2-Phenylbenzimidazole-5-sulfonic acid

• CAS: 27503-81-7
• Catalog Number: ACM27503817
• Category: Main Products
• Molecular Weight: 274.3
• Molecular Formula: C₁₃H₁₀N₂O₃S
• Synonyms: PARSOL HS;NEO HELIOPAN HYDRO;PHENYLBENZIMIDAZOLE SULFONIC ACID;LABOTEST-BB LT00454150;EUSOLEX 232;2-PHENYL-1H-BENZOIMIDAZOLE-5-SULFONIC ACID;2-PHENYL-1H-BENZO[D]IMIDAZOLE-5-SULFONIC ACID;2-PHENYL-5-BENZIMIDAZOLESULFONIC ACID
• IUPAC Name: 2-phenyl-3H-benzimidazole-5-sulfonicacid
• Canonical SMILES: C1=CC=C(C=C1)C2=NC3=C(N2)C=C(C=C3)S(=O)(=O)O
• InChI Key: UVCJGUGAGLDPAA-UHFFFAOYSA-N
• Melting Point: 300ºC
• Flash Point: >100ºC
• Density: 1.497g/cm³
• Appearance: white fine crystalline powder
• EC Number: 248-502-0
• Exact Mass: 274.04100
• Hazard Statements: Xi:Irritant
• Safety Description: S26-S36
• Stability: Stable under normal temperatures and pressures. May decompose when exposed to light.

Case Study

2-Phenylbenzimidazole-5-Sulfonic Acid for the Synthesis of Inclusion Complexes with Methyl-β-Cyclodextrin

Rajamohan R, et al. Journal of Molecular Liquids, 2023, 390(A), 123013.

2-Phenylbenzimidazole-5-sulfonic acid (PBS) was successfully used in the synthesis of inclusion complexes (IC) with methyl-β-cyclodextrin (MCD). The method involved ultrasonic homogenization, followed by freeze-drying, to generate water-soluble ICs. The reaction was carried out by adding PBS (0.045 M) dropwise to an equimolar MCD solution, ensuring a 1:1 molar ratio of host-guest components. The mixture was continuously heated to 60 °C while stirring with a magnetic field to promote complex formation. The resulting PBS:MCD IC displayed excellent solubility, confirmed by the clear appearance of the solution. Freeze-drying the complex at -82 °C for 48 hours yielded white powders, which were identified as the final inclusion complex. This method is notably energy-efficient, offering significant savings in both time and resources, making it suitable for large-scale applications. The PBS:MCD inclusion complex could have potential uses in drug delivery systems or other pharmaceutical formulations due to its enhanced solubility and stability.

Study of the photodegradation mechanism of 2-phenylbenzimidazole-5-sulfonic acid (PBSA)

Ji, Yuefei, et al. Water Research 47.15 (2013): 5865-5875.

The photodegradation mechanisms and pathways of the sunscreen 2-phenylbenzimidazole-5-sulfonic acid (PBSA) under artificial solar irradiation were investigated with the aim of evaluating the potential of photolysis as a transformation mechanism in aquatic environments. The quantum yield of direct photolysis of PBSA in pH 6.8 buffer solution under irradiation with a filtered mercury lamp was 2.70 10. Laser flash photolysis (LFP) experiments confirmed the involvement of PBSA radical cations (PBSA) in the direct photolysis process. Acidic or alkaline conditions favored the direct photolysis of PBSA in aqueous solution. Only at higher levels of photosensitizers (e.g., NO > 2 mM) could indirect photolysis surpass direct photolysis and become the dominant process for PBSA decay. Therefore, direct photolysis may be the main loss pathway of PBSA in surface waters depleted of natural sunlight irradiation. The direct photolysis pathway of PBSA includes desulfonation and benzimidazole ring cleavage, which may be initiated by the excited triplet state (PBSA*) and radical cation (PBSA).
Steady-state photolysis experiments were performed in a homemade photochemical reactor equipped with a 125 W high-pressure mercury lamp installed in a borosilicate immersion well. The HPK lamp was turned on for 10 min in advance for stabilization, and then 50 mL of 2-phenylbenzimidazole-5-sulfonic acid (PBSA) solution (10 mM) was pipetted into a Pyrex reactor (1/4 5 cm inner diameter, H 15 cm, V 150 mL), and the reactor was placed in the photoreactor for irradiation. The light intensity (300-400 nm) at the center of the reaction solution was measured by a photometer and was approximately 3.3 mW cm. A radiometer was used to ensure that the irradiance did not change significantly during the photolysis process. The temperature was maintained at 20 ± 1 °C by cooling water circulation. A dark control wrapped in aluminum foil was also performed under the same conditions. The effect of solution pH on direct photolysis was examined in buffer solutions of different pH values (10 mM phosphate buffer or 10 mM borate buffer). Deoxygenated and aerated conditions were achieved by bubbling Ar and O into the solution to investigate the effect of dissolved oxygen on direct photolysis. The HOradical scavenger 2-propanol was used to verify the involvement of H2O2 in PBSA photolysis under acidic pH conditions. The triplet quencher sorbic acid (2.5 mM) was also used to confirm whether the triplet state of PBSA was involved in PBSA direct photolysis.

Degradation and mineralization of 2-phenylbenzimidazole-5-sulfonic acid

Abdelraheem, Wael HM, et al. Journal of hazardous materials 282 (2015): 233-240.

A UV-254 nm/H2O advanced oxidation process (AOP) was investigated to degrade the model UV absorber compound 2-phenylbenzimidazole-5-sulfonic acid (PBSA) and the structurally similar compound 1H-benzimidazole-2-sulfonic acid (BSA). At 4.0 mM [H2O], 190 min of UV irradiation resulted in complete removal of 40.0 M of the parent PBSA with a 25% reduction in TOC; SO was formed and reached a maximum level, while nitrogen release in the form of NH was much lower (approximately 50%) at 190 min. Increasing [H2O] in the range of 0-4.0 mM significantly enhanced sulfate removal, with a slight inhibitory effect in the range of 4.0-12.0 mM. Faster and earlier ammonia formation was observed at higher [H2O].
Degradation experiments were performed in a Pyrex glass dish photochemical reactor with a quartz cover. Typically, a total solution volume of 10 mL was added to the reactor, which was then covered with a quartz cover and placed in the apparatus under constant temperature and stirring conditions. Even at longer irradiation times, the solution pH did not change significantly (e.g., the pH of 40.0 M 2-phenylbenzimidazole-5-sulfonic acid (PBSA) and 1H-benzimidazole-2-sulfonic acid (BSA) decreased from 4.62 and 4.48 to 4.05 and 3.83, respectively, using 190 min of UV irradiation and 4.0 mM [H2O]). No buffer was added for pH adjustment in this study, except that buffer had strong interference with IC detection of other inorganic anions. No quencher was added to the samples before HPLC quantification or TOC measurement, as there was no significant degradation of PBSA or BSA under H2O-only conditions.

Quantum chemistry of 2-phenylbenzimidazole-5-sulfonic acid

Zhang, Siyu, et al. Environmental science & technology 44.19 (2010): 7484-7490.

For the ecological risk assessment of a large and growing number of chemical pollutants, the development of computational methods to screen or predict their environmental photodegradation behavior is of great significance. In this study, a density functional theory (DFT)-based computational method was developed to predict and evaluate the photodegradation behavior and impact of water components, using 2-phenylbenzimidazole-5-sulfonic acid (PBSA) from sunscreen and personal care products as a model compound. The energy and electron transfer reactions of excited state PBSA (PBSA*) with O and water components were evaluated. The computational results showed that PBSA* can photogenerate O and O·, triplet excited state humic acid/fulvic acid analogs cannot be photodegraded, and anions (Cl, Br, and HCO) cannot chemically quench PBSA* or its radical cations. Experiments using simulated sunlight confirmed that PBSA photodegrades through direct and autosensitized mechanisms involving O·. The photodegradation is pH-dependent. Direct and autosensitized photodegradation are inhibited by fulvic acid. The main photodegradation products were identified and the pathways were elucidated. These results demonstrate that DFT-based computational methods can be used to assess the environmental photochemical fate of organic pollutants.
A rotating photoreactor and a quartz tube containing a 2-phenylbenzimidazole-5-sulfonic acid (PBSA) solution were used. The light source was a water-cooled 500 W high-pressure mercury lamp equipped with a 365 nm filter to simulate the UVA and UVB parts of sunlight. A dark control was included in each batch, and no PBSA loss was observed in the dark. The effect of Ore was examined in aerated or unsaturated solutions. The role of ROS was examined in aerated solutions using D2O, hematoporphyrin dihydrochloride (HPDHC), and p-benzoquinone (BQ). The pH dependence of the photolysis kinetics was examined in pure water adjusted with H2SO4 and NaOH solutions. The photolysis quantum yield was determined at pH 1, 7, and 14 using p-nitroanisole/pyridine (PNA/pyr) as a chemical photometer.

Corrosion-resistant composite coating based on 2-phenylbenzimidazole-5-sulfonic acid

Ding, Caiyou, et al. Molecules 28.13 (2023): 5199.

In this study, ZnAl layered double hydroxide (ZnAl-LDH) was functionalized with 2-phenylbenzimidazole-5-sulfonic acid (PBSA), and ZnAl-PBSA-LDH was prepared by a simple one-step method. The electrochemical impedance spectroscopy (EIS) results of the solution phase showed that ZnAl-PBSA-LDH had excellent corrosion inhibition performance. Subsequently, 0.6 wt.% ZnAl-PBSALDH with shielding and activity inhibition effects was incorporated into waterborne epoxy resin (WEP) to prepare a high-performance anti-corrosion coating (6-ZPL/WEP). EIS tests showed that the 6-ZPL/WEP coating still maintained a high low-frequency impedance modulus (|Z|) after immersion for 30 days, which was nearly two orders of magnitude higher than that of the blank coating. These results indicate that ZnAl-PBSA-LDH can effectively improve the corrosion resistance of WEP coatings. Therefore, this study provides new insights into the application of layered double hydroxides (LDH) in the field of corrosion protection.
Preparation of ZnAl-LDH loaded with 2-phenylbenzimidazole-5-sulfonic acid (PBSA) The preparation of ZnAl-PBSA-LDH needs to be completed under a nitrogen atmosphere. First, at a temperature of 35 ° C, under vigorous stirring, a quantitative ZnCl solution and AlCl·6HO solution were slowly added to the flask through a constant pressure dropping funnel. Subsequently, 100 mL of PBSA solution was slowly dripped into the mixed solution. The pH of the solution was then adjusted to 9 with sodium hydroxide. The mixed solution was stirred for 2 hours, and then the white precipitate was aged at a temperature of 70 ° C for 24 hours. Subsequently, the mixture was filtered to remove all the supernatant. The obtained sample was washed several times with degassed distilled water and then dried in a vacuum oven at 80 ° C.

Custom Q&A

What is the molecular formula of Ensulizole?

The molecular formula of Ensulizole is C13H10N2O3S.

What is the molecular weight of Ensulizole?

The molecular weight of Ensulizole is 274.30 g/mol.

When was Ensulizole created?

Ensulizole was created on July 12, 2005.

What is another name for Ensulizole?

Another name for Ensulizole is 2-Phenylbenzimidazole-5-sulfonic acid.

What is the IUPAC name of Ensulizole?

The IUPAC name of Ensulizole is 2-phenyl-3H-benzimidazole-5-sulfonic acid.

What is the InChIKey of Ensulizole?

The InChIKey of Ensulizole is UVCJGUGAGLDPAA-UHFFFAOYSA-N.

What is the Canonical SMILES of Ensulizole?

The Canonical SMILES of Ensulizole is C1=CC=C(C=C1)C2=NC3=C(N2)C=C(C=C3)S(=O)(=O)O.

What is the CAS number of Ensulizole?

The CAS number of Ensulizole is 27503-81-7.

What is the XLogP3 value of Ensulizole?

The XLogP3 value of Ensulizole is 2.

What is the maximum approved concentration of Ensulizole according to the FDA?

According to the FDA, the maximal approved concentration of Ensulizole is 148 mM.

Synthetic Use

Upstream Synthesis Route 1

• 93-58-3

• 27503-81-7

Reference: [1]Current Patent Assignee: MERCK KGAA - US5473079, 1995, A

Downstream Synthesis Route 1

• 27503-81-7

• 27503-82-8

Reference: [1]Current Patent Assignee: ALUMEND LLC - US2005/113288, 2005, A1
Location in patent: Page/Page column 15; Sheet 5
[2]Current Patent Assignee: Novartis (w/o Sandoz); NOVARTIS AG - US2012/28969, 2012, A1
Location in patent: Page/Page column 52

* For details of the synthesis route, please refer to the original source to ensure accuracy.