Methanesulfonic Acid ◽  
Acid Chlorides ◽  
Double Bonds ◽  
Reaction Conditions ◽  
One Pot ◽  
Effective Catalyst ◽  
One Pot Synthesis ◽  
Highly Effective

Methanesulfonic acid has been found to be a highly effective catalyst for a convenient and one-pot synthesis of 2-substituted benzoxazoles by the reaction of 2-aminophenol with acid chlorides, generated in situ from carboxylic acids. Aryl, heteroaryl, and arylalkyl carboxylic acids provided excellent yields of the corresponding benzoxazoles. The reaction conditions were compatible with various substituents such as chloro, bromo, nitro, methoxy, cyclopentyloxy, phenoxy, thiophenoxy, and conjugated double bonds. Benzoxazole formation was found to be general with respect to substituted 2-aminophenols.

scholarly journals One-Pot Synthesis of Novel Multisubstituted 1-Alkoxyindoles

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1466
Author(s):  
Ye Eun Kim ◽  
Hyunsung Cho ◽  
Yoo Jin Lim ◽  
Chorong Kim ◽  
Sang Hyup Lee
Keyword(s):  
Alkyl Halide ◽  
The Novel ◽  
Reaction Conditions ◽  
One Pot ◽  
One Pot Synthesis ◽  
Consecutive Reactions ◽  
Intramolecular Condensation ◽  
Synthetic Sequence ◽  
Novel Target

Studies on a one-pot synthesis of novel multisubstituted 1-alkoxyindoles 1 and their mechanistic investigations are presented. The synthesis of 1 was successfully achieved through consecutive four step reactions from substrates 2. The substrates 2, prepared through a two-step synthetic sequence, underwent three consecutive reactions of nitro reduction, intramolecular condensation, and nucleophilic 1,5-addition to provide the intermediates, 1-hydroxyindoles 8, which then were alkylated in situ with alkyl halide to afford the novel target products 1. We optimized the reaction conditions for 1 focusing on the alkylation step, along with the consideration of formation of intermediates 8. The optimized condition was SnCl2·2H2O (3.3 eq) and alcohols (R1OH, 2.0 eq) for 1–2 h at 40 °C and then, base (10 eq) and alkyl halides (R2Y, 2.0 eq) for 1–4 h at 25–50 °C. Notably, all four step reactions were performed in one-pot to give 1 in good to modest yields. Furthermore, the mechanistic aspects were also discussed regarding the reaction pathways and the formation of side products. The significance lies in development of efficient one-pot reactions and in generation of new 1-alkoxyindoles.

Ethylenediamine: A Highly Effective Catalyst for One-Pot Synthesis of Aryl Nitroalkenes via Henry Reaction and Dehydration

2012 ◽  
Vol 30 (12) ◽  
pp. 2827-2833 ◽  
Author(s):  
Jianxin Yang ◽  
Jing Dong ◽  
Xia Lü ◽  
Qiang Zhang ◽  
Wei Ding ◽  
...  
Keyword(s):  
Henry Reaction ◽  
One Pot ◽  
Effective Catalyst ◽  
One Pot Synthesis ◽  
Highly Effective

Palladium-catalyzed one-pot cycloaddition reactions of thioureas with 3H-indol-3-ones generated in situ from 2-alkynyl arylazides: rapid and efficient access to imidazoloindolines

2020 ◽  
Vol 7 (21) ◽  
pp. 3480-3485
Author(s):  
Ping Li ◽  
Boyu Zhu ◽  
Yao Xu ◽  
Zhiqiang Zhou ◽  
Guiwen Hu ◽  
...  
Keyword(s):  
Cycloaddition Reactions ◽  
Reaction Conditions ◽  
One Pot ◽  
One Pot Synthesis ◽  
Efficient Access ◽  
Palladium Catalyzed

An efficient palladium-catalyzed one-pot synthesis of imidazoloindolines from 2-alkynyl arylazides under mild reaction conditions has been described.

2-Phenyl-2,3-dihydrobenzo[d]thiazole: A Mild, Efficient, and Highly Active in situ Generated Chemoselective Reducing Agent for the One-Pot Synthesis of 5-Monoalkylbarbiturates in Water

Synlett ◽  
2017 ◽  
Vol 29 (04) ◽  
pp. 477-482 ◽  
Author(s):  
Dibakar Deka ◽  
Subarna Kalita
Keyword(s):  
Reducing Agent ◽  
High Yield ◽  
Purification Process ◽  
Reaction Conditions ◽  
One Pot ◽  
One Pot Synthesis ◽  
Highly Active ◽  
The One ◽  
Operational Simplicity

A metal- and catalyst-free reductive alkylation protocol for the one-pot synthesis of 5-monoalkylbarbiturates from barbituric acids and aldehydes using the in situ generated chemoselective reducing agent 2-phenyl-2,3-dihydrobenzo[d]thiazole from 2-aminothiophenol and benzaldehyde is described. The notable advantages of the protocol are operational simplicity, mild reaction conditions, high yield, short reaction time, and simple workup and purification process which make it highly attractive.

Ultrasound-Assisted Synthesis of N-Acylcyanamides and N-Acyl-Substituted Imidazolones from Carboxylic Acids by Using Trichloroisocyanuric Acid/Triphenylphosphine

Synlett ◽  
2020 ◽  
Vol 31 (07) ◽  
pp. 703-707
Author(s):  
Wong Phakhodee ◽  
Dolnapa Yamano ◽  
Mookda Pattarawarapan
Keyword(s):  
Carboxylic Acids ◽  
Room Temperature ◽  
One Pot ◽  
One Pot Synthesis ◽  
Ultrasound Assisted ◽  
Trichloroisocyanuric Acid

A convenient ultrasound-assisted one-pot synthesis of N-acylcyanamides starting from readily available carboxylic acids and sodium cyanamide has been developed. Upon activation in the presence of trichloroisocyanuric acid (TCCA) and triphenylphosphine, a range of carboxylic acids was converted into N-acylcyanamides in good to excellent yields within 10 minutes at room temperature without base. Remarkably, N-acyl-substituted imidazolones were readily accessible through guanylation-cyclization of the in situ generated N-acylcyanamides.

scholarly journals “In Situ” Generated “HCl”: A Highly Efficient Catalyst for One-Pot Synthesis of 1H-Indazolo [1,2-b]phthalazine-1,6,11-triones and 1Hpyrazolo[1,2-b]phthalazine-5,10-diones under Solvent-Free Conditions

2017 ◽  
Vol 58 (2) ◽  
Author(s):  
Behrooz Maleki ◽  
Samaneh Sedigh Ashrafi
Keyword(s):  
Phthalic Anhydride ◽  
Solvent Free ◽  
Synthetic Route ◽  
Reaction Conditions ◽  
One Pot ◽  
Efficient Catalyst ◽  
Highly Efficient ◽  
One Pot Synthesis ◽  
Solvent Free Conditions

<p>The rapid and environmental synthetic route to produce 1<em>H</em>-indazolo[1,2-b] phthalazine-1,6,11-triones and 1<em>H</em>-pyrazolo[1,2-b]phthalazine-5,10-diones derivatives have been developed <em>via</em> multicomponent and one-pot reactions of various aldehydes, cyclic or acyclic 1,3-diketones with: <em>i)</em> phthalhydrazide or <em>ii)</em> phthalic anhydride-hydrazinium hydroxide using wet 2,4,6-trichlorotriazine (TCT) as catalyst under solvent-free conditions. Simple and mild reaction conditions, the use of a cheap catalyst and easy workup and isolation are notable features of this method.</p>

One-pot synthesis of primary amines from carboxylic acids through rearrangement of in situ generated hydroxamic acid derivatives

2016 ◽  
Vol 57 (48) ◽  
pp. 5304-5307 ◽  
Author(s):  
Yujiro Hoshino ◽  
Naoya Ohtsuka ◽  
Takuya Okada ◽  
Kiyoshi Honda
Keyword(s):  
Carboxylic Acids ◽  
Hydroxamic Acid ◽  
Primary Amines ◽  
One Pot ◽  
One Pot Synthesis ◽  
Hydroxamic Acid Derivatives
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