Substituted acetonitriles, reaction with

An aromatic nitro group sometimes participates in the formation of indoles, in particular of N-hydroxy derivatives. For example, the reaction of ort/io-nitroaryl substituted acetonitriles 29 with acetaldehyde followed by treatment with K2CO3 afforded N-hydroxyindoles 30, as the major products [38] (Scheme 16). 

Kinetic studies have been carried out on the displacement reactions of various chloroazanaphthalenes with ethoxide ions and piperi-dine. - 2-Chloroquinoxaline is even more reactive than 2-chloro-quinazoline, thus demonstrating the powerfully electrophilic nature of the -carbon atoms in the quinoxaline nucleus. The ease of displacement of a-chlorine in the quinoxaline series is of preparative value thus, 2-alkoxy-, 2-amino-, - 2-raethylamino-, 2-dimethyl-amino-,2-benzylamino-, 2-mercapto-quinoxalines are all readily prepared from 2-chloroquinoxaline. The anions derived from substituted acetonitriles have also been used to displace chloride ion from 2-chloroquinoxaline, ... 

Related and equally important reactions are the acetoacetic ester synthesis and the eyanoaeetie ester synthesis Here too the initial substituted product can be hydrolyzed and decarboxylated, to yield a ketone 11 (i.e. a substituted acetone) from acetoacetic ester 10, and a substituted acetonitrile 14 from eyanoaeetie ester 13 respectively. Furthermore a substituted acetoacetic ester can be cleaved into a substituted acetic ester 12 and acetate by treatment with strong alkali ... 

The Knoevenagel reaction between o-hydroxyaryl aldehydes and ketones and substituted acetonitriles affords high yields of 3-substituted coumarins in aqueous alkaline media <96H(43)1257>, whilst 4-hydroxycoumarins have been elaborated to pyrano [3,2-c]benzopyran-5-ones by reaction with aromatic aldehydes and malononitiile <96P148>. The imine (10) resulting from the complex reaction of o-hydroxyacetophenone with malononitrile undergoes a 1,5-tautomeric shift in solution <96JCS(P1)1067>. 

The same direction of nucleophilic attack was found for quinocyclopropene 116 on reaction with Na-ethanolate and Na-acetonitrile, which gave the salts 485/486%7 . As systematic investigations88 show, the primary attack of N-nucleophiles like ammonia and amines exclusively occurs at C1(2 of the triafulvene system. Further transformation strongly depends on N-substitution and triafulvene type. 

The ylide obtained from (methyl)triphenylphosphonium bromide reacts with morpholine derivatives 597 to give phosphonium salts 598 which upon treatment with -butyllithium are converted to new ylides 599. In a reaction with aldehydes, ylides 599 form iV-(l,3-disubstituted allyl)-morpholines 602 (Scheme 94) <1996AQ138>. Another less common nucleophile that can be used for substitution of the benzotriazolyl moiety in Af-(a-aminoalkyl)benzotriazoles is an adduct of iV-benzylthiazolium salt to an aldehyde which reacts with compounds 597 to produce adducts 600. Under the reaction conditions, refluxing in acetonitrile, salts 600 decompose to liberate aminoketones 601 <1996H(42)273>. 

Reaction of l-Methylpyrrole-2-acetonitrile 43 with 6 New Efficient Synthesis of Highly Substituted Indoles (Type-IV, 4a Model)... 

Reaction of Thiophene-2-acetonitrile 57 and Thiophene-3-acetonitrile 59 with 6 (Type IV, 4a and Type-V, 5a Model) An Efficient New General Synthesis of Highly Substituted Benzo[A thiophenes... 

Dipolar cycloaddition of 2,4-(trimethylsilyl)- and 2,4-(trimethylgermyl)-substituted thiophene-1,1-dioxides as well as silylated 2,2 -bithiophene-1,1-dioxides was investigated. It was shown that only the C(4)=C(5) double bond of 2,4-disubstituted thiophene-1,1-dioxides interacts with acetonitrile oxide to give thienoisoxazoline dioxides. Bithiophene derivatives were inactive or their reaction with nitrile oxide was accompanied by desilylation. Cycloaddition of benzonitrile oxide with all mentioned sulfones did not occur. The molecular structure of 3a-methyl-5.6a-bis(trimethylgermyl)-3a,6a-dihydrothieno 2.3-c/ isoxazole 4,4-dioxide was established by X-ray diffraction (263). ... 

Nucleophilic substitution reactions of halide anions in aprotic solvents are often accompanied by elimination reactions. For instance, reactions of secondary alkyl halides with potassium fluoride solubilized in acetonitrile with the aid of 18-crown-6 [3] give olefins as the main reaction product (Liotta and Harris, 1974). Similarly, the dicyclohexyl-18-crown-6 complex of potassium iodide acted exclusively as a base in its reaction with 2-bromo-octane in DMF (Sam and Simmons, 1974). The strongly basic character of weakly solvated fluoride has been exploited in peptide synthesis (Klausner and Chorev, 1977 Chorev and Klausner, 1976). It was shown that potassium fluoride solubilized... 

Copper-catalyzed monoaddition of hydrogen cyanide to conjugated alkenes proceeded very conveniently with 1,3-butadiene, but not with its methyl-substituted derivatives. The most efficient catalytic system consisted of cupric bromide associated to trichloroacetic acid, in acetonitrile at 79 °C. Under these conditions, 1,3-butadiene was converted mainly to (Z )-l-cyano-2-butene, in 68% yield. A few percents of (Z)-l-cyano-2-butene and 3-cyano-1-butene (3% and 4%, respectively) were also observed. Polymerization of the olefinic products was almost absent. The very high regioselectivity in favor of 1,4-addition of hydrogen cyanide contrasted markedly with the very low regioselectivity of acetic acid addition (vide supra). Methyl substituents on 1,3-butadiene decreased significantly the efficiency of the reaction. With isoprene and piperylene, the mononitrile yields were reduced... 

One-pot conversions of 2-hydroxy(acylbenzenes) with anhydrides or acid chlorides to produce coumarins [52-54] and flavones [54-58] under mild liquiddiquid or solidtliquid two-phase conditions via a Baker-Venkataraman type reaction (Scheme 6.19) are catalysed by quaternary ammonium salts. 3-Substituted coumarins are produced from salicylaldehyde and malonodinitrile, or substituted acetonitriles, in high yield (>85%) in a one-pot catalysed sequential aldol-type reaction and cycliza-tion in the absence of an added organic solvent [59]. When 2 -hydroxychalcones are reduced under catalytic two-phase conditions with sodium borohydride, 2,4-cis-flavan-4-ols are produced [60] (see Section 11.3). 

A kinetic smdy of the acylation of ethylenediamine with benzoyl chloride (110) in water-dioxane mixtures at pH 5-7 showed that the reaction involves mainly benzoylation of the monoprotonated form of ethylenediamine. Stopped-flow FT-IR spectroscopy has been used to study the amine-catalysed reactions of benzoyl chloride (110) with either butanol or phenol in dichloromethane at 0 °C. A large isotope effect was observed for butanol versus butanol-O-d, which is consistent with a general-base-catalysed mechanism. An overall reaction order of three and a negligible isotope effect for phenol versus phenol- /6 were observed and are consistent with either a base- or nucleophilic-catalysed mechanism. Mechanistic studies of the aminolysis of substituted phenylacetyl chlorides (111) in acetonitrile at —15 °C have revealed that reactions with anilines point to an associative iSN2 pathway. ... 

Kinetic studies of various systems have been carried out as follows the reaction of 2,2 -dichlorodiethyl sulfide and of 2-chloroethyl ethyl sulfide with diethylenetriamine and triethylamine in 2-methoxyethanol ° the catalysed reactions of substituted phenols with epichlorohydrin the reactions of para-substituted benzyl bromides with isoquinoline under high pressure the reactions of O-alkylisoureas with OH-acidic compounds [the actual system was N, N -dicyclohexyl-0-(l-methylheptyl)isourea with acetic acid] and tlie ring opening of isatin in aqueous binary mixtures of methanol and acetonitrile cosol vents. 

Reaction of (34) with the bidentate sulfur ligand isotrithionedithiol (H2dmit, (278)) produced a dianionic complex. The reaction of (278) in which the thiol groups were deprotected in situ prior to the substitution reaction with [TcNClJ in acetonitrile gave a 45% yield of [TcN(dmit)2] ... 

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