1575-95-7

A new and convenient method was found for the one-pot synthesis of symmetrical and unsymmetrical linear imides by reaction of aliphatic and aromatic nitriles with acyclic carboxylic anhydrides in the presence of silica sulfuric acid as an active and recyclable reagent. Georg Thieme Verlag Stuttgart.

N-Acyl amino acids can be converted by oxidative decarboxylation induced by Ag+/Cu2+/S2O82- at room temperature in water into imides in 24-89% yields. Both N-benzoylvaline and N-benzoylleucine gave N-

The photochemistry of selected N-silylalkyl-substituted phthalimides and maleimides has been investigated with the aim of exploring the generality and preparative consequences of an intriguing solvent effect on excited-state reaction chemoselectivities and quantum efficiencies. An example of this effect is found in the photochemistry of N- [(trimethylsilyl)butyl]phthalimide 10, where irradiation in MeCN leads to production of a mixture of four products that arise by excited-state intramolecular hydrogen-atom abstraction. In contrast, the benzoindolizidine 15 is the sole product produced by a single electron transfer (SET)- desilylation pathway upon irradiation of 10 in 35% H2O-MeCN. Another example of this solvent effect is found in the photochemistry of the N-silylpropyl- maleimide 17. Irradiation in MeCN results in the production of the 2+2-dimer 19 whereas the pyrrolizidine 18 is generated exclusively by irradiation of 17 in 35% H2O-MeCN. The results of fluorescence and triplet sensitization experiments suggest that the solvent effect has multiple sources including the control of the nature, reactivity, and intrinsic lifetimes of singlet and triplet excited states of the phthalimide and maleimide systems. The exploratory studies have clearly demonstrated the generality of this solvent effect and how it can be used to enhance the preparative utility of the photochemistry of N-(silylalkyl)phthalimides and N-(silylalkyl)maleimides.

New N-silver(I) acetylbenzamide complexes of type Ln· AgNC9H8O2 (L = PPh3; n = 1, 2a; n = 2, 2b; n = 3, 2c; L = P(OEt)3; n = 1, 2d; n = 2, 2e; n = 3, 2f) were prepared. These complexes were

The invention discloses a method for preparing derivatives of benzamide under a microwave condition in an aqueous phase. A coupling reaction is carried out between substituted benzoic acid and amine under the microwave condition in the aqueous phase. The method for preparing the derivatives of benzamide is environmentally friendly, easy and convenient to operate, safe, low in cost and efficient. Compared with the prior art, the method can be applicable to a large number of functional groups, is high in yield, produces fewer by-products, and further is easy to operate, safe, low in cost and environmentally friendly. A formula is shown in the description.

The invention discloses a methodfor catalytically oxidizing amine to be synthesized into amide througha dipyridyl-type manganese catalyst. According to the method, a dipyridyl manganese complex formedafter coordination of a dipyridyl-type complex and cheap metal manganese serves as the catalyst, clean and environment-friendly hydrogen peroxide serves as an oxidizing agent, oxidation of N ortho-position sp3 C-H bonds catalyzed by the cheap metal manganese is achieved, and the amine is directly oxidized to obtain the amide. Compared with existing methods, the method has the advantages that theadopted catalyst is low in price, the preparing method is simple, raw materials are easy to obtain, the use level of the catalyst is low, the substrate range is wide, the reaction condition is mild, the operation is simple and environmentally friendly, the reaction time is short, the yield is high, the selectivity is high, and the industrialization cost is low.

A highly selective synthesis of acyl isoureas and imides from readily accessible amides, isocyanides, alcohols and carboxylates based on reaction solvent selection is described. In the presence of a catalytic amount of [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) and cupric acetate, treatment of amides and isocyanides in alcohols at 60 °C provided acyl isoureas in high yields. Interestingly, when other solvents such as acetonitrile was used instead of alcohols, imides were exclusively produced in good to excellent yields via direct N-acylation of amides with carboxylates as the acyl sources. This protocol offers an attractive alternative approach toward isoureas and imides. (Figure presented.).

Imides are prepared conveniently by visible-light-driven oxidations of various N -alkylamides under mild conditions. The majority of the reactions proceed efficiently by using Oxone as the oxidant in the presence of a catalytic amount of KBr in H 2 O/CH 2 Cl 2 under irradiation by an 8 W white LED at room temperature. Experimental studies suggest that an imine, obtained from the substrate amide via a radical process, is the key intermediate.

The invention belongs to the technical field of synthesis of amides, discloses a process for the carbonylation of carbon monoxide in the method of preparing amide, the method is to cheap and easy to obtain the halogenated aromatic hydrocarbon and organic amine compounds as the substrate of reaction, to carbon monoxide as carbonyl source, under light-struck, halogenated aromatic hydrocarbons are cracked to produce free radical, by free-radical addition process to obtain the amide compound. Compared with the traditional carbonylation reaction, the carbon monoxide pressure is extremely low, can react to the atmospheric pressure. This process does not need to rely on any metal catalyst of the booster, mild reaction conditions, environmental protection, with a shorter synthetic route and high utilization efficiency of the atoms, the reaction system with higher substrate tolerance, green sustainable light source as the driving force, the atom economy is high, application prospect.

Aryl carbonyl compounds including acetophenones, benzophenones, imides, and benzoic acids are prepared from benzyl substrates using potassium persulfate as oxidant with catalytic pyridine in acetonitrile under mild conditions. Neither transition metals nor halogens are involved in the reactions.

An oxidative cleavage of C-C double bonds of enamides promoted by hypervalent iodine(III)/TMSN 3 under an air atmosphere is developed. This reaction provides a new approach to construct various cyanobenzamides, which offers further synthetic potential for the preparation of industrial and pharmaceutical nitrogen- and oxygen-containing molecules, and exhibits good functional group tolerance, broad substrate scope and mild conditions.

A novel vanadium-catalyzed one-pot domino reaction of 1,2-diketones with amidines has been identified that enables their transformation into imides and amides. The reaction proceeds by dual acylation of amidines via oxidative C(CO)-C(CO) bond cleavage of 1,2-diketones to afford N,N′-diaroyl-N-arylbenzamidine intermediates. In the reaction, these intermediates are easily hydrolyzed into imides and amides through vanadium catalysis. This method provides a practical, simple, and mild synthetic approach to access a variety of imides as well as amides in high yields. Moreover, one-step construction of imide and amide bonds with a long-chain alkyl group is an attractive feature of this protocol.

Herein we report the highly efficient, environmentally friendly alumina-promoted synthesis of N-aryl-1,2,4-triazoles with a wide variety of substitution patterns from commercially available hydrazines with symmetrical and unsymmetrical imides. Aromatic hydrazines with a variety of substitution patterns provided the corresponding 1,2,4-triazoles in very high yields. Unsymmetrical imides with a wide variety of functional groups also provide the respective triazoles with high yield and complete regioselectivities. The high productivity and mild conditions allow for the large-scale preparation of 1,2,4-triazoles.

A One-Pot tandem Schmidt–Ritter process for the synthesis of amides has been developed using the super acid as catalyst. The in situ generated aryl/aliphatic nitriles from the reaction of aldehydes and sodium azide in the presence of TfOH and AcOH (Schmidt reaction) react with suitable alcohol (Ritter reaction) to give the amides. For the first time we observed that during the Schmidt process N-acylimides were generated along with nitriles, interestingly these N-acylimides also participated in the Ritter reaction.

A new protocol for the synthesis of imides has been developed. In the presence of copper catalyst, N-benzylamides were oxidized to the corresponding imides by TBHP/TEMPO system in moderate to good yields. Imides were synthesized through the oxidation of N-benzylamides by TBHP/TEMPO system in moderate to good yields.

In this Letter, we report the aerobic photo-oxidative synthesis of diacylamines from benzylamides in the presence of molecular oxygen and catalytic amounts of 2-chloroanthraquinones under visible light irradiation from a fluorescent lamp.

A novel and efficient palladium-catalyzed aminocarbonylation of aryl iodides with amides and N-alkyl anilines has been developed. The reaction tolerates a wide range of functional groups and is a reliable method for the rapid synthesis of a variety of valuable imides and tertiary benzanilides under an atmospheric pressure of CO. Copyright

Bis(iodozincio)methane [CH2(ZnI)2] transforms isocyanates (R-N=C=O) into the enolate equivalent of amides via zinciomethylation. The reactivity of the enolate equivalent as a nucleophile toward aldehydes depends on the R group of the

A continuous-flow protocol for the preparation of organic nitriles from carboxylic acids has been developed. The method is based on the acid-nitrile exchange reaction with acetonitrile, used as the solvent, and takes place without any catalyst or additives under the high-temperature/high-pressure conditions employed. At 350 C and 65 bar, where acetonitrile is in its supercritical state, the transformation of benzoic acid to benzonitrile requires 25 min. The protocol has been tested for a variety of nitriles, including aromatic and aliphatic substrates.

A rapid and convenient preparation of acyclic imides by the reaction of aliphatic and aromatic nitriles with acyclic carboxylic anhydride in the presence of catalytic amounts of p-toluenesulfonic acid under thermal or ultrasonic conditions is reported. The advantages of this procedure are moderate reaction times, good to excellent yields, and use of an inexpensive and ecofriendly catalyst. The reaction of nitriles with aliphatic anhydrides proceeds under thermal conditions, while they are accelerated by the use of ultrasound irradiation.

A combination of F-TEDA-PF6 and CuBr (0.1 equiv.) provides a potent oxidant that readily oxidizes amides to provide imides at room temperature. Replacement of BF4-, the anion of Selectfluor (F-TEDA-BF4), by PF6-, dramatically reduces CuBr loading in this oxidative reaction. A possible rationale for this dramatic counterion effect is provided.

Facile and efficient procedures for the N-acylation reaction of amide derivatives with various acid anhydrides and the cyclization reaction of N-acylated amide derivatives with various hydrazine hydrochlorides were described. The reactions were carried out under microwave irradiation to give products in good yields in a few minutes. The synthesis of 1,3,5-trisubstituted- 1,2,4-triazoles from benzamides can also be accomplished in a simple one-pot sequential reaction.

The extraction behaviour of UVI from an aqueous nitrate medium employing N-acetyl benzamide in chloroform has been investigated in presence of several donors like trioctyl phosphine oxide, pyridine and dimethyl sulphoxide. The metal was assayed by UV-Vis spectrophotometry method. The overall equilibrium constant for each of the three ternary extraction systems were estimated and role of different thermodynamic parameters are discussed.

We have developed a new method for the preparation of unsymmetrical imides using liquid carboxylate salts via a Ritter-type process. The reactions were carried out with nitriles and n-butylammonium carboxylates as ionic liquids in the presence of triflic anhydride (Tf2O) as the promoter. Mild reaction conditions, simplicity of the procedure, and proton-free conditions are the main advantages of this procedure.

An efficient and environmentally friendly procedure has been developed for the synthesis of symmetrical and unsymmetrical acyclic imides by the reaction of nitriles with acyclic anhydrides in the presence of catalytic amounts of 12-tungstophosphoric acid (H3PW12O40) under thermal conditions and microwave irradiation. It was found that microwave improves the yields and significantly reduces the reaction times. Furthermore, the catalyst could be recovered and reused several times without decrease in its activity.

The combination of Selectfluor and copper(I) bromide has shown a strong oxidation ability, readily oxidizing amides into the corresponding imides in acetonitrile at room temperature in less than 1 h. This transformation under mild conditions gives good to excellent chemical yields. A possible reaction mechanism is proposed.

Commercially available and preparative ZnO nanoparticles are reported as efficient and reusable catalysts for the chemoselective synthesis of N-acylsulfonamides and sulfonate esters. A one-pot sequential sulfonylation and acylation of amines took place to afford the N-acylsulfonamides in excellent yields under solvent-free conditions. The ZnO catalyst can be reused for without significant loss of catalytic activity.

Benzylamides were found to be oxidized to their corresponding diacylamines in the presence of molecular oxygen, catalytic 48% aq HBr, and Ca(OH) 2 under visible light irradiation of a fluorescent lamp.

Oxidation of α-amidoaryl sulfones with m-chloroperoxybenzoic acid under mild conditions readily provides the corresponding imides in satisfactory yields. The overall processprobably involves formation of an N-acyliminium ion intermediate, which by attack

The BF3·Et2O-induced decomposition of ethyl 2-diazo-3-hydroxy-3,3-diarylpropanoates, prepared by the addition of a series of benzophenones to ethyl diazo(lithio)acetate, is reported and studied. By using acetonitrile as a solvent, the corresponding N-acyl β-enamino ester derivatives are obtained in good yields and with a diverse regioselectivity as the result of 1,2-aryl migration in the vinyl cation intermediates. The factors that govern the migratory aptitude as well as the mechanistic aspects of the reaction are discussed.

We have developed a general and highly efficient iron(II) chloride/N-bromosuccinimide (NBS)-mediated method for the synthesis of imides and acylsulfonamides via couplings of thioesters with carboxamides/sulfonamides, and the method is simple, economical and shows practical advantages.

We have developed a highly efficient method for the copper-catalyzed amidation of aldehydes in the presence of N-bromosuccinimide (NBS). This method is simple, economical, and has practical advantages for synthesis of imides.

Benzylamides were found to be oxidized to the corresponding imides in the presence of molecular oxygen and catalytic iodine under photoirradiation. Georg Thieme Verlag Stuttgart.

The photochemistry of some 3,5-disubstituted 1,2,4-oxadiazoles in the presence of 2,3-dimethyl-2-butene has been investigated. The irradiation in acetonitrile yielded differently substituted N-imidoyl-aziridines through an aziridination reaction involving an acyliminonitrene intermediate. Pyrolysis of N-imidoyl-aziridines produced the corresponding N-allylamidines through a ring opening process.

The ceric ammonium nitrate promoted oxidations of 4,5-diphenyloxazoles and oxazoles with various substitution patterns have been investigated. This transformation results in the formation of the corresponding imide in good yield and tolerates a wide variety of functional groups and substituents on the oxazole moiety.

FSM-16, a mesoporous silica, was found to catalyze oxidative photo-decarboxylation of α-hydroxy carboxylic acid, phenyl acetic acid derivatives and N-acyl-protected α-amino acids to afford the corresponding carbonyl compounds. Furthermore, FSM-16 proved to be re-usable by re-calcination at 450°C after the reaction.

N-Hydroxyphthalimide (NHPI)-catalyzed aerobic oxidations in the ionic liquids were examined for the first time. Both NHPI and its ionic derivative, 3-pyridinylmethyl-N-hydroxyphthalimide (Py-NHPI), were found to have better performance in the ionic liquid than in the conventional organic solvents for the aerobic oxidation of N-alkylamides to imides. On the other hand, Py-NHPI was found to be a much better catalyst than NHPI for the aerobic oxidation of benzylic compounds in the ionic liquid.

Direct transformation of aliphatic carboxylic acids to the corresponding nitriles can be easily performed with acetonitrile in the presence of sulfuric acid. Georg Thieme Verlag Stuttgart.

A novel and practical procedure for preparation of imides is described using chromium(VI) oxide to catalyze the oxidation of N-alkylamides with periodic acid in the presence of acetic anhydride in acetonitrile.

A mechanism involving the intermediate formation of an amine radical cation by single-electron transfer is proposed for the oxidation of secondary amines with alkylperoxy-λ3-iodane. On the other hand, the oxidation of acetamides probably proceeds by a radical process, which involves the direct hydrogen abstraction of the methylene group α to the nitrogen atom.

The oxidation of N-alkylamides by O2, catalyzed by N-hydroxyphthalimide (NHPI) and Co(II) salt, leads under mild conditions to carbonyl derivatives (aldehydes, ketones, carboxylic acids, imides) whose distribution depends on the nature of the alkyl group and on the reaction conditions. Primary N-benzylamides lead to imides and aromatic aldehydes at room temperature without any appreciable amount of carboxylic acids, while under the same conditions nonbenzylic derivatives give carboxylic acids and imides with no trace of aldehydes, even at very low conversion. These results are explained through hydrogen abstraction by the phthalimide-N-oxyl (PINO) radical, whose reactivity with benzyl derivatives is governed by polar effects, so that benzylamides are much more reactive than the corresponding aldehydes. The enthalpic effect is, however, dominant with nonbenzylic amides, making the corresponding aldehydes much more reactive than the starting amides. The importance of the bond dissociation energy (BDE) of the O-H bond in NHPI is emphasized.

New procedures based on the oxidation by bromine-catalysed hydrogen peroxide in a two-phase system provide simple and cheap transformations of alkylamines to carbonyl derivatives (aldehydes, ketones, carboxylic acid, imides, lactams) through the corresponding acetamides.

FSM-16, a mesoporous silica, was found to promote the oxidative photodearboxylation of N-acyl-protected α-amino acids in hexane to afford the corresponding imides.

tert-Butylperoxyiodane undergoes oxidation of the methylene groups α to the nitrogen atom of amides (or carbamates) yielding imides or tert- butylperoxyamide acetals, depending on the reaction conditions. A proposed mechanism involves generation of carbon-centered radicals α to the nitrogen atom.

A combination of acetic anhydride and chloro-trimethylsilane has been shown to effect the conversion of a variety of azides to the corresponding acetylated amines in excellent yields without affecting other functional groups such as ether, ester, halide etc.

Several symmetrical 2,2′,4,4′-tetrasubslituted[4,4′-bioxazole]-5,5′(4H, 4′H)-diones 1a-f were obtained by dehydrodimerization of 5(4H)-oxazolones 2a-f. The configurations of four were established; one by X-ray crystallography rac-1c, and three rac-1a, meso-1a and rac-1b by 1H nmr spectroscopy of their derivatives. Upon being heated, the bioxazolones isomerized, presumably by breakage of the 4,4′-carbon-carbon bond to form free radicals followed by their recombination. The results of a crossover experiment were consistent with a radical nature for this isomerization reaction. Treatment of three of the bioxazolones rac-1a, mew-1a and rac-1c with methanol and amine nucleophiles led to ester and amide derivatives 7-11 of α,α′-dehydrodimeric amino acids.

Acylamides, acylcarbamates and acylureas have been synthesized by acylation of amides, carbamates and ureas sodium salts with alk-1-en-2-yl esters prepared with 2 as catalyst.

The mixed open-chain imide N-(3-chloro-4-hydroxyphenylacetyl)fumarate (1), named coniothyriomycin, was isolated as a metabolite of the fungus Coniothyrium.The natural product 1 and the analoguos imides 13-15 and 22-24 have been synthesized by base-catalyzed condensation of the imidates 12a-f with acid chlorides 6a-c or the mixed anhydride 21.The compounds 1 and 13-15 were shown to posess remarkable fungicidal and herbicidal activities in short-termed tests. Key Words: Fungal metabolites / Imides, open-chain / Fungicidal activity / Coniothriomycin

The rates of gas-phase elimination of N-t-butylbenzamide 1, N-acetylbenzamide 2, and N-acetyl-N-methylacetamide have been measured in the ranges 674-734, 580-620 and 696-765 K, respectively.The compounds undergo unimolecular first order elimination reactions for which log A = 11.1, 13.7 and 10.5 s-1 and Ea = 172.6, 171.7 and 167 kJ mol-1, respectively.At 600 K, the following reactivity ratios are observed: 1 : N-t-butylacetamide 3, 260; t-butyl benzoate 4 : t-butylacetate 5, 2.3; N-acetylacetamide 6 : N-acetyl-N-methylacetamide, 290; and 2 : 6, 3.6.These relative rate factors show that the phenyl group increases the rate of thermolysis due to its electron-withdrawing ability 250 times more for simple amides than for esters and diamides.These relative rate differences are highly affected by the nature of the Cα-X bond.The pronounced effect of the phenyl group on simple amides could be explained in terms of the low polarity of the Cα-NH bond relative to the more polar Cα-O bond in esters.On the other hand the pronounced deactivation effect of the methyl group in N-acetyl-N-methylacetamide is highly reflected in the reactivity ratio of 290 between 6 and N-acetyl-N-methylacetamide which could be explained in terms of the greater bond order of the Cα-X bond in the latter than in the former.Furthermore, the small reactivity ratio in the diamides 2 and 6 is consistent with the fact that resonance between the lone-pair of electrons on X and the α-carbonyl group increases the Cα-X bond order, thus rendering the Cα-X bond breakage more difficult.We have also measured the rates of thermolysis of N-ethylthioacetamide and N-prop-2-ylthioacetamide.The relative primary : secondary : tertiary rates at 600 K of 1 : 1.3 : 1.5 for the thioamides suggests that the transition state for this class of compound is much less polar than that for the thioacetates.

Amides, thioamides, ureas, and thioureas were N-acetylated in good yield with acetic acid in the presence of methyl bis(1-naphthyl)bismuthinate at room tempereature.