A RAPID AND FACILE CONVERSION OF PRIMARY AMIDES AND ALDOXIMES TO NITRILES AND KETOXIMES TO AMIDES WITH TRIPHENYLPHOSPHINE AND N-CHLOROSUCCINIMIDE

ABSTRACT

Primary amides and aldoximes are easily converted to their corresponding nitriles using a mixture of triphenylphosphine and N-chlorosuccinimide in dichloromethane at room temperature. The reaction of aldoximes occurs almost immediately and primary amides in 0.5?h by this method. By this procedure secondary amides are produced by Beckmann rearrangement of ketoximes.     

Efficient Beckmann rearrangement and dehydration of oximes via phosphonate intermediates

Under mild conditions, conversion of a variety of ketoximes and aldoximes to their corresponding amides and nitriles proceeded in the presence of diethyl chlorophosphate with excellent yields.     

PEG-SO_3H as catalyst for the Beckmann rearrangement and dehydration of oximes

Under mild conditions, conversion of a variety of ketoximes and aldoximes to their corresponding amides and nitriles proceeded in the presence of PEG-SO3H with high yields.     

Ultrasound-promoted synthesis of nitriles from aldoximes under ambient conditions

Copper(II) acetate proves to be an active catalyst for ultrasound-promoted conversion of aldoximes into nitriles. This dehydration reaction was carried out in acetonitrile under ambient conditions to provide nitriles with moderate tolerance toward water, which allows one-pot synthesis of a nitrile from an aldehyde with minimal purification.     

An Efficient Method for the Preparation of Nitriles via the Dehydration of Aldoximes with Phthalic Anhydride

A new and highly efficient method for the conversion of aldoximes to nitriles was established. By fusing with phthalic anhydride, aldoximes were efficiently and smoothly converted into nitriles, in high yields (over 85%) and in a short time (within 5 minutes). The mixture of phthalic anhydride, a cyclic anhydride, and aldoximes in fusing state set up an ideal transition state for a selective [3.3]‐sigmatropic rearrangement of the acylated aldoximes to nitriles.     

Rapid Method of Converting Primary Amides to Nitriles and Nitriles to Primary Amides by ZnCl2 using Microwaves under Different Reaction Conditions

A rapid and facile method for the conversion of primary amides to nitriles using inexpensive and readily available ZnCl₂ in aqueous acetonitrile and their regeneration using ZnCl₂–H₂O–THF in the presence of acetamide under microwave irradiation in good yields is reported. The reactions go to completion within a minute.     

Ac2O/K2CO3/DMSO: an efficient and practical reagent system for the synthesis of nitriles from aldoximes

The transformation of aldoximes to nitriles using acetic anhydride as dehydration agent under mild reaction conditions is reported. The reaction, which proceeds under weak alkaline condition, allows for the conversion of a range of aldoximes including aromatic aldoximes, alphatic aldoximes, and heterocyclic aldoximes in good to excellent yields. This method has also been successfully applied to the synthesis of calcium channel blocker nilvadipine in pilot scale.     

Simple and Highly Efficient Procedure for Conversion of Aldoximes to Nitriles Using N-(p-Toluenesulfonyl) Imidazole

A facile and efficient method for dehydration of aldoximes into nitriles using N-(p-toluenesulfonyl) imidazole (TsIm) is described. In this method, aldoximes were refluxed with TsIm in the presence of 1,8-diazabicyclo-[5.4.0]undec-7-ene (DBU) in dimethylformamide (DMF) to afford the corresponding nitriles in good yields. This methodology is highly efficient for various structurally diverse aldoximes including aromatic, heteroaromatic, and aliphatic oximes. A plausible mechanism for the conversion of aldoxime into nitriles using TsIm/DBU is explained.     

Phosphonium salt-catalysed synthesis of nitriles from in situ activated oximes

A metal-free catalytic method for the conversion of aromatic and aliphatic aldoximes to nitriles at room temperature using oxalyl chloride (1.2 equiv) in combination with 5 mol % of triphenylphosphine oxide is reported. Of the many potential pathways leading from oxime to nitrile a manifold involving chlorophosphonium salt-catalysed decomposition of oxime chlorooxalates formed in situ is shown to be operative.     

Novel isocyanide-based three-component one-pot synthesis of cyanophenylamino-acetamide derivatives

A one-pot multicomponent synthesis of a novel class of cyanophenylamino-acetamides through the conversion of primary amides to the corresponding nitriles, starting from simple and readily available inputs including 2-aminobenzamide, an aldehyde, and an isocyanide in the presence of p-toluenesulfonic acid as a catalyst, in excellent yields at room temperature in ethanol as a green reaction medium is described.     

Mild and reversible dehydration of primary amides with PdCl2 in aqueous acetonitrile

[reaction: see text] A new, mild, and reversible method to convert primary amides to nitriles in good yields using PdCl2 in aqueous acetonitrile is described.     

FeCl3-silica: A green approach for the synthesis of nitriles from oximes

A green and suitable protocol for the conversion of aldoximes into nitriles is described. The transformation is carried out under solvent-free conditions using FeCl₃-silica medium. The protocol offers a green, single-step facile procedure with the use of less toxic metal salt to isolate nitriles in good to excellent yields.     

SOCl2/β-Cyclodextrin: A New and Efficient Catalytic System for Beckmann Rearrangement and Dehydration of Aldoximes Under Aqueous Condition

A rapid and efficient synthesis of amides via Beckmann rearrangement of ketoximes and dehydration of aldoximes to corresponding nitriles with good to excellent yields has been carried out in the presence of SOCl₂/β-cyclodextrin under aqueous conditions. The β-cyclodextrin has been recovered and reused.     

Envirocat EPZG,R a New Catalyst for the Conversion of Aldoximes Into Nitriles

The conversion of aldoximes into nitriles was carried out at 100°C in the absence of a solvent using Envirocat EPZG^R as a new solid supported catalyst.     

Dehydration of Oximes to Nitriles Catalyzed by a Green Heteropolyacid Catalyst: Preyssler’s Anion, [NaP5W30O110]14－

A mild, simple and high yielding procedure for the direct conversion of oximes to nitriles has been developed using heteropolyacid in acetic acid. Aromatic and aliphatic aldoximes were converted to the corresponding nitriles in the presence of Preyssler type heteropolyacid, which could be reused several times without any appreciable loss of activity.     

Acetohydroxamic acid: a new reagent for efficient synthesis of nitriles directly from aldehydes using Bi(OTf)3 as the catalyst

An efficient method for the preparation of nitriles directly from aldehydes by reaction with AHA using Bi(OTf)₃ as the catalyst is described. Bi(OTf)₃ is shown to be an efficient catalyst also for the conversion of aldoximes into nitriles.     

TrocCl Mediated Efficient Synthesis of Nitriles from Primary Amides

In order to establish a rapid conversion method of primary amides to nitriles, various types of carboxamides were treated with 2,2,2-trichloroethyl chloroformate and Et₃N, as a dehydrating agent to obtain the desired nitriles in 82–95% yields.     

A convenient new procedure for converting primary amides into nitriles

An operationally simple and high-yielding procedure has been developed for the conversion of primary amides to the corresponding nitriles, using ethyl dichlorophosphate/DBU as the mild dehydrating agent.     

MICROWAVE-ASSISTED RAPID DEHYDRATION OF ALDOXIMES TO NITRILES ON A SOLID SUPPORT

p-toluenesulfonyl chloride has been proved out to be an efficient reagent for conversion of aldoximes to the corresponding nitriles under microwave irradiation. Extending the procedure to ketoximes, a 20–40% yield of Beckmann rearranged product was obtained.     

Highly efficient Beckmann rearrangement and dehydration of oximes

Under mild conditions, Beckmann rearrangement of a variety of ketoximes could proceed in the presence of chlorosulfonic acid using toluene as a solvent with excellent conversion and selectivity. This procedure could also be applied in the dehydration of aldoximes for obtaining the corresponding nitriles.