Highly selective mono-N-benzylation and amidation of amines with alcohols or carboxylic acids using the Ph2PCl/I2/imidazole reagent system

2012 ◽  
Vol 90 (6) ◽  
pp. 498-509 ◽  
Author(s):  
Najmeh Nowrouzi ◽  
Mohammad Zareh Jonaghani
Keyword(s):  
Carboxylic Acids ◽  
Molecular Iodine ◽  
Basic Solution ◽  
Reaction Conditions ◽  
Chromatographic Methods ◽  
Excellent Selectivity

Chlorodiphenylphosphine, imidazole, and molecular iodine in refluxing dichloromethane are used for the efficient preparation of amides under mild reaction conditions. This reagent system also shows excellent selectivity for mono-N-alkylation of amines with alcohols. In this system, the resulting phosphorus byproduct (diphenylphosphinic acid) is easily removed by extraction using an aqueous basic solution in the workup processes, which avoids the tedious and time-consuming chromatographic methods.

scholarly journals NaIO4/Br- as a mild system for the oxidation of 1-methyl-anthra-9,10-quinones

2015 ◽  
Author(s):  
Marcin Cybulski ◽  
Adam Formela ◽  
Katarzyna Sidoryk ◽  
Olga Michalak ◽  
Anna Rosa ◽  
...  
Keyword(s):  
High Pressure ◽  
Carboxylic Acids ◽  
Scale Up ◽  
Lithium Bromide ◽  
Cost Effective ◽  
Building Blocks ◽  
Multidrug Resistant ◽  
Resistant Cell ◽  
Direct Oxidation ◽  
Reaction Conditions

One of the anthraquinone classes comprises compounds with a carbonyl group. These natural or synthetic anthraquinones find their application as building blocks in the synthesis of the compounds with a biological activity. Recently, 4-substituted anthra-9,10-quinone-1-carboxylic acids (2) have been used as key intermediates in the synthesis of patented compounds (3) with anticancer activity against multidrug resistant cell lines. Although 2,7-dihydro-3H-dibenz[de,h]cinnolin-3,7-diones (3) were successfully synthetized in a small laboratory scale, several problems were observed during the preparation of their acid intermediates (2) in a multi-gram scale. The known methods for the preparation of 2 are based on the oxidation of the methyl group in anthra-9,10-quinones (1). The most common are: the oxidation with the diluted nitric acid under high pressure in a sealed tube at the temperature of 195-220 oC, the oxidation in nitrobenzene by passing chlorine gas through the reaction mixture at the temperature of 160-170 oC or in a presence of the fuming sulphuric acid. The mentioned methods require aggressive reagents and specific reaction conditions including high pressure and temperature. Thus, there was a need to find a new efficient, cost-effective and reproducible synthetic method of preparation of 2. While searching literature it was found that the direct oxidation of alkylarenes mediated by the sodium periodate/lithium bromide combination produces benzyl acetates throughout benzyl bromides in the acetic acid, or benzylic acids in the diluted inorganic acid. Based on these results we examined a variety of reaction conditions with or without the bromine source and the oxidizing anion. As a result, a novel procedure for the preparation of highly pure 4-substituted anthra-9,10-quinone-1-carboxylic acids (HPLC > 99.5%) using oxidizing anion/ brominating reagent system was developed. It enabled 2 isolation by the simple filtration of the reaction mixture and was applied in the scale-up of 2,7-dihydro-3H-dibenz[de,h]cinnolin-3,7-dione derivatives.

Efficient synthesis of pyrido[2,3-d]pyrimidine-7-carboxylic acids catalyzed by a TiO2/SiO2 nanocomposite in aqueous media at room temperature

2018 ◽  
Vol 73 (9) ◽  
pp. 641-645 ◽  
Author(s):  
Sepehr Sadegh-Samiei ◽  
Shahrzad Abdolmohammadi
Keyword(s):  
Heterogeneous Catalyst ◽  
Carboxylic Acids ◽  
Room Temperature ◽  
Aqueous Media ◽  
Reaction Times ◽  
Molar Ratio ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
Moderate Reaction ◽  
Recyclable Heterogeneous Catalyst

AbstractA novel and efficient synthesis of eight 5-aryl-1,3-dimethyl-2,4-dioxo-1,2,3,4,5,8-hexahydropyrido[2,3-d]pyrimidine-7-carboxylic acids using a TiO2/SiO2 nanocomposite with a molar ratio of 1:1 as a recyclable heterogeneous catalyst is described. The desired products, five of which are new, are formed in short reaction times (2–3 h) with high to excellent yields (94%–98%) under very moderate reaction conditions (room temperature, aqueous media).

Trichloroisocyanuric Acid Mediated High-Yielding Synthesis of N-Acylbenzotriazoles under Mild Reaction Conditions

Synthesis ◽  
2019 ◽  
Vol 51 (10) ◽  
pp. 2183-2190 ◽  
Author(s):  
Mala Singh ◽  
Anoop Singh ◽  
Nidhi Mishra ◽  
Anand Agrahari ◽  
Vinod Tiwari
Keyword(s):  
Carboxylic Acids ◽  
Reaction Path ◽  
Reaction Conditions ◽  
Salient Features ◽  
Trichloroisocyanuric Acid

N-Acylbenzotriazoles are achieved in good yields from the corresponding carboxylic acids by using only 0.35 equivalent of trichloroisocyanuric acid and 1.2 equivalents of PPh3. The salient features of the developed reaction path include an economic, facile, base-free, and equally useful method in milligram to gram scale.

Diiodine–Triethylsilane System: Reduction of N-Sulfonyl Aldimines to N-Alkylsulfonamides

Synlett ◽  
2020 ◽  
Author(s):  
Jin Jiang ◽  
Lili Xiao ◽  
Yu-Long Li
Keyword(s):  
Practical Method ◽  
Molecular Iodine ◽  
Reaction Conditions ◽  
System Reduction

AbstractBecause molecular iodine and hydrosilanes are stable to both air and moisture, reactions using these reagents are easy to operate and require mild reaction conditions. Molecular iodine and a hydrosilane were used to reduce N-sulfonyl aldimines to the corresponding N-alkylsulfonamides. This transformation is a practical method for the synthesis of N-alkylsulfonamides.

scholarly journals Manganese-mediated reductive functionalization of activated aliphatic acids and primary amines

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhan Li ◽  
Ke-Feng Wang ◽  
Xin Zhao ◽  
Huihui Ti ◽  
Xu-Ge Liu ◽  
...  
Keyword(s):  
Carboxylic Acids ◽  
Late Stage ◽  
Materials Science ◽  
Reaction Pathway ◽  
Chemical Conversion ◽  
Primary Amines ◽  
Mechanistic Studies ◽  
Reaction Conditions ◽  
Aliphatic Acids ◽  
Redox Active

Abstract Alkyl carboxylic acids as well as primary amines are ubiquitous in all facets of biological science, pharmaceutical science, chemical science and materials science. By chemical conversion to redox-active esters (RAE) and Katritzky’s N-alkylpyridinium salts, respectively, alkyl carboxylic acids and primary amines serve as ideal starting materials to forge new connections. In this work, a Mn-mediated reductive decarboxylative/deaminative functionalization of activated aliphatic acids and primary amines is disclosed. A series of C-X (X = S, Se, Te, H, P) and C-C bonds are efficiently constructed under simple and mild reaction conditions. The protocol is applicable to the late-stage modification of some structurally complex natural products or drugs. Preliminary mechanistic studies suggest the involvement of radicals in the reaction pathway.

Molecular-Iodine-Promoted Synthesis of Dihydrobenzofuran-3,3-dicarbonitriles through a Novel Rearrangement

Synlett ◽  
2019 ◽  
Vol 30 (03) ◽  
pp. 293-298
Author(s):  
Nagaraju Medishetti ◽  
Ashok Kale ◽  
Jagadeesh Nanubolu ◽  
Krishnaiah Atmakur
Keyword(s):  
Molecular Iodine ◽  
Basic Medium ◽  
Reaction Conditions ◽  
Simple Reaction

The title compounds were synthesized from 5,5-dimethyl­cyclohexane-1,3-dione, benzaldehyde, and malononitrile promoted by molecular iodine in basic medium via 2-amino-7,7-dimethyl-5-oxo-4-phenyl-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile, by a novel protocol. The protocol involves a novel rearrangement in which the 4H-chromene fragment dissociates to a cyclopropane moiety and rearranges to the five-membered compound 6,6-dimethyl-4-oxo-2-phenyl-4,5,6,7-tetrahydrobenzofuran-3,3(2H)-dicarbonitrile. Simple reaction conditions, excellent yields, and high compatibility are the advantages of this protocol.

ChemInform Abstract: Influence of the Reaction Conditions in the N-Alkylation of Acridone-2-carboxylic Acids.

ChemInform ◽  
2010 ◽  
Vol 32 (45) ◽  
pp. no-no
Author(s):  
Lisbet Xuarez Marill ◽  
Rolando F. Pellon Comdom ◽  
Miriam Mesa Hernandez
Keyword(s):  
Carboxylic Acids ◽  
Reaction Conditions

scholarly journals Reaction of Carboxylic Acids with Vinyl Ethers under Solvent-free Conditions Using Molecular Iodine as a Catalyst

2013 ◽  
Vol 62 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Yohko Hanzawa ◽  
Yoshio Kasashima ◽  
Kahoko Hashimoto ◽  
Tatsuhiro Sasaki ◽  
Keita Tomisaki ◽  
...  
Keyword(s):  
Carboxylic Acids ◽  
Molecular Iodine ◽  
Solvent Free ◽  
Vinyl Ethers ◽  
Solvent Free Conditions

Facile and direct synthesis of symmetrical acid anhydrides using a newly prepared powerful and efficient mixed reagent

2015 ◽  
Vol 69 (3) ◽  
Author(s):  
Hamed Rouhi-Saadabad ◽  
Batool Akhlaghinia
Keyword(s):  
Carboxylic Acids ◽  
Room Temperature ◽  
Low Cost ◽  
Direct Synthesis ◽  
Reaction Conditions ◽  
Experimental Procedure ◽  
Short Reaction Time ◽  
Acid Anhydrides ◽  
Work Up ◽  
Trichloroisocyanuric Acid

AbstractAn efficient mixed reagent for direct synthesis of symmetrical carboxylic anhydrides from carboxylic acids has been prepared. Carboxylic acids are converted to anhydrides using triphenylphosphine/ trichloroisocyanuric acid under mild reaction conditions at room temperature. Short reaction time, excellent yields of products, low cost, availability of reagents, simple experimental procedure, and easy work-up of the products are the main advantages of the presented method.

Regioselective 6-endo-dig iodocyclization: an accessible approach for iodo-benzo[a]phenazines

2017 ◽  
Vol 15 (21) ◽  
pp. 4686-4696 ◽  
Author(s):  
Sonu Kumar ◽  
Mohammad Mujahid ◽  
Akhilesh K. Verma
Keyword(s):  
Molecular Iodine ◽  
Reaction Conditions

A tandem approach for the synthesis of iodo benzo[a]phenazine derivatives using molecular iodine has been described under mild reaction conditions.

Sign in / Sign up

Export Citation Format

Share Document