Elimination Of HCl Research Articles

Biotic and Abiotic Transformation Pathways of a Short-Chain Chlorinated Paraffin Congener, 1,2,5,6,9,10-C10H16Cl6, in a Rice Seedling Hydroponic Exposure System.

In this work, a typical congener of short-chain chlorinated paraffins (SCCPs) with six chlorine atoms (CP-4, 1,2,5,6,9,10-C10H16Cl6, 250 ng/mL) was selected to elaborate the comprehensive environmental transformation of SCCPs in rice seedling exposure system. CP-4 was quickly absorbed, translocated, and phytovolatilized by seedlings with a small quality of CP-4 (5.81-36.5 ng) being detected in the gas phase. Only 21.4 ± 1.6% of an initial amount (10,000 ng) of CP-4 remained in the exposure system at the end of exposure. Among the transformed CP-4, some were attributed to the degradation of the rhizosphere microorganism (9.1 ± 5.8%), root exudates (2.2 ± 4.2%), and abiotic transformation (3.0 ± 2.8%) that were proved by several transformation products found in the root exudate exposure groups and unplanted controls, and a majority was phytotransformed by rice seedlings. Here, 61 products were determined through complex transformation pathways, including multihydroxylation, -HCl elimination, dechlorination, acetylation, sulfation, glycosylation, and amide acid conjugation. The acetylated and amide acid conjugates of CPs were first observed. Phase I and Phase II phytometabolic reactions of CPs were found intertwining. These findings demonstrate that multiactive transformation reactions contribute to the overlook of CPs accumulated in plants and are helpful for the environmental and health risk assessments of SCCPs in agricultural plants.

Nonthermal plasma in the induction of polycondensation processes and intermolecular dehydrochlorination of chloroethanes in the liquid phase

AbstractThe nonthermal plasma treatment of 1,2‐dichloroethane, 1,1,2‐trichloroethane, and 1,1,2,2‐tetrachloroethane in the liquid phase leads to the formation of unsaturated chlorine derivatives of hydrocarbons, nanostructures, and hydrogen chloride. In the case of nonthermal plasma‐induced elimination of chloroethanes, the main products are: chloroethene from 1,2‐dichloroethane, 1,1‐dichloro‐, 1,2‐dichloroethene from trichloroethane, and trichloro‐ and tetrachlorethylenes from tetrachloroethane. Solid products are presented in the form of nanoscale carbon structures—multilayer nanotubes, carbon fibers, graphene layers, and others. Quantum‐chemical calculations show that the elimination of HCl under the nonthermal plasma treatment on chloroethanes occurs intermolecularly.

Stepwise Access of Emissive Ir(III) Complexes Bearing a Multi-Dentate Heteroaromatic Chelate: Fundamentals and Applications.

Three multi-dentate coordinated chelates LnH2 (n = 1, 2, and 3), comprising a linked 1-(pyridin-2-yl)ethylbenzene and one pyrazolyl pyridine unit and showing either tridentate or tetradentate coordination modes, are successfully designed and synthesized. Dinuclear Ir(III) complexes [Ir(κ4-Ln)(μ-Cl)]2 bearing tetradentate coordinated κ4-Ln chelate (2a, n = 1; 2b, n = 2; 2c, n = 3) were next obtained en route from the respective intermediate [Ir(κ3-LnH)Cl(μ-Cl)]2 bearing the tridentate coordinated κ3-LnH chelate (1a, n = 1; 1b, n = 2; 1c, n = 3). Next, mononuclear Ir(III) complexes Ir(κ4-Ln)(thd) (3a, n = 1; 3b, n = 2; 3c, n = 3) with the tetradentate chelate were obtained upon treatment of 2 with 2,2,6,6-tetramethyl-3,5-heptanedione (thd)H in the presence of K2CO3. Concurrently, methylation of 2c in the presence of MeI and nBu4NCl afforded tridentate Ir(κ3-L3HMe)Cl3 (4) and, next, can be converted to tetradentate Ir(κ4-L3Me)Cl2 (5) by further cyclometalation and HCl elimination in refluxing diethylene glycol monoethyl ether solution. The Ir(III) complexes 3a, 4, and 5 were unambiguously identified using spectroscopic methods, together with single-crystal X-ray structural analyses on Ir(III) derivatives 3a, 4, and 5. Their photophysical and ,electrochemical properties and device fabrication properties were also investigated and compared with results from theoretical studies.

A facile metal-free one-flask synthesis of multi-substituted furans via a BF3·Et2O mediated formal [4 + 1] reaction of 3-chloro-3-phenyldiazirines and α,β-alkenyl ketones.

A facile, efficient and metal free one-flask approach to diversely substituted furans from easily accessible 3-chloro-3-phenyldiazirines and α,β-alkenyl ketones is reported. This protocol integrates three steps of cyclopropanation, Cloke–Wilson rearrangement and elimination of HCl in one-flask to give products in moderate to good yields. It provides a metal and oxidant free approach to multi-substituted furans with the advantages of easy operation, mild reaction conditions and a broad scope of substrates.

Gas-phase synthesis and structure of thorium benzyne complexes.

The thorium benzyne complex (η2-C6H4)ThCl3- was synthesized in the gas phase through consecutive decarboxylation and dehydrochlorination from the (C6H5CO2)ThCl4- precursor upon collision-induced dissociation. Theoretical calculations suggest that (η2-C6H4)ThCl3- exhibits a metallacyclopropene structure with two polarized Th-Cbenzyne σ bonds. This procedure can be generally extended to the synthesis of a wide range of gas-phase thorium benzyne complexes.

Synthesis of phosphate and silane-based conjugated polymers derived from bis-azomethine: Photophysical and thermal characterization

Polyazomethines including phosphate and silane groups were studied in this work. In the first step, two Schiff base monomers, SBs with two hydroxyl functional groups were synthesized as a result of a condensation reaction between diamine and aldehyde. Then, Schiff bases were polymerized by HCl elimination between hydroxyl groups of the SBs and chlorine of phenyl dichlorophosphate (P) or dichlorodiethylsilane (Si) to obtain two different polyazomethines for each. FT-IR, 1H NMR, 13C NMR and thermal analysis were utilized to characterize the synthesized SBs, P-polyazomethines and Si-polyazomethines. The optical band gap values (Eg) of the synthesized P-polyazomethines and Si-polyazomethines were calculated using UV–Vis spectrophotometer. The study of solvent effects on the absorption of P-polyazomethines and Si-polyazomethines was also included into this work. Low band gaps of the synthesized polyazomethines could be evaluated as semi-conductive material for the production of electronic and optoelectronic materials. Photoluminescence (PL) measurements revealed that PP1 gave a greenish-yellow color emission upon excitation at blue light of 480 nm with a 16.2% of quantum yield although the response of SiP1 had white light emitting property. Besides, PP2 had multicolor emission property and SiP2 had white light emitting property. No obvious fluorescence changes were observed within 3600 s under the same conditions, serving as evidence of stability of PL emission of PP1, SiP1, PP2 and SiP2 to be steady along with wavelength of the exciting light. Thermal properties of the synthesized polyazomethines indicated that they were thermal stable materials up to 300 °C. The residual of P-polyazomethines and Si-polyazomethines was observed between 39.8% and 64.7% at 1000 °C.

Substitution of a nitro group by diazonium salts in σH-Adducts of carbanions to mono-nitrobenzenes. Formation of substituted azobenzenes and indazoles

σ H -Adducts formed at low temperature from nitrobenzene derivatives and carbanions stabilized by cyano, alkoxycarbonyl or sulfonyl groups react with benzenediazonium salts as nucleophiles, forming a new C–N bond preferentially at carbon atom bearing the nitro group. The so-formed intermediates eliminate HNO 2 molecule under action of base, yielding substituted azobenzenes. Adducts of secondary carbanions, stabilized by cyano or sulfonyl groups to the ortho positions of nitrobenzenes, cyclize in situ to substituted indazoles. Some ortho σ H -adducts of 1-chloroethyl phenyl sulfone carbanion add diazonium cations at meta position to the nitro group. In this case, the subsequent elimination of HCl leads to azo compounds retaining the nitro group in its original position.

Theoretical insight on the treatment of \u03b2-hexachlorocyclohexane waste through alkaline dehydrochlorination

The occurrence of 4.8–7.2 million tons of hexachlorocyclohexane (HCH) isomers stocked in dumpsites around the world constitutes a huge environmental and economical challenge because of their toxicity and persistence. Alkaline treatment of an HCH mixture in a dehydrochlorination reaction is hampered by the low reactivity of the β-HCH isomer (HCl elimination unavoidably occurring through syn H–C–C–Cl arrangements). More intriguingly, the preferential formation of 1,2,4-trichlorobenzene in the β-HCH dehydrochlorination reaction (despite the larger thermodynamical stability of the 1,3,5-isomer) has remained unexplained up to now, though several kinetic studies had been reported. In this paper, we firstly show a detailed Density Functional study on all paths for the hydroxide anion-induced elimination of β-HCH through a three-stage reaction mechanism (involving two types of reaction intermediates). We have now demonstrated that the first reaction intermediate can follow several alternative paths, the preferred route involving abstraction of the most acidic allylic hydrogen which leads to a second reaction intermediate yielding only 1,2,4-trichlorobenzene as the final reaction product. Our theoretical results allow explaining the available experimental data on the β-HCH dehydrochlorination reaction (rate-determining step, regioselectivity, instability of some reaction intermediates).

Homodinuclear RhI and IrI Complexes Derived from Imidazolium‐Benzimidazolates

AbstractThe reactions of [M(μ‐Cl)(COD)]2 (M=Rh, Ir) with the conjugated mesomeric betaines 2‐(3‐methyl‐1‐imidazolium)‐benzimidazolate (1aH), 2‐(3‐isopropyl‐1‐imidazolium)‐benzimidazolate (1bH) and 2‐(3‐tert‐butyl‐1‐imidazolium)‐benzimidazolate (1cH) in equilibrium with their carbenic tautomers 1’aH, 1’bH and 1’cH were investigated. In the case of 1aH and 1bH, the homodinuclear complexes [MCl(COD){M(μ‐1’a)(COD)}] and [MCl(COD){M(μ‐1’b)(COD)}] were obtained, whose anionic NHC ligand 1’a− or 1’b− bridges the metal centres in a κ1N : κ1N mode, while binding the M(COD) moiety in a C,N‐chelating mode. For M=Ir, [IrCl(COD){Ir(μ‐1’’b)(COD)}] containing the “abnormal” NHC isomer 1’’b− was observed as a side product. In the case of 1’cH, [{RhCl(COD)}2(μ‐1cH)] containing a κ1N : κ1N benzimidazolato ligand was obtained for M=Rh, while for M=Ir the reaction furnished [IrCl(COD){Ir(μ‐1’’c)(COD)}], which contains the anionic “abnormal” NHC ligand 1’’c−. This difference in behaviour is rationalised by the propensity of iridium(I) for oxidative addition, which in the present case involves a C−H bond of the dangling formamidium unit of [{IrCl(COD)}2(μ‐1cH)] to afford [IrICl(COD){IrIIIHCl(μ‐1’’c)(COD)}], followed by reductive elimination of HCl. The crystal structures of the new complexes were determined by single‐crystal X‐ray diffraction, except for [IrCl(COD){Ir(μ‐1’a)(COD)}], where by serendipity the closely related mononuclear complex [Ir(1’a)(COD)] was structurally characterised instead.

HCl elimination in the photolysis of chlorobenzene at 266 nm: An FT-IR spectroscopy and quantum chemical study

The photolysis of chlorobenzene (C6H5Cl) in the gas phase has been studied at 266 nm using repetitive scan FT-IR spectroscopy and density functional theory (DFT) to understand the degradation mechanism relevant to combustion and atmospheric chemistry. Following 266 nm photolysis of C6H5Cl, ro-vibrational lines were observed in the region 3060–2625 cm−1, at 3317.8/ 3262.7 cm−1 and 1346.2/1301.2 cm−1, and at 3341.2 and 1232.7 cm−1. These infrared features are assigned to the hydrochloric acid (HCl), acetylene (C2H2), and 1,3-butadiyne (C4H2), respectively. Identification of C2H2 and C4H2 but not expected HCl co-product ortho-benzyne (o-C6H4) indicates, possibly, o-C6H4 further degraded into C2H2 + C4H2. B3PW91/aug-cc-pVTZ and CBS-QB3 calculated potential energy surfaces for the possible degradation channels of C6H5Cl shows that HCl elimination and C–Cl bond fission are major degradation paths. Their experimental branching ratio was determined to be 1:1. The RRKM rate of HCl elimination of C6H5Cl at 266 nm was found to be 3.8 × 102 s−1 and compared with the HF elimination rate in C6H5F. The possible degradation mechanism is discussed.

Mechanism and Transformation Directions of 1,1,2 - trichloroethane in the Liquid Phase by Low-voltage Electrical Discharges

1,1,2-trichloroethane is transformed by the action of low-voltage (60 V DC) pulse discharge in the liquid medium in the nanostructure, cis-ClCH = CHCl, trans-ClCH = CHCl, CH2 = CCl2 and HCl. Conversion 1,1,2-trichloroethane 21 wt%, hydrogen chloride yield was 88.4 wt%, yield solid phase 11.6 wt%. The morphology and composition of solid phase products have been determined. According to energy dispersive X-ray spectroscopy, solid-phase products have an elemental composition, % atom: carbon — 90.5-94.2, chlorine — 1.35.4, oxygen — 3.1-4.5. The structures of 1,1-dichloroethylene and cis-, trans-1,2-dichloroethylene, as well as the isomer ratios were determined by 1H NMR. The relative content of isomers: cis-1,2-dichlorethylene 44%, trans-1,2-dichlorethylene 34%, 1,1-dichloroethylene 22%. Quantum-chemical modeling revealed the mechanism of formation of the obtained dichlorethylenes. According to the calculation results, 1,1,2-TCA is involved in the reaction in the triplet state. The difference in energy between the ground and excited states is 66.2 kcal/mol. The elimination of HCl is carried out by an activated chlorine atom generated during the transfer of 1,1,2-TCA under the action of electric discharges from the singlet state to the triplet state.

Photodissociation of CH2BrCHBrC(O)Cl at 248 nm: probing Br2 as the primary fragment using cavity ring-down spectroscopy.

The photodissociation of 2,3-dibromopropionyl chloride (CH2BrCHBrC(O)Cl, 2,3-DBPC) at 248 nm was carried out to study Br2 as the primary molecular product in the B3Π+0u ← X1Σ+g transition using cavity ring-down absorption spectroscopy. The rotational spectra (v'' = 0-2) were acquired and assigned with the aid of spectral simulation. It is verified that the obtained Br2 fragment is attributed to the one-photon dissociation of 2,3-DBPC and is free from contributions of secondary reactions. The vibrational ratio of the Br2 population of v(0):v(1):v(2) is equal to 1:(0.58 ± 0.12):(0.23 ± 0.09), corresponding to the Boltzmann vibrational temperature of 623 ± 38 K. The quantum yield of Br2 eliminated from 2,3-DBPC is estimated to be 0.09 ± 0.04. The dissociation pathways of 2,3-DBPC and its potential energy surfaces were calculated using density functional theory. By employing the CCSD(T)//M062X/6-31+g(d,p) level of theory, transition state barriers and corresponding reaction energies were calculated for the Br, Cl, Br2, BrCl, HBr and HCl elimination channels. The unimolecular rate constant for Br2 elimination was determined to be 2.09 × 105 s-1 using Rice-Ramsperger-Kassel-Marcus (RRKM) theory, thus explaining the small quantum yield of the Br2 channel.

Plastics in Heritage Collections: Poly(vinyl chloride) Degradation and Characterization

Museums and galleries house increasingly large collections of objects and contemporary art made of plastic materials, many of which undergo rapid material change. The main degradation processes of poly(vinyl chloride) (PVC) are elimination of HCl and plasticizer migration or leaching. This results in visible discolouration, stickiness and cracking. Degradation is known to be a multi-stage process that includes HCl elimination, formation of conjugated polyenes and cross-linking. Elimination of HCl begins due to structural irregularities (allylic and tertiary chlorides) and results in the formation of polyenes. When at least 7 conjugated double bonds are present, discolouration of PVC becomes visible. Non-invasive techniques, such as IR and Raman spectroscopy are used for polymer identification and plasticizer quantification. Plasticizer degradation and particularly the late stages of PVC degradation can be investigated using SEC, GC-MS, TGA and DSC. Studies in heritage collections have revealed that, apart from HCl, PVC objects emit 2-ethylhexanol and other volatile degradation products, however, there is currently no indication that HCl is emitted at usual indoor conditions. There seems to be a general lack of systematic research into PVC degradation at the conditions of storage and display, which could result in the development of dose-response functions and in the development of preventive conservation guidelines for the management of PVC collections.

Radical-promoted formation of dibenzofuran during combined UV-chlorine treatment on mono-substituted diphenyl ether

• UV-chlorine and UV treatments on BDE-1 produce dibenzofuran (DF)-type products. • Synergistic effect of UV and chlorine promotes the formation of DF-type products. • DF is formed via free radical reactions between ortho-carbon radicals and Cl or HO . • DF production decreases under high chlorine doses and strong irradiation. Polybrominated diphenyl ethers (PBDEs) are a group of flame retardants which are frequently detected in the aquatic environment. PBDEs would convert into intermediates during some natural or artificial processes. A simple PBDEs congener, 2-bromodiphenyl ether (BDE-1), was targeted, and its transformation characteristics during combined UV-chlorine treatment were investigated in this study. It was found that BDE-1 could rapidly transform in combined UV-chlorine process, and HO was the predominant radical that contributed to BDE-1 degradation in ultrapure water system. The formation of toxic dibenzofuran (DF) and 2-hydroxydibenzofuran (2-OH-DF) was significantly promoted in combined UV-chlorine treatment, whose total yield (2.78%) was 1.46 times to that in UV treatment alone. Radical scavenger tests revealed that enhanced formation of DF-type products in combined UV-chlorine treatment was attributed to radical reactions. Cl or HO generated from free available chlorine photolysis reacted with ortho-carbon radicals generated from BDE-1 photolysis, and produced intermediates 2-chlorodiphenyl ether (2-Cl-DE) or 2-phenoxyphenol (2-OH-DE), which underwent intramolecular elimination of HCl or H 2 O and formed DF and 2-OH-DF. The treatment with alkaline conditions, high chlorine doses and strong irradiation would be beneficial to the less formation of DF-type products. Besides, the matrix effects of ambient water also inhibited the formation of DF-type products. Overall, this work would provide an insight into the role of free radicals in dibenzofuran formation during combined UV-chlorine treatment on PBDEs and a scientific reference for optimizing operational parameters in the water treatment.

Unusual Acetonitrile Adduct Formed via Photolysis of 4′-Chloro-2-Hydroxybiphenyl in Aqueous Solution

In this work, 2,4'-dichlorobiphenyl (1) yielded 4'-chloro-2-hydroxybiphenyl (2) after photolysis in neutral acetonitrile aqueous (ACN-H2O) solutions. Ultrafast spectroscopic measurements and density functional theory (DFT) computations were performed for 2 in ACN and ACN-H2O (v/v, 1:1). These results were compared with previously published results for 2-hydroxybiphenyl (3). The counterparts 2 and 3 went through a singlet excited state intramolecular proton transfer (ESIPT) in ACN but behaved differently in ACN-H2O with a dehydrochlorination process occurring for 2 and an ESIPT taking place for 3. Computational results indicate that the phenol O-H bond elongates after photoexcitation to induce a concerted asynchronous process with the C-Cl bond increasing first followed by HCl elimination. A biradical intermediate (IM1) is then formed with some spin located at the phenyl 4'-C radical that appears to favor a hydrogen atom transfer (HAT) process and some spin located on phenoxyl that appears to prefer a subsequent •CH2CN radical rebound. The hydrogen bond promotes HCl elimination, while this is disfavored for ESIPT, making 4'-Cl extrusion the predominant process in ACN-H2O solutions. The mechanistic investigations have fundamental and significant implications for the understanding of polychlorinated biphenyl photolysis in an aqueous environment and hence the photodegradation of these kinds of pollutants in the natural environment.

Synthesis, Structure and Bonding Analysis of the Zwitterionic PPP-Pincer Complex (6-Ph2P-Ace-5-)2P(O)AuCl2

The reaction of (6-Ph2P-Ace-5-)2P(O)H with (tht)AuCl3 proceeds via elimination of tetrahydrothiophene (tht) and HCl, providing the zwitterionic PPP-pincer complex (6-Ph2P-Ace-5-)2P(O)AuCl2 (1) as yellow crystals. The molecular structure of 1 was established and studied by X-ray crystallography. The electronic structure was computationally analyzed using a comprehensive set of real-space bonding indicators derived from electron and electron-pair densities, providing insight into the relative contributions of covalent and non-covalent forces to the polar-covalent Au–Cl, Au–P, and P–O− bonds; the latter being one of the textbook cases for strongly polarized covalent interactions. Partial spatial complementarity between both bonding aspects is suggested by the electronic properties of the distinctively different Au–Cl bonds.

Phosphorus Silicon Compounds from the Reduction of MesP(H)SiCl2Ph/Carbene with and without Metal

MesP(H)SiCl2Ph (Mes = 2,4,6‐Me3C6H2) (7) with a reactive Si–Cl and P–H bond can easily be reduced by KC8 or alternatively by a carbene to give remarkable phosphorus silicon compounds. 7 is readily synthesized from the reaction of MesPH2 sequentially with nBuLi and PhSiCl3 in a 1:1:1 ratio. KC8 reduction of MesP(H)SiCl2Ph (7) in the presence of cyclic alkyl(amino) carbene (cAACMe) gives (MesPH)3SiPh (8) and cAAC‐stabilized Si2Ph2 (9). In addition, 9 might also be formed by the reduction of PhSiCl3 using KC8 in the presence of cAACMe. Treatment of MesP(H)SiCl2Ph (7) with IiPr2Me2 (IiPr2Me2 = 1,3‐diisopropyl‐4,5‐dimethylimidazol‐2‐ylidene) in a molar ratio of 1:2 results in HCl elimination as IiPr2Me2·HCl. The second equivalent of IiPr2Me2 was used to yield well‐defined phosphasilene (10) containing a Ph(Cl)Si=PMes moiety. This unit will gain much application in ligand design because the chlorine atom can readily be replaced by other substituents.

Biotransformation Mechanism of Pesticides by Cytochrome P450: A DFT Study on Dieldrin.

Pesticide biotransformation, especially by cytochrome P450 enzymes (CYPs), may produce metabolites with substantially altered toxicological and physicochemical profiles, which has drawn great attention as a basis for environmental risk assessment. CYPs are active in the metabolism of various reactions of pesticides, and there are potentially different short-lived oxidant species in CYPs (Compound I vs Compound 0), which make elucidating their biotransformation mechanism challenging. To facilitate this task, we performed density functional theory (DFT) calculations to explore the puzzling bifurcation pathways of dieldrin by CYPs. The results show that the two-oxidant mechanism does not work, while the bifurcation pathways are within the mechanistic framework of a two-state reactivity of Compound I. Specifically, 9-hydroxy-dieldrin as a hydroxylation product is formed via H-abstraction and essentially barrierless C-9 alkyl radical rebound in the doublet state; while 3-ketone-dieldrin as a dechlorination product is formed via H-abstraction, C-9 alkyl radical cyclization, and C-3 cyclized radical rebound in the quartet state followed by HCl elimination, originating from a significant barrier for C-9 alkyl radical rebound in the quartet state to provide this radical sufficient lifetime for cyclization. Thus, the ratio [dechlorination]/[hydroxylation] can be estimated as 1:35, consistent with the experimental findings. We envision that application of computational chemistry has a great potential in revealing the complex biotransformation mechanisms of pesticides.

Selenium chlorides in the domino process of the regiospecific allyl chlorination of betulin and diacetylbetulin

ABSTRACTThe interaction of betulin and diacetylbetulin with selenium chlorides occurs regiospecific with allylic chlorination of the substrate. Selenium chlorides are obtained by chlorination of selenium with sulfuryl chloride in the form of a mixture of SeCl2 and Se2Cl2. An intermediate product of the domino process, unsaturated allylic structure chloroselenide, was detected by 77Se and 1H NMR. The rate of conversion of selenide to allyl chloride was determined. According to the results of quantum-chemical calculations, in the reactions of betulin and diacetylbetulin with both SeCl2 and Se2Cl2, intermediates of the episelenuran type are formed in the first stage. Further, these intermediates are converted to unsaturated selenium chlorides by elimination of HCl. According to the calculation results, the final stage of the domino process – the formation of allyl chlorides is realized due to the catalytic action of SeCl2 in the elimination of selenium.

Acylation of 1,1-dichloroethylene by the arylalkanoic acid chlorides: synthesis of 4-chloro-2-naphthols

The acylation reactions of 1,1-dichloroethylene by the arylalkanoic acid chlorides were studied and a convenient approach to the synthesis of 4-chloro-2-naphthols was demonstrated. As starting materials for naphthols’ preparation, the available arylacetic acids, which are readily obtained by hydrolysis of the corresponding arylacetonitriles, were selected. It was found that the acylation reaction of 1,1-dichloroethylene by the arylacetic acid chlorides with acceptor substituents was completed by the formation of classical products of 4,4,4-trichloro-1-arylbutan-2-ones. The last ones had a tendency to readily cleave HCl and to convert into the corresponding 4,4-dichlorobut-3-ene-2-one derivatives. It should be noted that in the case of non-compliance with the reaction temperature conditions, the 4,4-dichlorobut-3-ene-2-one derivatives were found to be side products of the reaction. In contrast to the acceptor substituents, the corresponding 4-chloro-2-naphthols in high yields were formed in the reaction of unsubstituted phenylacetic or tolylacetic acid chlorides with 1,1-dichloroethylene. Obviously, in the case of donor substituents, the formed carbocation easily attacked the aromatic ring with the formation of an intermediate which was aromatized by the elimination of HCl. The reaction was exothermic. Minor resinous impurities were removed by recrystallization of naphthols from hexane. The lengthening of the carbon chain did not lead to the formation of the desired cyclic β -chloroketones. In particular, in the case of 3-phenylpropanoyl chloride, the main reaction product was 2,3-dihydroinden-1-one, which was a consequence of the intramolecular cyclization of the acylium ion. The product of 1,1-dichloroethylene acylation of 1,1-dichloro-5-phenylpent-1-en-3-one was found in a small amount. Attempts to use phenoxyacetic acid chlorides and 4-(4-methoxyphenoxy)butanoic acid chlorides as reagents led to the formation of the resinous products. In summary, a convenient way of synthesis of 4-chloro-2-naphthol derivatives from arylacetic acids was demonstrated and the general perspectives and limitations of the use of arylalkanoic acid chlorides in Friedel–Crafts acylation of 1,1-dichloroethylene for intramolecular cyclization to obtain cyclic β -chloroketones was discussed. Key words: arylacetic acids, 1,1-dichloroethylene, β -naphthol, intramolecular cyclization, Friedel–Crafts reaction.