Preparation Of Ketones From Nitriles

Nitrile

This article is about the group of organic compounds. For the synthetic rubber product, see Nitrile rubber. The structure of a nitrile: the functional group is highlighted blue. A nitrile is any organic compound that has a −C≡N functional group.[1] The prefix cyano- is used interchangeably with the term nitrile in industrial literature. Nitriles are found in many useful compounds, including methyl cyanoacrylate, used in super glue, and nitrile rubber, a nitrile-containing polymer used in latex-free laboratory and medical gloves. Nitrile rubber is also widely used as automotive and other seals since it is resistant to fuels and oils. Organic compounds containing multiple nitrile groups are known as cyanocarbons. Inorganic compounds containing the −C≡N group are not called nitriles, but cyanides instead.[2] Though both nitriles and cyanides can be derived from cyanide salts, most nitriles are not nearly as toxic. Structure and basic properties[edit] The N−C−C geometry is linear in nitriles, reflecting the sp hybridization of the triply bonded carbon. The C−N distance is short at 1.16 Å, consistent with a triple bond.[3] Nitriles are polar, as indicated by high dipole moments. As liquids, they have high dielectric constants, often in the 30s. History[edit] The first compound of the homolog row of nitriles, the nitrile of formic acid, hydrogen cyanide was first synthesized by C. W. Scheele in 1782.[4][5] In 1811 J. L. Gay-Lussac was able to prepare the very toxic and volatile pure acid.[6] The nitrile of benzoic acids was first prepared by Friedrich Wöhler and Justus von Liebig, but due to minimal yield of the synthesis neither physical nor chemical properties were determined nor a structure suggested. Théophile-Jules Pelouze synthesized propionitrile in 18 Continue reading >>

Preparation Of Ketones From Nitriles And Phosphoranes

Abstract The preparation of a ketone from a phosphorane and a nitrile is described. The workup conditions are mild, and the yields are high. The unreacted starting materials can easily be recovered. Continue reading >>

Organic Chemistry/ketones And Aldehydes

Aldehydes () and ketones () are both carbonyl compounds. They are organic compounds in which the carbonyl carbon is connected to C or H atoms on either side. An aldehyde has one or both vacancies of the carbonyl carbon satisfied by a H atom, while a ketone has both its vacancies satisfied by carbon. 3 Preparing Aldehydes and Ketones Ketones are named by replacing the -e in the alkane name with -one. The carbon chain is numbered so that the ketone carbon, called the carbonyl group, gets the lowest number. For example, would be named 2-butanone because the root structure is butane and the ketone group is on the number two carbon. Alternatively, functional class nomenclature of ketones is also recognized by IUPAC, which is done by naming the substituents attached to the carbonyl group in alphabetical order, ending with the word ketone. The above example of 2-butanone can also be named ethyl methyl ketone using this method. If two ketone groups are on the same structure, the ending -dione would be added to the alkane name, such as heptane-2,5-dione. Aldehydes replace the -e ending of an alkane with -al for an aldehyde. Since an aldehyde is always at the carbon that is numbered one, a number designation is not needed. For example, the aldehyde of pentane would simply be pentanal. The -CH=O group of aldehydes is known as a formyl group. When a formyl group is attached to a ring, the ring name is followed by the suffix "carbaldehyde". For example, a hexane ring with a formyl group is named cyclohexanecarbaldehyde. Aldehyde and ketone polarity is characterized by the high dipole moments of their carbonyl group, which makes them rather polar molecules. They are more polar than alkenes and ethers, though because they lack hydrogen, they cannot participate in hydrogen bonding like Continue reading >>

Preparation Of Nitriles From Cyanogen And Ketones

Unite States Patent PREPARATION OF NITRILES FROM CYANOGEN AND KETONES William L. Fierce, Crystal Lake, and Walter J. Sandner, Carpentersville, Ill., assignors to The Pure Oil Company, Chicago, 111., a corporation of Ohio No Drawing. Application May 14, 1957 Serial No. 658,976 15 Claims. (Cl. 260-465) This invention relates to new and useful improvements in methods for preparing organic nitriles and more particularly to a method of preparing aliphatic and aromatic nitriles by reaction of cyanogen and ketones at elevated temperatures. It is, therefore, one object of this invention to provide an improved method for preparing aliphatic and aromatic nitriles. Another object of this invention is to provide a method of preparing a variety of aliphatic and aromatic nitriles from ketones. A feature of this invention is the provision of a process for preparing aliphatic and aromatic nitriles by the high temperature reaction of cyanogen and a ketone. Another feature of this invention is the provision of a process for preparing aliphatic and aromatic nitriles, such as acetonitrile, propionitrile, acrylonitrile, and benzonitrile by the high temperature reaction of cyanogen and lower alkyl and aryl ketones at a temperature above the decomposition point of the ketone. Other objects and features of this invention will become apparent from time to time throughout the specification and claims as hereinafter related. This invention comprises a process in which a ketone and cyanogen are reacted at a temperature in the range from 500 to 1000 C. Within this range of temperature aliphatic and aromatic ketones decompose readily to produce free radicals and carbon monoxide, with the free radicals reacting rapidly with cyanogen to produce aliphatic and aromatic nitriles as the principal reaction

Chapter 20: Carboxylic Acid Derivatives. Nucleophilic Acyl Substitution

Summary | Reactions of Acyl Halides | Reactions of Acid Anhydrides | Reactions of Esters | Reactions of Amides | Reactions of Nitriles | Reactions of Nitriles Chapter 20: Carboxylic Acid Derivatives. Nucleophilic Acyl Substitution Reaction type: Nucleophilic Addition Overview Nitriles typically undergo nucleophilic addition to give products that often undergo a further reaction. The chemistry of the nitrile functional group, CºN, is very similar to that of the carbonyl, C=O of aldehydes and ketones. Compare the two schemes: versus However, it is convenient to describe nitriles as carboxylic acid derivatives because: the oxidation state of the C is the same as that of the carboxylic acid derivatives. hydrolysis produces the carboxylic acid Like the carbonyl containing compounds, nitriles react with nucleophiles via two scenarios: Strong nucleophiles (anionic) add directly to the CºN to form an intermediate imine salt that protonates (and often reacts further) on work-up with dilute acid. Examples of such nucleophilic systems are : RMgX, RLi, RCºCM, LiAlH4 Weaker nucleophiles (neutral) require that the CºN be activated prior to attack of the Nu. This can be done using a acid catalyst which protonates on the Lewis basic N and makes the system more electrophilic. Examples of such nucleophilic systems are : H2O, ROH The protonation of a nitrile gives a structure that can be redrawn in another resonance form that reveals the electrophilic character of the C since it is a carbocation. Hydrolysis of Nitriles Reaction type: Nucleophilic Addition then Nucleophilic Acyl Substitution Summary Nitriles, RCºN, can be hydrolyzed to carboxylic acids, RCO2H via the amide, RCONH2. Reagents : Strong acid (e.g. H2SO4) or strong base (e.g. NaOH) / heat. Related Reactions MECHANISM OF TH Continue reading >>

Insertions Of Ketones And Nitriles Into Organorhodium(i) Complexes And B-hydrocarbyl Eliminations From Rhodium(i) Alkoxo And Iminyl Complexes.

Organometallics 2008, 27, 4749-4757. A series of tris(triethylphosphine)-ligated organorhodium(I) complexes were prepared, and their reactions with electron-poor arylnitriles and diarylketones were studied. [(PEt3)3Rh(Ar)] (Ar = phenyl (1a) or o-anisyl (1e)) reacted with an excess of electron-poor arylnitriles Ar′C≡N (Ar′ = p-CF3C6H4 or 3,5-bis(CF3)C6H3) to form Rh(I) iminyl complexes {(PEt3)3Rh[N═C(Ar)(Ar′)]} (2h−j). In contrast, 3,5-bis(CF3)C6H3CN did not insert into the M−C bond of the arylrhodium(I) complexes [(PEt3)3Rh(Ar)] (Ar = p-CF3C6H4 (1f) or 3,5-bis(CF3)C6H3 (1g)), containing more electron-poor aryl groups. The kinetic data for nitrile insertions were most consistent with a pathway involving initial ligand dissociation, followed by a classic migratory insertion. The iminyl complexes 2i−j decomposed at higher temperatures via β-aryl eliminations with selective migration of the more electron-poor aryl group 3,5-bis(CF3)C6H3 to form 1g and the corresponding nitriles. Migratory aptitudes of various aryl groups were assessed by studying β-aryl eliminations from a variety of iminyl complexes. Kinetic data for these β-aryl eliminations were most consistent with initial phosphine dissociation and carbon−carbon bond cleavage of the resulting 14-electron intermediate. Insertions of diarylketones Ar(Ar′)C═O (Ar = 3,5-bis(CF3)C6H3, Ar′ = Ph or 3,5-bis(CF3)C6H3)) into 1a also occurred, although the resulting Rh(I) alkoxides {(PEt3)2Rh[OC(Ph)(Ar)(Ar′)]} (3f−g) were not stable under the reaction conditions and could not be directly identified. Instead, a mixture of {(PEt3)3Rh[3,5-bis(CF3)C6H3]} (1g) and the ketone Ph(Ar′)C═O (Ar′ = Ph or 3,5-bis(CF3)C6H3)) were detected as the major products, indicating that decomposition of alkoxides 3f Continue reading >>

Grignard Reaction Grignard Reagents

The Grignard Reaction is the addition of an organomagnesium halide (Grignard reagent) to a ketone or aldehyde, to form a tertiary or secondary alcohol, respectively. The reaction with formaldehyde leads to a primary alcohol. Grignard Reagents are also used in the following important reactions: The addition of an excess of a Grignard reagent to an ester or lactone gives a tertiary alcohol in which two alkyl groups are the same, and the addition of a Grignard reagent to a nitrile produces an unsymmetrical ketone via a metalloimine intermediate. (Some more reactions are depicted below) Mechanism of the Grignard Reaction While the reaction is generally thought to proceed through a nucleophilic addition mechanism, sterically hindered substrates may react according to an SET (single electron transfer) mechanism: The Grignard reagent can act as base, with deprotonation yielding an enolate intermediate. After work up, the starting ketone is recovered. A reduction can also take place, in which a hydride is delivered from the β-carbon of the Grignard reagent to the carbonyl carbon via a cyclic six-membered transition state. With carboxylic acid chlorides: Esters are less reactive than the intermediate ketones, therefore the reaction is only suitable for synthesis of tertiary alcohols using an excess of Grignard Reagent: With nitriles: With CO2 (by adding dry ice to the reaction mixture): With oxiranes: Recent Literature Highly Enantioselective Desymmetrization of Anhydrides by Carbon Nucleophiles: Reaction of Grignard Reagents in the Presence of (-)-Sparteine R. Shintani, G. C. Fu, Angew. Chem. Int. Ed., 2002, 41, 1057-1059. Added-Metal-Free Catalytic Nucleophilic Addition of Grignard Reagents to Ketones H. Zong, H. Huang, J. Liu, G. Bian, L. Song, J. Org. Chem., 2012, 77, 4645- Continue reading >>

Reactions Of Rli Or Rmgx With Nitriles

Step 1: The nucleophilic C in the organometallic reagent adds to theelectrophilic C in the polar nitrile group. Electrons from the C≡N move to the electronegative N creating an intermediate imine salt complex. Step 2: An acid/base reaction. On addition of aqueous acid, the intermediate salt protonates giving the imine. Step 3: An acid/base reaction. Imines undergo nucleophilic addition, but require activation by protonation (i.e. acid catalysis). Step 4: Now the nucleophilic O of a water molecule attacks the electrophilicCwith the π bond breaking to neutralise the change on the N. Step 5: An acid/base reaction. Deprotonate the O from the water molecule to neutralise the positive charge. Step 6: An acid/base reaction. Before the N system leaves, it needs to be made into a better leaving group by protonation. Step 7: Use the electrons on the O in order to push out the N leaving group, a neutral molecule of ammonia. Step 8: An acid/base reaction. Deprotonation reveals the carbonyl group ofthe ketone product. IR - presence of high frequency C=O, C-Cl too low to be useful 1H NMR - only the protons adjacent to the C=O are particularly characteristic. 13C NMR C=O typically 160-180 ppm (deshielding due to O) minimal intensity, characteristic of C's with no attached H's UV-VIS two absorption maxima π→ π* (<200 nm) n→ π* (~235 nm) πelectron from π of C=O n electron from O lone pair π* antibonding C=O Mass Spectrometry Prominent peak corresponds to formation of acyl cations (acylium ions) IR - presence of two, high frequency C=O Absorbance (cm-1) Interpretation 1820 C=O stretch 1750 C=O stretch 1H NMR - only the protons adjacent to the C=O are particularly characteristic. 13C NMR C=O typically 160-180 ppm (deshielding due to O) minimal intensity, characteristic of C's Continue reading >>

Grignard Reactions Of Nitriles In Benzene

by Bombard et al, Tet Lett 21, 155-158 (1980) OCR, graphics and french translation by Rhodium [ Back to the Chemistry Archive ] Compared to the corresponding carbonyl compounds, the nitriles are substrates not very reactive with etheral organomagnesium solutions; they do not readily form the desired ketones, and the reactions oftern give low yields. To increase their reactivity, several authors [1] have used toluene as the reaction solvent, and higher temperatures could be achieved (reflux of the toluene). The increase in the obtained yields was attributed to the higher temperature and not to the reactivity of the organomagnesium species in this solvent [2]. In the present communication, we describe the first results of our performed reasearch of nitriles at ambient temperature, with the Grignard reagent, prepared in benzene in the presence of one equivalent of diethyl ether (table 1). Grignard Nitrile Solvent (1) G/N (2) Yield P2P PhCH2MgCl CH3CN Ether 1.2 20% PhCH2MgCl CH3CN Ether 2.0 29% PhCH2MgCl CH3CN Benzene 1.2 40% PhCH2MgCl CH3CN Benzene 2.0 48% (1) When benzene was used as solvent, the grignard reagent was first prepared in ether, then evaporated and dissolved in benzene. (2) Ratio of Grignard reagent to the nitrile The results in this table show, in fact, that the yields of ketones in the investigated reactions in benzene are superior to 80%, while they do not exceed 50% in diethyl ether at the same temperature. A known exception has be signaled: the acetonitrile with benzylmagnesium chloride furnishes less than 50% of the corresponding ketone [3]. Besides, as It is well known [4] that using an excess quantity of organomagnesium reagent to a nitrile gives primary amines as a side product. The mechanism of the nucleophilic addition of the Grignard reagents to t Continue reading >>

01 Apra Nickel For A Ketone

Direct Synthesis of Arylketones by Nickel-Catalyzed Addition of Arylboronic Acids to Nitriles Ketones from boronic acids and nitriles One of the first contracts we carried out in GalChimia was the preparation of a ketone present as impurity in a process for an API. The synthesis relied in the addition of an organomagnesium compound to a nitrile. The nitrile was commercially available, but the organomagnesium compound had to be prepared from the corresponding bromide, magnesium turnings and iodine or 1,2-dibromethane as promotor. A modern version of this reaction can be seen in this paper by Cheng et al. (National Tsing Hua UniVersity, Taiwan). Their studies follow the trail of other metal mediated protocols for the addition of boronic acids to nitriles, but in this case using a first-row transition metal: Nickel. The use of different bidentante Ni complexes and a Lewis acid allows the succesful addition of different boronic acids to the nitriles. In a typical protocol, a sealed tube containing Ni(dppe)Cl2 (10 mol%), ZnCl2 (150 mol%) and boronic acid (200 mol%) is purged and then the nitrile, H2O (100 mol%) and 1,4-dioxane were sequentially added to the system and the reaction heated at 80 °C for 8 h. Two striking points about the protocol are the introduction of water to enhance the yield, something not expected when using ZnCl2, and the absence of base; no base is necessary for the transmetalation of arylboronic acid to the nickel center. The protocol is efficient and gives good yields. Since the reaction system uses 1,4-dioxane as solvent, microwave heating should not be specially effective here, but the presence of water and the zinc salt could change that, so it is worth giving it a try. No examples of heterocycles are given, so there is room for more work. Org. Le Continue reading >>

Hyperglycemia and Ketone Testing

-unsaturated Esters, Ketones And Nitriles Using Microwave And Solvent-free Conditions

ARTICLE Synthesis of b-phenylchalcogeno-a, b Eder J. LenardãoI, *; Márcio S. SilvaI; Samuel R. MendesI; Francisco de AzambujaI; Raquel G. JacobI; Paulo César Silva dos SantosII; Gelson PerinI, * IInstituto de Química e Geociências, Universidade Federal de Pelotas, CP 354, 96010-900 Pelotas-RS, Brazil IIDepartamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil ABSTRACT A simple, clean and efficient solvent-free protocol was developed for hydrochalcogenation of alkynes containing a Michael acceptor (ester, ketone and nitrile) with phenylchalcogenolate anions generated in situ from the respective diphenyl dichalcogenide (Se, Te, S), using alumina supported sodium borohydride. This efficient and improved method is general and furnishes the respective (Z)-b-phenylchalcogeno-a,b-unsaturated esters, ketones and nitriles, in good yield and higher selectivity, compared with those that use organic solvent and inert atmosphere. The use of microwave (MW) irradiation facilitates the procedure and accelerates the reaction. Keywords: microwave irradiation, solvent-free reaction, b-phenylchalcogeno esters, b-phenylchalcogeno ketones, b-phenylchalcogeno nitriles RESUMO Um método simples e eficiente foi desenvolvido para a hidrocalcogenação de alquinos contendo um aceptor de Michael (éster, cetona e nitrila) com ânions fenilcalcogenolatos gerados in situ a partir do respectivo dicalcogeneto de difenila (Se, Te, S), usando hidreto de boro e sódio suportado em alumina e meio livre de solvente. Este método é geral e permite a obtenção de ésteres, cetonas e nitrilas (Z)-b-fenilcalcogeno-a,b-insaturados, com rendimentos e seletividade comparados aos obtidos quando se utiliza solvente orgânico e atmosfera inerte. O uso de irradiação de m Continue reading >>

Grignard Reagent

This is a wiki on Grignard Reagents, their preparatory steps, and their uses. This wiki is for all-information-Grignard. Grignard reagents are useful compounds in metalorganics that can be used to produce a wide range of alcohols; however they are very difficult to prepare. The typical preparation of Grignards is shown in figure 1: In Figure 1, a Grignard is prepared by reacting a halogenated compound with either lithium or magnesium in ether. can be aliphatic or aromatic and is a halogen like chlorine, bromine, of iodine. Difficulty of Grignard Reagents Grignards are difficult to prepare because they easily react with the common molecules of life, as shown in Figure 2: As shown in Figure 2, Grignards will become when reacted with carbon dioxide, or will become the original compound () used to prepared the Grignard if in the pressence of . Take special care to note the middle path for it details the typical use of a Grignard; the addition of groups (aromatic or aliphatic) to form complex alcohols. Grignards can be reacted with aldehydes or ketones to form or alcohols; respectively. The key is that Grignards love attacking carbonyl groups (). Mechanism of a Grignard Attack on a Carbonyl group Grignards attack carbonyls to form alkoxides. Note that the alkoxide must be protonated to obtain the desired alcohol. Nucleophilic Addition Unto Epoxides Grignards possess the ability to attack epoxide compounds; however, these reagents are selective of which carbon in an epoxide ring they will attack. Take note the the Grignard in the image above attacked the least substituted carbon in the epoxide ring, which opened up the epoxide ring to form a alkoxide. After protonation, the desired alcohol was produced. Attack on Nitriles Grignards further possess the property to form ketones Continue reading >>

A2 Organic Reactions / Reagents & Conditions

1. GRIGNARD REAGENTS Â· Preparation: i. HALOALKANE + Mg â†’ GRIGNARD Â· Reagents and Conditions: 1) Heat under reflux 2) Dry Ether 3) Single Crystal of Iodine catalyst if needed Â· Reactions: i. GRIGNARD + CO2(cold/solid) â†’ (+1C)CARBOXYLIC ACID + MgBrCl (+1C = the addition of one Carbon molecule to the chain) ii. GRIGNARD + METHANAL â†’ (+1C) 1Âº ALCOHOL + MgBrCl iii. GRIGNARD + Other ALDEHYDES â†’ (+1C) 2Âº ALCOHOL +MgBrCl iv. GRIGNARD + KETONE â†’ (+1C)3Âº ALCOHOL + MgBrCl Â· Reagents and Conditions: 1) Dry Reagents 2) With HCl 2. CARBOXYLIC ACIDS Â· Preparation: i. 1Âº ALCOHOLS + 2[O] â†’ CARBOXYLIC ACID + WATER Â· Reagents and Conditions: 1) Heat under Reflux 2) Potassium Dichromate / H2SO4 ii. Hydrolysis of Nitriles NITRILE + 2H2O + HCl â†’ CARBOXYLIC ACID + NH4Cl Â· Reagents and Conditions: 1) Heat under reflux 2) With dilute HCl Â· Reactions: i. CARBOXYLIC ACID + NaOH â†’ CARBOXYLATE SALT + H2O ii. CARBOXYLIC ACID + Na2CO3/NaHCO3 â†’ CARBOXYLATE SALT + H2O + CO2 iii. CARBOXYLIC ACID + ALCOHOL â†” ESTER + H2O Â· Reagents and Conditions: 1) Warmed under reflux 2) With concentrated H2SO4 iv. CARBOXYLIC ACID + PCl5 â†’ ACID CHLORIDE + POCl3 + HCl Â· Reagents and Conditions: 1) Dry / room temperature v. CARBOXYLIC ACID + 4[H] â†’ ALCOHOL + H2O Â· Reagents and Conditions: 1) LiAlH4 in dry ether 2) With HCl 3. ACID CHLORIDES: Â· Preparation: i. CARBOXYLIC ACID + PCl5 â†’ ACID CHLORIDE + HCl + POCl3 Â· Reactions: i. ACID CHLORIDE + H2O â†’ CARBOXYLIC ACID + HCl ii. ACID CHLORIDE + ALCOHOL â†’ ESTER + HCl iii. ACID CHLORIDE + (concentrated)AMMONIA â†’ AMIDE + NH4Cl iv. ACID CHLORIDE + AMINE â†’ SUBSTITUTED AMIDE + HCl 4. ESTERS: Â· Preparation: i. CAR Continue reading >>

An Improved Synthesis Of 5-halopyrimidines: Reaction Of Α-halo Ketones With Nitriles

© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.A. García Martínez* , A. Herrera Fernández, Dolores Molero Vilchez, M. Hanack, L. R. Subramanian Continue reading >>

Efficient And Scalable Synthesis Of Ketones Via Nucleophilic Grignard Addition To Nitriles Using Continuous Flow Chemistry

In the present Letter we report the development of efficient continuous flow chemistry conditions for the scalable preparation of ketones. This transformation is achieved via nucleophilic addition of Grignard reagents to the corresponding nitriles and imine hydrolysis by means of in-series plug flow reactors. Graphical abstract Continue reading >>