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Light irradiation of a PtCl62- solution in acetone affords a ?-acetonyl complex of platinum(IV), 2-.Prolonged irradiation yields CH3COCH2Cl and PtCl42-.The signals of a platinum(III) complex and CH3COCH2-radical are detected in the ESR spectrum of the frozen solution of PtCl62- in acetone irradiated at 77 K.The proposed mechanism of the reaction involves electron transfer from the enol tautomer of acetone to PtCl62-.

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Relative kinetics of the reactions of OH radicals and Cl atoms with 3-chloro-2-methyl-1-propene has been studied for the first time at 298-K and 1-atm by GC-FID. Rate coefficients are found to be (in cm3-molecule-1-s-1): k1 (OH-+-CH2-=-C(CH3)CH2Cl)-=-(3.23-±-0.35)-×-10-11, k2 (Cl-+-CH2-=-C(CH3)CH2Cl)-=-(2.10-±-0.78)-×-10-10 with uncertainties representing-±-2σ. Product identification under atmospheric conditions was performed by solid phase microextraction/GC-MS for OH reaction. Chloropropanone was identified as the main degradation product in accordance with the decomposition of the 1,2-hydroxy alcoxy radical formed. Additionally, reactivity trends and atmospheric implications are discussed.

The invention relates to a new method for synthesizing thiabendazole. Acetone and chlorine are taken as starting materials to synthesize chloroacetone, chloroacetone not subjected to separation can directly react with thiocarbamide to obtain 2-Amino-4-methylthiazole which is subjected to diazotization to obtain 4-methylthiazole, and 4-methylthiazole is oxidized to produce 4-thiazolecarboxylic acid, and finally, 4-thiazolecarboxylic acid reacts with o-phenylenediamine to obtain the target object thiabendazole. The thiabendazole is a broad-spectrum anthelmintic, can repel roundworms, hookworms, whipworms, pinworms, strongyloises stercoralis and trichinization, is also a broad-spectrum efficient disinfectant and is widely used as a fruit fresh-keeping agent and a bactericidal mildew inhibitor in various fields over the past decade in China.

Commercial two-step processes to convert glycerol into epichlorohydrin are more benign compared to the predominant industrial route starting from propene in terms of materials requirements and CO2 emissions. Still, the use of alkali hydroxides in stoichiometric amounts in the second reaction, i.e., the dehydrochlorination of the dichloropropanol intermediate, leads to the formation of large amounts of salt wastes, thus limiting the greenness of the technology. Here, we show for the first time that the latter transformation can be selectively conducted in the gas phase in the presence of a heterogeneous hydrotalcite-derived mixed oxide of Al and Mg. Upon reaction, the lamellar solid is rehydrated to a hydrotalcite-like compound, which can effectively activate the alcoholic group of dichloropropanol owing to its strong Br?nsted basic character and moderately high surface area. In-depth characterisation of the porous, compositional, structural and acid/base properties demonstrates that the HCl formed during the reaction causes the progressive exchange of interlayer OH groups by Cl atoms, thus gradually diminishing the reactivity of the material. Facile calcination restores the original mixed oxide structure and is shown to enable three equivalent consecutive reaction runs. Since the HCl evolved along with water upon regeneration can be recycled in the first step of the process, i.e., glycerol hydrochlorination, our approach paves the way for a waste-free and more atom efficient biobased epichlorohydrin production process.

The rate constants and products for the reactions of atomic Cl and O3 molecule with 3-methyl-3-buten-2-one (MBO332) and 3-methyl-3-penten-2-one (MPO332) were determined in a 100 L Teflon chamber at 293 ± 1 K and atmospheric pressure. For MBO332 and MPO332, the rate constants measured with atomic Cl were (2.38 ± 0.26) × 10-10 and (3.00 ± 0.34) × 10-10 cm3 molecule-1 s-1 using the relative rate method. Using the absolute rate method, the rate constants with O3 measured were (1.18 ± 0.21) × 10-17 and (4.07 ± 0.45) × 10-17 cm3 molecule-1 s-1. The products of these reactions were investigated by the proton-transfer-reaction mass spectrum (PTR-MS). The results indicated that the major products observed in the atomic Cl reaction were formaldehyde together with chloroacetone for MBO332, and acetaldehyde and CH3C(O)C(O)Cl for MPO332. For O3 reactions, butanedione and formaldehyde were the main products of MBO332, while butanedione and acetaldehyde were the main products of MPO332. Possible reaction mechanisms were proposed and discussed and the atmospheric implications of these reactions were also discussed.

Diazoacetone reacts with methyl acrylate in the presence of anhydrous GaCl3 to give isomeric methyl 2-acetylcyclopropanecarboxylates rather than pyrazolines obtained from diazo esters or by noncatalytic reactions. In a similar reaction, diazoacetophenone yields methyl 2-benzoylcyclopropanecarboxylates, benzoylmethyl acrylate, and benzoylmethyl 2-benzoylcyclopropanecarboxylate via partial transesterification. Addition of an equimolar amount of GaCl3 to diazoacetone in the system CH2Cl2-HCl-H2O unexpectedly produces 4,5-dimethylfuran-3(2H)-one and 1,1'-oxybis(propan-2-one).

An important chemical sink for organic peroxy radicals (RO2) in the troposphere is reaction with hydroperoxy radicals (HO2). Although this reaction is typically assumed to form hydroperoxides as the major products (R1a), acetyl peroxy radicals and acetonyl peroxy radicals have been shown to undergo other reactions (R1b) and (R1c) with substantial branching ratios: RO2 + HO2 → ROOH + O2 (R1a), RO 2 + HO2 → ROH + O3 (R1b), RO2 + HO2 → RO + OH + O2 (R1c). Theoretical work suggests that reactions (R1b) and (R1c) may be a general feature of acyl peroxy and α-carbonyl peroxy radicals. In this work, branching ratios for R1a-R1c were derived for six carbonyl-containing peroxy radicals: C2H 5C(O)O2, C3H7C(O)O2, CH3C(O)CH2O2, CH3C(O)CH(O 2)CH3, CH2ClCH(O2)C(O)CH 3, and CH2ClC(CH3)(O2)CHO. Branching ratios for reactions of Cl-atoms with butanal, butanone, methacrolein, and methyl vinyl ketone were also measured as a part of this work. Product yields were determined using a combination of long path Fourier transform infrared spectroscopy, high performance liquid chromatography with fluorescence detection, gas chromatography with flame ionization detection, and gas chromatography-mass spectrometry. The following branching ratios were determined: C2H5C(O)O2, YR1a = 0.35 ± 0.1, YR1b = 0.25 ± 0.1, and YR1c = 0.4 ± 0.1; C3H7C(O)O2, YR1a = 0.24 ± 0.15, YR1b = 0.29 ± 0.1, and YR1c = 0.47 ± 0.15; CH3C(O)CH2O2, Y R1a = 0.75 ± 0.13, YR1b = 0, and YR1c = 0.25 ± 0.13; CH3C(O)CH(O2)CH3, Y R1a = 0.42 ± 0.1, YR1b = 0, and YR1c = 0.58 ± 0.1; CH2ClC(CH3)(O2)CHO, Y R1a = 0.2 ± 0.2, YR1b = 0, and YR1c = 0.8 ± 0.2; and CH2ClCH(O2)C(O)CH3, YR1a = 0.2 ± 0.1, YR1b = 0, and YR1c = 0.8 ± 0.2. The results give insights into possible mechanisms for cycling of OH radicals in the atmosphere.

To ensure the quasi-irreversibility of the oxidation of alcohols coupled with the reduction of ketones in a hydrogen-transfer (HT) fashion, stoichiometric amounts of a-halo carbonyl compounds have been employed as hydrogen acceptors. The reason that these substrates lead to quasi-quantitative conversions has been tacitly attributed to both thermodynamic and kinetic effects. To provide a clear rationale for this behavior, we investigate herein the redox equilibrium of a selected series of ketones and 2-propanol by undertaking a study that combines experimental and theoretical approaches. First, the activity of the (R)-specific alcohol dehydrogenase from Lactobacillus brevis (LBADH) with these substrates was studied. The docking of acetophenone/(R)-l-phenyethanol and a-chloroacetophenone/(S)-2-chloro- lphenylethanol in the active site of the enzyme confirms that there seems to be no structural reason for the lack of reactivity of halohydrins. This assumption is confirmed by the fact that the corresponding aluminum-catalyzed Meerwein-Ponndorf-Verley-Oppenauer (MPVO) reactions afford similar conversions to those obtained with LBADH, showing that the observed reactivity is independent of the catalyst employed. While the initial rates of the enzymatic reductions and the IR v(C=0) values contradict the general belief that electron-withdrawing groups increase the electrophilicity of the carbonyl group, the calculated βG values of the isodesmic redox transformations of these series of ketones/alcohols with 2-propanol/acetone support the thermodynamic control of the reaction. As a result, a general method to predict the degree of conversion obtained in the HT-reduction process of a given ketone based on the IR absorption band of the carbonyl group is proposed, and a strategy to achieve the HT oxidation of halohydrins is also shown.

The oxidation of some aliphatic alcohols by [bis(trifluoroacetoxy)iodo] benzene (TFAIB) in aqueous acetic acid solution leads to the formation of the corresponding carbonyl compounds. The reaction is first order in TFAIB and a Michaelis-Menten kinetics is obtained with respect to the alcohols. The reaction shows a first order dependence on hydrogen ions. The oxidation of [1,1- 2H2]ethanol and [2-2H]propan-2-ol exhibits the presence of a substantial primary kinetic isotope effect at 298 K (k H/kD = 3.64 and 3.89 respectively). The rate of disproportionation of the intermediate is susceptible to both polar and steric effects of the substituents. A suitable mechanism has also been proposed.

Manufacture of dichloropropanol Process for manufacturing dichloropropa nol wherein a glycerol-based product comprising at least one diol containi ng at least 3 carbon atoms other than 1,2- propanediol, is reacted with a chlorinati ng agent, and of products derived from dichloropropanol such as ep ichlorohydrin and epoxy resins. No figure.

Using Pd(CF3;CO2)2/(S,S)-f-binaphane as the catalyst, an efficient enantioselective synthesis of cyclic sulfamidates was developed via asymmetric hydrogenation of the corresponding cyclic imines in 2,2,2-trifluoroethanol at room temperature with high enantioselectivities (up to 99% ee).

Heterocycles, e.g., epoxides, are carbonylated at low pressure with high percentage conversion to cyclic, ring expanded products using the catalyst where L is tetrahydrofuran (THF).

A readily prepared bimetallic catalyst is capable of effecting epoxide carbonylation to produce β-lactones at substantially lower CO pressures than previously reported catalyst systems. A functionally diverse array of β-lactones is produced in excellent yields at CO pressures as low as 1 atm. This procedure allows for epoxide carbonylation on a multigram scale without the requirement of specialized, high-pressure equipment.

Butyltriphenylphosphonium dichromate (BTPPD) oxidizes aliphatic alcohols to the corresponding carbonyl compounds. The reaction is first order in BTPPD. The reaction exhibits a second order dependence each on the alcohol and hydrogen ions. The oxidation of deuteriated ethanol and 2-propanol indicates the presence of a substantial primary kinetic isotope effect. The reaction has been studied in nineteen organic solvents and the solvent effect was analyzed using multiparametric equations. It is observed that the cation-solvating power plays a major role in the reaction. The rate of oxidation shows excellent correlation with the polar and steric substituent constants. Suitable mechanisms have been proposed.

The TiCl4-mediated substitution of 3-chloro-3,5- bis(chloromethyl)-5-methyl-1,2,4-trioxolane (1) with 1-(trimethylsilyloxy) cyclopentene (4), 2-methyl-1-(trimethylsilyloxy)propene (6) and allyltrimethylsilane (12) gave the corresponding 2-oxocy

A method is provided for synthesizing acylamides, useful as protectant for cultivated plants. A benzoxazine, such as 3,4-dihydro-3-methyl-2H-1,4-benzoxazine, is made in a stepwise manner by initially forming an o-nitrophenoxyketone by reacting a haloketone and a nitrophenol. The o-nitrophenoxyketone is hydrogenated to form the corresponding benzoxazine, which is thereafter acylated with an acylhalide to produce the acylamide, such as 4-dichloroacetyl-3,4-dichloroacetyl-3,4-dihydro-3-methyl-2H-1,4-benzoxazine.

The present invention provides compounds of formula I: or a pharmaceutically acceptable derivative o thereof, wherein A, B, Ra, R1, R2, R3, and R4 are as described in the specification. These compounds are inhibitors of protein kinase, particularly inhibitors of JNK, a mammalian protein kinase involved cell proliferation, cell death and response to extracellular stimuli; Lck and Src kinase. The invention also relates to methods for producing these inhibitors. The invention also provides pharmaceutical compositions comprising the inhibitors of the invention and methods of utilizing those compositions in the treatment and prevention of various disorders.

The invention concerns a method for preparing a compound of formula (1) wherein: A represents naphthyl or phenyl optionally substituted; and Ar1, Ar2independently represent a saturated or aromatic carbocyclic group, optionally substituted.

The rate coefficients and mechanisms of the reaction of Cl-atoms with a series of unsaturated hydrocarbons under atmospheric conditions were studied. It was observed the product yielded from both trans-2-butene and 1-butene were found to be oxygen dependent. The results showed that the variation of the product yielded with O2 in the case of 1-butene resulted from competitive reaction pathways for the two β-chlorobutoxy radicals involved in the oxidation.

The carbonyl group of 1,3-dichloro-2-propanone was reduced selectively through hydrogen transfer from 2-butanol over MgO, SiO2*Al2O3, Al2O3, and ZrO2. It is suggested that the reaction is promoted by either base or acid site of the catalysts.

The rate constants and the products of the reactions between atomic chlorine and acrolein, methachlorine, and methyl vinyl ketone were determined. Rate coefficients for the reactions of chlorine with acrolein and with methyl vinyl ketone were slightly dependent at 1.6 and 760 torr, although the rate coefficients at 1.6 torr were a factor of only ～ 2 smaller than the values obtained at 1 atm. The reaction between Cl atoms and methacrolein in synthetic air and 1 atm yielded chloroacetone, formaldehyde, CO, and HCl. Between Cl atoms and acrolein, the products of reaction were HCl, chloroacetaldehyde, formaldehyde, and CO. For the reaction between Cl atoms and methyl vinyl ketone, the products were chloroacetaldehyde, formaldehyde, and CO. Branching ratios for abstraction (the fraction of reactions occurring by abstraction relative to the sum of addition and abstraction processes) were 0.22 for acrolein, 0.18 for methacrolein, and 0.03 for methyl vinyl ketone. Vast quantities of isoprene were converted to methacrolein in the atmosphere, and several channels of oxidation following attack by chlorine on methacrolein led to CO formation, with an overall yield of ～ 0.75.

Oxidation of fourteen aliphatic alcohols by benzyltrimethylammonium chlorobromate (BTMACB) in aqueous acetic acid leads to the formation of the corresponding carbonyl compounds. The reaction is first order each in BTMACB and the alcohol. The reaction failed to induce the polymerization of acrylonitrile. There is no effect of benzyltrimethylammonium chloride or potassium bromide on the reaction rate. The proposed reactive oxidizing species is chlorobromate ion. The oxidation of [1,1-2]ethanol and [2-]propan-2-ol exhibited a substantial kinetic isotope effect. The effect of solvent composition indicated that the rate increases with an increase in the polarity of the solvent. The reaction is subject to both the polar and steric effects of the substituents. A mechanism involving transfer of a hydride ion from the alcohol to the oxidant has been proposed.

The oxidation of aliphatic alcohols by substituted oxo(salen)manganese(V) (H2salen = N,N'- Bissalicylideneethylenediamine) complexes, in acetonitrile, leads to the formation of the corresponding carbonyl compounds. The reaction is first order each in alcohol and Mn(V) complex. The oxidation of [1,1-2H2]ethanol and [2-2H]propan-2-ol exhibits substantial kinetic isotope effects. The rate of oxidation of twelve alcohols by four Mn(V) complexes have been determined. The oxidation is susceptible to both the polar and steric effects of the substituent in the alcohol molecule. The reaction constants are negative. The rate of reduction of the substituted Mn(V) complexes shows an excellent correlation in terms of Hammett equation with positive reaction constants. The reactivity-selectivity principle (RSP) is obeyed in this reaction. The validity of RSP is verified by Exner's mathematical procedure. Suitable mechanisms have been discussed.

The oxidation of some aliphatic alcohols by quinolinium fluorochromate (QFC) in dimethyl sulfoxide leads to the formation of corresponding carbonyl compounds. The reaction is first order with respect to QFC. The reaction exhibited Michaelis-Menten type kinetics with respect to the alcohol. The reaction is catalyzed by hydrogen ions. The hydrogen-ion dependence has the form: kobs = a+b[H+]. The oxidation of [1,1-2H2]ethanol (MeCD2OH) exhibits a substantial primary kinetic isotope effect. The reaction has been studied in nineteen different organic solvents. The solvent effect was analyzed using Taft's and Swain's multiparametric equations. The rate of disproportionation of the complex is susceptible to both polar and steric effects of the substituents. A suitable mechanism has been proposed.

Mono- or polycarboxylic acid esters are prepared by reacting a salt of such carboxylic acid with an organic halocompound, e.g., a (cyclo)alkyl, (cyclo)alkenyl, aryl or aralkyl halide, in an aqueous reaction medium, in the presence of a catalytically effective amount of a phase transfer catalyst, for example an onium salt.

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Oxidation of secondary alcohols by hexamethylenetetramine-bromine (HABR) in acetic acid leads to the formation of the corresponding ketones. The reaction is first order with respect to HABR. Michaelis-Menten type kinetics were observed with respect to alcohols. The oxidation of benzhydrol-α-d exhibited a substantial kinetic isotope effect (kH/kD = 3.16 at 298 K). The reaction was subjected to both polar and steric effects of the substituents. A mechanism involving transfer of a hydride ion from the alcohol to the oxidant has been proposed.

Diazomethyl ketones (2-diazoethanones) were reacted with the Vilsmeier reagent ((chloromethylidene)dimethylammonium chloride) to yield α-diazo-β-oxoaldehydes and chloromethyl ketones. 2′,4′-Dimethoxy-α-diazoacetophenone gave 2-chloro-1-(2,4-dimethoxyphenyl)-3-(dimethylamino)prop-2-en-1-one (5) in addition to the expected products. Phenyldiazomethanes gave the corresponding benzyl chlorides but not the (phenyl)diazoacetaldehydes even at temperatures as low as -60°. The diazo-transfer reactions of phenylacetaldehydes and 2-azido-1-ethylpyridin-1-ium tetrafluoroborate also did not yield the expected(phenyl)diazoacetaldehydes.

Substitution of 3-chloro-3,5-bis(chloromethyl)-5-methyl-1,2,4-trioxolane (3) with allyl alcohol gave the corresponding diastereomeric allyloxy-substituted ozonides 4, which were converted into diozonides 7 by ozone treatment. Substitutions of 3 with ethanediol or with 1,3-propanediol gave the corresponding hydroxyalkoxy-substituted ozonides 8, 14, which were oxidized to the corresponding aldehydes 10, 16. Reaction of 3,5-dichloro-3,5-bis(chloromethyl)-1,2,4-trioxolane (1a) with ethanediol gave the corresponding bis(hydroxy)-substituted ozonide 19 as well as a bicyclic ozonide 18 by reaction of 1a with ethanediol in a ratio of 1:1. Wiley-VCH Verlag GmbH, 1997.

The oxidation of secondary alcohols by bis(2,2'-bipyridyl) copper(II) permanganate (BBCP) in aqueous acetic acid leads to the formation of corresponding ketones. The reaction is first order with respect to BBCP and the alcohols. The reaction rates have been determined at different temperatures and the activation parameters have also been calculated. The reaction rate increases with increase in the concentration of H+ ions. The oxidation of benzhydrol-α-d exhibits a substantial kinetic isotope effect (kH/kD = 5.34). With increase in the amount of acetic acid in the solvent mixture of acetic acid and water, the rate increases. Addition of 2,2'-bipyridine and acrylonitrile has no effect on the rate. Suitable mechanism has been proposed.

The oxidation of secondary alcohols by pyridinium hydrobromide perbromide (PHPB) in aqueous acetic acid leads to the formation of the corresponding ketones. The reaction is first order with respect to PHPB and the alcohols. The reaction rates have been determined at different temperatures and the activation parameters calculated. The oxidation of benzhydrol-α-d exhibited a substantial kinetic isotope effect (kH/kD = 4.83). With an increase in the amount of acetic acid in the solvent mixture of acetic acid and water, the rate increases. Addition of pyridinium hydrobromide and acrylonitrile has no effect on the rate. Suitable mechanisms have been proposed.

Reactions of substituted 3-chloro- (2a-4a) and 3,5-dichloro-1,2,4-trioxolanes (9a, 10a) with AgBF4 in the presence of LiF gave the corresponding fluoro-substituted ozonides (2b - 4b and 9b and 10b).Substitutions of some of these chlorinated ozonides by the methoxy and by the acetoxy groups, and of 3,6-dichloro-3,6-dimethyl-1,2,4,5-tetroxane (22a) with the acetoxy group have been achieved too.

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Ozonolyses of acyclic olefins containing 1,2-dichloro-substituted (4a,b) and monochloro-substituted double bonds (7a, b, 12) as well as two (4a, b, 7a, b) or one halomethyl group (12) attached to the double bond afford the corresponding ozonides as the first representatives of monocyclic chlorinated ozonides.Their stability decreases in order 5a, 5b > 8a, 8b > 13. - Key Words: Ozonides/ 1,2,4-Trioxolanes, 3-chloro-, 3,5-dichloro- / Polyethylene

The four isomers of chloroepoxypropane have been prepared, and their relative reactivities with triphenyltin haydride have been determined.The three α-chloroepoxypropanes react at a much slower rate than does epichlorohydrin, the only β-chloro epoxide of the four.The nature of the increased reactivity for the β-chloro epoxides has been investigated by studying two pair of diastereomeric β-chloro epoxides, and a single acyclic β-chloro ether.The results are discussed in terms of the inductive, and stereoelectronic effects of the epoxide.

Copper metal and such gem-dichlorides as α,α-dichloro acid esters, 1a-e, diphenyldichloromethane, 2, benzal chloride, 3, 1,1-dichloro-2-butene, 5, and carbon tetrachloride, 6, were found to produce copper carbenoid intermediates via α,α-elimination of dichlorides along with the formation of CuCl2(DMSO)2.Thus, 1 and 2 gave substituted olefins via a carbenoid coupling reaction.From 5 and 6, reaction products via the oxygen abstraction from DMSO were produced together with dimethyl sulfide; 3 and 4 were found to cause both types of reactions.The carbenoid intermediates formed from 1 did not cause cyclopropanation reaction with cyclohexene in contrast to the conventional carbalkoxy carbenoid generated by a decomposition reaction of ethyl diazoacetate.Also the carbenoid coupling reaction was completely inhibited by the addition of triphenylphosphine, which was contrastive to the formation of phosphonium ylide with a carbenoid from ethyl diazoacetate.

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The composition of the products and the kinetic parameters were determined for the liquid-phase thermolysis of 2-chloro-1-propanol at 130-160 deg C and of 1,3-dichloro-2-propanol and 2,3-dichloro-1-propanol at 180-200 deg C.The intramolecular dehydrochlorination of the 1,2-chlorohydrins is based on a process of the E1 type with the formation of an enol, which rearranges to the carbonyl compound according to the El'tekov rule; the isomerization of 1,2-chlorohydrins catalyzed by hydrogen chloride and their reaction with hydrogen chloride take place through the formation of a chloronium cation, which is attacked in the first case by a water molecule and in the second by the chloride ion.

The transmetalation reaction of trimethylaluminum with the palladium chloride dimer Pd2Cl2(μ-dppm)2 (1) (dppm = bis(diphenylphosphino)methane) at -78 deg C gave an intermediate, Pd2ClMe(μ-dppm)2 (2), which disproportionated at ca. 10 deg C to yield the trans-face-to-face palladium dimer Pd2Cl2Me2(μ-dppm)2 (3) and a palladium dimer Pd2Cl2(μ-CH2)(μ-dppm)2 (5).The use of excess trimethylaluminum at -40 deg C gave the dimethyl complex, Pd2Me2(μ-dppm)2 (7).When 2 and 7 were protonated, a stable A-frame chloro-bridged dimer + (6) and a hydride-bidged dimer + (8) were obtained.Warming 6 in solution to ambient temperature caused the reductive elimination of methane; 8 lost methane and ethane at ambient temperatures.Both reductive eliminations were strictly intramolecular as determined by crossover experiments.The reaction of 6 with CO (1 atm) at -20 deg C first gave a carbonyl-bridged complex + (10) that rearranged to the acyl complex + (11) and then on warming eliminated acetaldehyde.The carbonylation of 8 (1 atm) proceeded stepwise to give first the mono- and then the diacyl complexes.The diacyl complex + (13) underwent the reductive elimination of acetaldehyde at ambient temperatures.

1-Chloro-2-alkanones (α-chloromethylketones) were conveniently prepared by chlorination of methyl β-ketoesters and subsequent demethoxycarbonylation using 50percent sulfuric acid.

Rate constants are reported for all of the major steps followed in the chlorination of acetone, including the chlorination of mono- and 1,1-dichloroacetone, the chlorination of hydroxyacetone, the chlorination and hydroxide-catalyzed rearrangement of 1,1-dihydroxyacetone, and the haloform cleavage of trichloroacetone. pKa values are reported for hydroxyacetone and monochloroacetone.Rate constants for the hydrolyses of chloroacetone and 1,1-dichloroacetone are reported; these reactions are probably not SN2 displacements but proceed by addition of hydroxide and intramolecular displacement.

Room temperature reaction of simple aliphatic ketones with an aqueous solution of TiCl3 leads to mono-oxoalkylthalium(III) derivatives followed by formation of selectively α-monochlorinated ketones.

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The simple enols -2-hydroxypropene, -3-chloro-2-hydroxypropene, 2,2-dichlorovinyl alcohol, and hydroxypropadiene have been generated from reactive precursors in solution and characterized by NMR spectroscopy.The kinetics of ketonization of 3-chloro-2-hydroxypropene, hydroxypropadiene, and of the previously described (Z)-prop-1-en-1-ol and 2-methylprop-1-en-1-ol were studied by UV spectrophotometry at 15 deg C.It was found that k0 varied with pH according to the equation k0 = kH2O + (kH+10-pH) + (kHO-KW)/10-pH and values of kH2O, kH+, and kHO- were evaluated for these four enols.Solvent isotope effects, kH+/kD+, were determined and the acid-catalyzed ketonization of 3-chloro-2-hydroxypropene and 2-methylprop-1-en-1-ol were studied in water-Me2SO4 mixtures.The kinetics of the acid-catalyzed hydrolyses of the methyl enol ethers that correspond to these enols were also investigated.It is concluded that the kinetic results were best explained by concerted mechanism for the hydronium ion catalyzed and spontaneous ketonization and by a stepwise mechanism for the hydroxide ion catalyzed ketonization.

The main product of the oxidation of secondary alcohol by ceric ammonium nitrate is the corresponding ketone.The reaction is of first-order with respect to the oxidant but exhibit a Michaelis-Menten type kinetics with respect to the alcohol.The formation constants of the alcohol-CeIV complex and its thermodynamic parameters have been calculated.The rate of decomposition of the complex and the activation parameters have also been evaluated.The rates of decomposition of the complex correlate with Taft's ?* values with a low negative reaction constant.The oxidation induced polymerisation of acrylonitrile.The retardation of rate with increasing acidity has been explained on the formation of kinetically inactive protonated alcohol.The protonated constants for the various alcohol have been calculated.The presence of a small primary kinetic isotope effect, kH/kD = 2.3, confirms that the rate-determining step involves a C-H bond rupture in a non-symmetrical transition state.

Trichloroisocyanuric acid is an effective reagent for the chlorination of ketones in the alpha position.

Kinetics of oxidation of aliphatic, aryl aliphatic and cyclic ketones by trichloroisocyanuric acid has been studied in aqueous acetic acid medium in the presence of HClO4.The reaction is acid-catalysed exhibiting first order dependence each in and and zero order dependence in .This supports the acid catalyzed enolisation of ketone as the rate-determining step and reaction between enol and oxidant as the fast step.Alkoxyacetophenones exhibit an anomalous behaviour in that there is first order dependence on the halogenating agent.This has been attributed to the fact that in the case of alkoxyacetophenones the rates of halogenation may be less than the rates of enolisation.The decrease in dielectric constant of the medium slightly enhances the rate of reaction.The ρ? relationship in the case of acetophenones is linear with ρ as -0.2 indicating the simultaneous operation of equilibrium protonation of ketone and deprotonation of conjugate acid.Arrhenius activation parameters have been computed.A plausible mechanism consistent with the experimental results is postulated.

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