95-88-5

Usage

Uses

Used in Cosmetics and Personal Care Industry:
4-Chlororesorcinol is used as a hair dye formulation agent in the cosmetics and personal care industry. It is specifically utilized in permanent hair coloring systems, where the color is produced inside the hair fiber through a highly controlled interaction of ingredients.
Used in Pharmaceutical Industry:
4-Chlororesorcinol is also used in the synthesis of a series of six coumarin compounds that carry halogen and trifluoromethyl groups. These synthesized compounds exhibit antifungal activities, making them valuable in the development of pharmaceutical products for treating fungal infections.

Preparation

4-Chlororesorcinol is synthesized by reacting resorcinol with dichlorosulfuryl. Resorcinol and diethyl ether were mixed, heated to reflux with stirring, and dichlorosulfuryl was slowly added dropwise. The temperature was then raised to 60°C for 1 h. After recovery of ether, atmospheric distillation is carried out, the distillate is subjected to vacuum distillation again, and the 131°C (0.8-0.93kPa) or 160-164°C (4.0kPa) fractions are collected to obtain the finished 4-chlororesorcinol.

Flammability and Explosibility

Nonflammable

Safety

4-chlororesorcinol is classified as a toxic substance and exposure to high concentration of 4-chlororesorcinol could cause several health issues including, skin irritation, serious eye irritation, and other hazards.The safety of 4-Chlororesorcinol has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. The CIR Expert Panel evaluated the scientific data and concluded that 4-Chlororesorcinol was safe in hair dye formulations.The CIR Expert Panel concluded that the scientific data suggested that 4-Chlororesorcinol can be safely used in hair dye products. Subchronic dermal exposure to a hair dye product containing 2% 4-Chlororesorcinol produced no evidence of compound-induced toxicity. At the same concentration, no development effects, no evidence of reproductive toxicity, and no carcinogenic effects were seen following dermal exposure. Likewise, 4-Chlororesorcinol was not mutagenic in either a micronucleus or in bacteria, nor did it induce aneuploidy in fungus cells. A 2.5% solution was not a dermal irritant or an ocular irritant.

Purification Methods

Crystallise it from boiling CCl4 (10g/L, charcoal) and dry it in air. [Beilstein 6 II 818.] IRRITANT.

InChI:InChI=1/C6H5ClO2/c7-5-2-1-4(8)3-6(5)9/h1-3,8-9H

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Relevant academic research and scientific papers

One-pot synthesis of sulfur doped activated carbon as a superior metal-free catalyst for the adsorption and catalytic oxidation of aqueous organics

Synthesis of S-doped activated carbon with a well-developed porous structure and enhanced catalytic activity has been extensively investigated because of its great potential applications in various fields. Here, we report a facile one-pot thermal process

Effects of Na2SO4 or NaCl on sonochemical degradation of phenolic compounds in an aqueous solution under Ar: Positive and negative effects induced by the presence of salts

Abstract Sonochemical degradation of 4-chlorophenol, phenol, catechol and resorcinol was studied under Ar at 200 kHz in the absence and presence of Na2SO4 or NaCl. The rates of sonochemical degradation in the absence of salts decreased in the order 4-chlorophenol > phenol > catechol > resorcinol and this order was in good agreement with the order of log P (partition coefficient) value of each phenolic compound. The effects of salts on the rates of sonochemical degradation consisted of no effect or slight negative or positive effects. We discussed these unclear results based on two viewpoints: one was based on the changes in pseudo hydrophobicity and/or diffusion behavior of phenolic compounds and the other was based on the changes in solubility of Ar gas. The measured log P value of each phenolic compound slightly increased with increasing salt concentration. In addition, the dynamic surface tension for 4-chlorophenol aqueous solution in the absence and presence of Na2SO4 or NaCl suggested that phenolic compounds more easily accumulated at the interface region of bubbles at higher salt concentration. These results indicated that the rates of sonochemical degradation should be enhanced by the addition of salts. On the other hand, the calculated Ar gas solubility was confirmed to decrease with increasing salt concentration. The yield of H2O2 formed in the presence of Na2SO4 or NaCl decreased with increasing salt concentration. These results suggested that sonochemical efficiency decreased with decreasing gas amount in aqueous solution: a negative effect of salts was observed. Because negative and positive effects were induced simultaneously, we concluded that the effects of salts on the rates of sonochemical degradation of phenolic compounds became unclear. The products formed from sonochemical degradation of 4-chlorophenol were also characterized by HPLC analysis. The formation of phenol and 4-chloro-1,3-dihydroxy benzene was confirmed and these concentrations were affected by the presence of salts.

Practical regioselective halogenation of vinylogous esters: Synthesis of differentiated mono-haloresorcinols and polyhalogenated resorcinols

A practical and efficient method for the direct, regioselective conversion of vinylogous esters to haloresorcinols is reported. Control of the reaction conditions enables synthesis of either the 4- or 6-haloresorcinol isomers from a common precursor with excellent regiocontrol and high yield. The generality and functional group tolerance of this novel protocol is demonstrated. The utility of this methodology to access polyhaloresorcinols is also reported. These methods create useful functionalized building blocks for further synthetic applications.

Candida antarctica lipase B-catalyzed regioselective deacylation of dihydroxybenzenes acylated at both phenolic hydroxy groups

Candida antarctica lipase B proved to be highly active in the deacylation of substituted hydroquinones and resorcinols acylated at both phenolic hydroxy groups. The deacylation reactions were much faster than the corresponding direct acylations of these dihydroxybenzenes catalyzed by the same lipase. More importantly, they took place generally in a markedly regioselective manner: the acyloxy group remote from the substituent was preferentially cleaved. The main or exclusive products obtained were the regioisomers of those produced through the direct acylation of the dihydroxybenzenes. In the case of alkyl-substituted hydroquinone derivatives, the regioselectivity increased with an increase in the bulk of the substituent. In the case of 4-substituted diacylated resorcinols, the 3-O-monoacyl derivatives were obtained generally as the sole products. Quite interestingly, some secondary alcohols proved to act as better acyl acceptors than the corresponding primary alcohols in these enzymatic deacylations.

Charge transfer and photocatalytic activity in CuO/TiO2 nanoparticle heterojunctions synthesised through a rapid, one-pot, microwave solvothermal route

Rapid charge carrier recombination is a major limiting factor over efficiency in many semiconductor photocatalysts. To address this, copper(II) oxide/titanium dioxide (CuO/TiO2) heterojunctions were synthesised through a novel, rapid solvothermal microwave procedure using a low-cost copper precursor and commercial P25 TiO2, taking as little as five minutes to synthesise well-defined CuO nanoparticles onto the host TiO2, achieving an intimate contact. The resultant composites encompass pure CuO particles of approximately 6-7 nm diameter, confirmed by means of high resolution transmission electron microscopy and X-ray photoelectron spectroscopy analysis. Photoelectrochemical water splitting was enhanced by nearly 2 times using the junction, whilst ≈1.6 times enhancement in the photocatalytic mineralisation of a model organic pollutant 2,4-dichlorophenoxyacetic acid (2,4-D) was observed. Furthermore, we studied the initial decomposition mechanism of 2,4-D by means of GC-MS analysis. The increase in catalytic activity, investigated by impedance analysis (Mott-Schottky plots) and photoluminescence spectra, is attributed to photoelectron transfer from the more negative conduction band (CB) of TiO2 to CuO, leaving the photohole on TiO2 to take part in oxidation reactions. This strategy allows for in situ charge separation which facilitates superior photocatalytic activity for both pollutant degradation and water splitting.

Secondary alcohols act as better nucleophiles than primary alcohols in the lipase-catalyzed regioselective deacylation of dihydroxybenzenes acylated at both phenolic hydroxyls

Candida antarctica lipase B (CAL-B) was found to be highly regioselective as well as active in the deacylation of resorcinols and hydroquinones acylated at both phenolic hydroxyls. Contrary to expectation, secondary alcohols acted as better nucleophiles than primary alcohols in these enzymatic deacylations.

Degradation of p-chlorophenol by γ-radiolysis: Radiolytic intermediates and theoretical calculations

Radiolysis of p-chlorophenol (p-CP) was investigated through experiments and theoretical calculations. Its radiolytic intermediate products, i.e., phenol, hydroquinone, 4-chlororesorcinol, and 4-chloropyrocatechol, were identified using their mass spectra through a GC/MS system. Three transition states and a prereaction complex of the reaction between hydroxyl radical and p-CP were found from the density functional theory (DFT) study. Both the experimental and calculation results demonstrate that the main p-CP degradation pathway was the formation of 4-chloropyrocatechol. Copyright

Selective halogenation of aromatics by dimethyldioxirane and halogen ions

The oxidation of halogen anions by dimethyldioxirane (DMD) produced reactive species which led, in acidic media, to the halogenation of activated aromatic rings. The reaction can be efficiently controlled to obtain selective and mixed halogenated species.

Aqueous chlorination kinetics and mechanism of substituted dihydroxybenzenes

The initial chlorination kinetics of several substituted dihydroxybenzenes, including chlorinated resorcinol compounds, was studied over the pH range of 2-12 at 22 °C. For each of the resorcinol substrates, the apparent chlorination rates are a minimum in the pH range of 3-6 and a maximum at pH values between 8-11. A mechanism that involves the reaction of HOCl with ArX(OH)2, ArX(OH)O-, and ArX(O-)2, and an acid-catalyzed pathway at pH 2, ArX(OH)O-, and ArX(O-)2, and an acid-catalyzed pathway at pH 4 was proposed to explain this pH dependence. Over natural water pH conditions, the reactions of HOCl with the anion and dianion forms of resorcinol groups are the most important. Although the intrinsic reactivity of HOCl with resorcinol substrates decreases with the extent of chlorine substitution on aromatic ring, the apparent reactivity of HOCl increases for more chlorinated resorcinols. In the presence of excess HOCl, monochloro- and dichloro resorcinol intermediates, therefore, should not accumulate when resorcinol groups undergo chlorine substitution. Linear free energy relationships for the reactivity of HOCl with resorcinols and phenols were developed. The sequential chlorination kinetics of resorcinol up to trichlororesorcinol can now be modeled.

SYNTHESIS OF ANALOGUES OF PRECOCENES CONTAINING 6-CHLORO- OR 6-TERT-BUTYL SUBSTITUENTS

The synthesis of benzopyran compounds (XIV and XVI), analogues of precocenes (I and II) containing 6-chloro- or 6-tert-butyl substituents, is described .