2382-96-9

Basic information

• Product Name: 2-Mercaptobenzoxazole
• Synonyms: BENZO[D]OXAZOLE-2-THIOL;BENZOXAZOLE-2-THIONE;BENZOOXAZOLE-2-THIOL;benzoxazole-2-thiol;2-Mercatobenzoxazole;2-MERCAPTOBENZOXAZOLE 95%;2-MERCAPTOBENZOXAZOLE, 98+%;2-Mercaptobenzoxazole,>97%
• CAS NO: 2382-96-9
• Molecular Formula: C₇H₅NOS
• Molecular Weight: 151.19
• EINECS: 219-191-9
• Product Categories: Isoxazoles, Oxadiazoles, Oxazoles;Oxazole&Isoxazole
• Mol File: 2382-96-9.mol
• Article Data: 77

Chemical Properties

• Melting Point: 192-195 °C(lit.)
• Boiling Point: 360°C (rough estimate)
• Flash Point: 103.4 °C
• Appearance: Beige/Crystalline Powder
• Density: 1.2170 (rough estimate)
• Vapor Pressure: 0.0258mmHg at 25°C
• Refractive Index: 1.5500 (estimate)
• Storage Temp.: Store below +30°C.
• PKA: 11.03±0.20(Predicted)
• Water Solubility: SLIGHTLY SOLUBLE
• BRN: 119483
• CAS DataBase Reference: 2-Mercaptobenzoxazole(CAS DataBase Reference)
• NIST Chemistry Reference: 2-Mercaptobenzoxazole(2382-96-9)
• EPA Substance Registry System: 2-Mercaptobenzoxazole(2382-96-9)

Safety Data

• Hazard Codes: Xi
• Statements: 36/37/38
• Safety Statements: 22-24/25-25-24-36-26
• WGK Germany: 3
• RTECS: DM4882500
• F: 13
• TSCA: Yes
• Hazardous Substances Data: 2382-96-9(Hazardous Substances Data)

Usage

Chemical Properties

beige crystalline powder

Uses

2-Mercaptobenzoxazole is used in the surface treatment of materials. It is utilized for protection of metals from corrosion.

Preparation

2-Mercaptobenzoxazole has already been described in 1876 by Dunner (Ber. 9, (1876) page 465). 2-Mercaptobenzoxazole and its derivatives are prepared by processes which are based in principle on the reaction between o-aminophenol and alkali metal alkylxanthates. The alkali metal alkylxanthate here can either be employed as such, or it can be produced in the reaction mixture itself from an alkali, a lower alkanol and carbon disulphide.https://patents.google.com/patent/US4677209A/en

Application

2-Mercaptobenzoxazole is a widely used organic scaffold in medicinal chemistry.2-Mercaptobenzoxazole and their derivatives are known to posses several biological activities such as antibacterial, antifungal, antiinflammatory, insecticidal and herbicidal. 4-0xo-thiazolidines have also played an important activities as analgesic, anti-HIV, antitubercular, anthelmentic, dye-stuffs, fluorescent and as a photosensitizer. The incorporation of 4-oxothiazolidine and their 5-arylidene moieties in 2-mercaptobenzoxazole frame work has been found to enhance the activity.

Reactions

2-Mercaptobenzoxazole with ethyl chloroacetate and anhydrous K2C03 in the presence of dry acetone was refluxed on water bath to give ethyl-2-(mercaptobenzoxazolo)acetate.

InChI:InChI=1/C7H5NOS/c10-7-8-5-3-1-2-4-6(5)9-7/h1-4H,(H,8,10)

Synthetic route

benzoxazole (273-53-0) → 2-sulfanyl-1,3-benzoxazole (2382-96-9)

Conditions	Yield
With 1.3-propanedithiol; potassium hydroxide In dimethyl sulfoxide at 130℃; for 12h; Inert atmosphere; Sealed tube;	92.6%
With 1.3-propanedithiol; dimethyl sulfoxide; potassium hydroxide at 130℃; for 12h; Inert atmosphere;	73%
With sulfur; 1,10-Phenanthroline; copper dichloride; sodium t-butanolate In N,N-dimethyl-formamide at 25℃; for 12h; Schlenk technique; Inert atmosphere;	67%

Thiram (137-26-8) + 2-amino-phenol (95-55-6) → 2-sulfanyl-1,3-benzoxazole (2382-96-9)

Conditions	Yield
In water at 80℃; Green chemistry;	92%
Stage #1: 2-amino-phenol With potassium carbonate In N,N-dimethyl-formamide for 0.0833333h; Stage #2: Thiram In N,N-dimethyl-formamide at 120℃; for 12h; Reagent/catalyst; Solvent; Temperature;	80%
In ethanol at 100℃; for 12h;	26%
In water at 80℃; for 3h;
In water at 80℃;

potassium ethyl xanthogenate (140-89-6) + 2-amino-phenol (95-55-6) → 2-sulfanyl-1,3-benzoxazole (2382-96-9)

Conditions	Yield
Stage #1: potassium ethyl xanthogenate; 2-amino-phenol In glycerol at 155℃; for 0.116667h; Microwave irradiation; Stage #2: With acetic acid In ethanol; water; glycerol pH=3 - 4;	91%
Stage #1: potassium ethyl xanthogenate; 2-amino-phenol In ethanol Reflux; Stage #2: With acetic acid In water pH=5;	52%
In ethanol Heating;
In ethanol; water Heating;
In ethanol

potassium isopropylxanthate (140-92-1) + 2-amino-phenol (95-55-6) → 2-sulfanyl-1,3-benzoxazole (2382-96-9)

Conditions	Yield
In N,N-dimethyl-formamide for 0.05h; Temperature; Time; Microwave irradiation;	90%

2-chloro-1,3-benzoxazole (615-18-9) → 2-hydroxybenzoxazole (59-49-4) + 2-sulfanyl-1,3-benzoxazole (2382-96-9)

Conditions	Yield
With sodium thiosulfate In ethanol; water Heating; Title compound not separated from byproducts;	A n/a B 86%

2-amino-phenol (95-55-6) + sodium dimethyldithiocarbamate (128-04-1) → 2-sulfanyl-1,3-benzoxazole (2382-96-9)

Conditions	Yield
With aluminum (III) chloride In water; N,N-dimethyl-formamide at 120℃; for 0.333333h; Temperature; Time;	83%

carbon disulfide (75-15-0) + 2-amino-phenol (95-55-6) → 2-sulfanyl-1,3-benzoxazole (2382-96-9)

Conditions	Yield
With potassium hydroxide In ethanol; water at 80℃; for 3h;	81%
With potassium hydroxide In ethanol; water for 3h; Heating;	78.2%
With potassium hydroxide In ethanol for 10h; Reflux;	77%

bis(2-benzoxazolyl) disulfide (36993-70-1) → 2-sulfanyl-1,3-benzoxazole (2382-96-9)

Conditions	Yield
With sodium citrate; titanium(III) chloride In ethanol; water; acetic acid pH 4.5 to 6.O;	76%

bis(2-benzoxazolyl) disulfide (36993-70-1) + (1'(R,S),3'-dihydroxy-2'(S,R)-ethylpropyl)benzene → 2-sulfanyl-1,3-benzoxazole (2382-96-9) + 2-(Benzooxazol-2-ylsulfanylmethyl)-1-phenyl-butan-1-ol

Conditions	Yield
With triphenylphosphine In tetrahydrofuran for 1h; Ambient temperature;	A n/a B 74%

bis(2-benzoxazolyl) disulfide (36993-70-1) + 2,2-Dibenzyl-butane-1,3-diol → 2-sulfanyl-1,3-benzoxazole (2382-96-9) + 2-(Benzooxazol-2-ylsulfanylmethyl)-2-benzyl-3-phenyl-propan-1-ol (200635-82-1)

Conditions	Yield
With triphenylphosphine In tetrahydrofuran rt., 1 h then reflux, 12 h;	A n/a B 72%

bis(2-benzoxazolyl) disulfide (36993-70-1) + (1S*,2R*)-2-Ethyl-1-phenylpropan-1,3-diol → 2-(butylthio)benzo[d]oxazole (22821-07-4) + 2-sulfanyl-1,3-benzoxazole (2382-96-9) + 2-(Benzooxazol-2-ylsulfanylmethyl)-1-phenyl-butan-1-ol

Conditions	Yield
With tributylphosphine In tetrahydrofuran for 1h; Ambient temperature;	A 10% B n/a C 65%

1.3-butanediol (18826-95-4, 107-88-0) + bis(2-benzoxazolyl) disulfide (36993-70-1) → 2-sulfanyl-1,3-benzoxazole (2382-96-9) + (±)-4-(1,3-benzoxazol-2-ylsulfanyl)butan-2-ol

Conditions	Yield
With triphenylphosphine In tetrahydrofuran for 1h; Ambient temperature;	A n/a B 58%

bis(2-benzoxazolyl) disulfide (36993-70-1) + syn-2-methyl-1-phenyl-1,3-propanediol (14366-91-7, 7087-77-6, 51451-31-1, 51451-32-2, 83909-75-5, 105497-76-5, 125760-89-6, 127379-92-4, 139068-60-3) → 2-(butylthio)benzo[d]oxazole (22821-07-4) + 2-sulfanyl-1,3-benzoxazole (2382-96-9) + 3-(Benzooxazol-2-ylsulfanyl)-2-methyl-1-phenyl-propan-1-ol

Conditions	Yield
With tributylphosphine In tetrahydrofuran for 1h; Ambient temperature;	A 5% B n/a C 54%

thiophosgene (463-71-8) + 2-amino-phenol (95-55-6) → 2-sulfanyl-1,3-benzoxazole (2382-96-9)

Conditions	Yield
In tetrahydrofuran at 0℃;	45%

1-phenyl-1,3-propanediol (4850-49-1) + bis(2-benzoxazolyl) disulfide (36993-70-1) → 2-(butylthio)benzo[d]oxazole (22821-07-4) + 2-sulfanyl-1,3-benzoxazole (2382-96-9) + 3-(Benzooxazol-2-ylsulfanyl)-1-phenyl-propan-1-ol

Conditions	Yield
With tributylphosphine In tetrahydrofuran for 1h; Ambient temperature;	A 4% B n/a C 38%

2-vinylthiobenzoxazole (22820-99-1) → acetaldehyde (75-07-0) + 2-sulfanyl-1,3-benzoxazole (2382-96-9)

Conditions	Yield
With hydrogenchloride; water In ethanol at 59.9℃; Kinetics; Rate constant; diff.temp. Eact diff.conc.of HCl;

potassium ethyldithiocarbamate (63467-57-2) + 2-amino-phenol (95-55-6) → 2-sulfanyl-1,3-benzoxazole (2382-96-9)

Conditions	Yield
Microwave irradiation;

carbon disulfide (75-15-0) + 2-amino-phenol (95-55-6) + Cyclopropylamine (765-30-0) → 2-sulfanyl-1,3-benzoxazole (2382-96-9)

Conditions	Yield
Stage #1: carbon disulfide; Cyclopropylamine In neat (no solvent) for 1h; Stage #2: 2-amino-phenol at 110℃; for 3h;

2-sulfanyl-1,3-benzoxazole (2382-96-9) + (1-decynyl)-[4-(trifluoromethyl)phenyl]-(tetrafluoroborato)-λ3-bromane → 1-decynyl 2-benzoxazolyl sulfide

Conditions	Yield
In dichloromethane at 0℃; for 1h;	100%

tetra(n-butyl)ammonium hydroxide (2052-49-5) + 2-sulfanyl-1,3-benzoxazole (2382-96-9) → tetra(n-butyl)ammonium benzoxazole-2-thiolate (75593-47-4)

Conditions	Yield
In methanol Inert atmosphere;	100%

2-sulfanyl-1,3-benzoxazole (2382-96-9) + 1-[(triisopropylsilyl)ethynyl]-1,2-benziodoxol-3(1H)-one → 2-(((triisopropylsilyl)ethynyl)thio)benzo[d]oxazole (1443746-62-0)

Conditions	Yield
Stage #1: 2-sulfanyl-1,3-benzoxazole With N,N,N',N'-tetramethylguanidine In tetrahydrofuran at 20℃; for 0.0833333h; Stage #2: 1-[(triisopropylsilyl)ethynyl]-1,2-benziodoxol-3(1H)-one In tetrahydrofuran at 20℃; for 0.0833333h; chemoselective reaction;	100%

2-sulfanyl-1,3-benzoxazole (2382-96-9) → bis(2-benzoxazolyl) disulfide (36993-70-1)

Conditions	Yield
With dihydrogen peroxide In water; ethyl acetate at 20℃; for 0.666667h; Green chemistry;	99%
With dihydrogen peroxide In ethyl acetate at 20℃; for 0.416667h; Solvent; Time;	98%
With dihydrogen peroxide at 20℃; for 0.166667h; Reagent/catalyst;	98%

2-sulfanyl-1,3-benzoxazole (2382-96-9) + C18H26FIO2*BF3 → 1-(2-benzoxazolylthio)-2-decanone

Conditions	Yield
With triethylamine In methanol at 20℃; for 3h;	99%

2-sulfanyl-1,3-benzoxazole (2382-96-9) + 4-(α-halogenophenylacetylamino)-1,5-dimethyl-2-phenyl-2,3-dihydro-1H-pyrazol-3-one → 2-(benzooxazol-2-ylsulfanyl)-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-2-phenyl-acetamide

Conditions	Yield
In ethanol for 4h; Heating;	99%

para-bromophenacyl bromide (99-73-0) + 2-sulfanyl-1,3-benzoxazole (2382-96-9) → 2-(benzo[d]oxazol-2-ylthio)-1-(4-bromophenyl)ethanone (13944-97-3)

Conditions	Yield
With zinc(II) oxide In neat (no solvent) at 25 - 30℃;	97%
Stage #1: 2-sulfanyl-1,3-benzoxazole With sodium carbonate In ethanol; water at 20℃; Stage #2: para-bromophenacyl bromide In ethanol; water at 20℃;	95%
(i) NaOMe, (ii) /BRN= 607604/; Multistep reaction;

benzoyl chloride (98-88-4) + 2-sulfanyl-1,3-benzoxazole (2382-96-9) → S-(benzoxazol-2-yl) thiobenzolate (17688-44-7)

Conditions	Yield
With potassium carbonate; 1-butyl-3-methylimidazolium Tetrafluoroborate at 50℃; for 2h;	97%
With triethylamine In tetrahydrofuran at -20℃; for 0.333333h;	90%
With triethylamine In tetrahydrofuran at 60℃; for 12h; Reagent/catalyst; Solvent; Temperature;	75%
With pyridine In tetrahydrofuran at 20℃; for 0.0833333h; Sonication;

1-Chloro-4-(chloromethyl)benzene (104-83-6) + 2-sulfanyl-1,3-benzoxazole (2382-96-9) → 2-(4-chlorobenzylsulfanyl)benzoxazole (101094-63-7) + bis(2-benzoxazolyl) disulfide (36993-70-1)

Conditions	Yield
With tetraethylammonium bromide In acetonitrile Ambient temperature; electrooxidation;	A 97% B n/a

chloroacetic acid ethyl ester (105-39-5) + 2-sulfanyl-1,3-benzoxazole (2382-96-9) → benzoxazol-2'-yl-mercaptoacetic acid ethyl ester (73824-25-6)

Conditions	Yield
In acetonitrile Ambient temperature; electrooxidation, supporting electrolyte Et4NBr;	97%
With tetraethylammonium bromide In acetonitrile electrolysis, Pt-cathode;	97%
With potassium carbonate; 3-butyl-1-methyl-1H-imidazol-3-ium hexafluorophosphate at 50℃; for 2h;	93%

2-sulfanyl-1,3-benzoxazole (2382-96-9) + 4,4'-Dimethoxybenzhydrol (728-87-0) → 2-(bis(4-methoxyphenyl)methylthio)benzo[d]oxazole (1384458-40-5)

Conditions	Yield
With N-cetyl-N-(4-sulfobutyl)pyrrolidinium trifluoromethanesulfonate In 1,2-dichloro-ethane at 20℃; for 2h; Schlenk technique;	97%
In benzene for 0.5h; Acidic conditions;

N-(benzenesulfonyl)-N-[(trifluoromethyl)sulfanyl]benzenesulfonamide + 2-sulfanyl-1,3-benzoxazole (2382-96-9) → 2-((trifluoromethyl)sulfinothioyl)benzo[d]oxazole

Conditions	Yield
In dichloromethane at 20℃; for 12h; Schlenk technique;	97%

Upstream product

• 64-17-5 ethanol 
• 140-89-6 potassium ethyl xanthogenate 
• 51-19-4 2-aminophenol hydrochloride 
• 110-89-4 piperidine 
• 70989-48-9 2-thioxo-benzooxazole-3-carboximidic acid p-tolyl ester 
• 19560-81-7 N-(3-Methylbutanoyl)benzoxazole-2-thione 
• 18826-95-4 1.3-butanediol 
• 36993-70-1 bis(2-benzoxazolyl) disulfide 
• 4850-49-1 1-phenyl-1,3-propanediol 
• 14366-91-7 syn-2-methyl-1-phenyl-1,3-propanediol 
• 1520-26-9 2-hydroxyphenylthiourea 
• 463-71-8 thiophosgene 
• 95-55-6 2-amino-phenol 
• 137-26-8 Thiram 

Downstream Products

• 76111-53-0 1-[2-(Benzooxazol-2-ylsulfanyl)-ethyl]-3-phenyl-thiourea 
• 2851-09-4 2-(piperidin-1-yl)-1,3-benzoxazole 
• 73384-54-0 anhydro-2-Hydroxy-4-oxo-3-phenylbenzo-4H-oxazolo<2,3-b><1,3>thiazinium hydroxide 
• 28291-80-7 2-(propylamino)benzoxazole 
• 87200-37-1 3--2-thiobenzoxazole 
• 73944-68-0 3-{[4-(4-Fluoro-phenoxy)-phenylamino]-methyl}-3H-benzooxazole-2-thione 
• 79834-49-4 1-benzoyl>-4-phenylpiperazine 
• 79834-50-7 {4-[(2-Thioxo-benzooxazol-3-ylmethyl)-amino]-phenyl}-(4-p-tolyl-piperazin-1-yl)-methanone 
• 79834-51-8 [4-(4-Chloro-phenyl)-piperazin-1-yl]-{4-[(2-thioxo-benzooxazol-3-ylmethyl)-amino]-phenyl}-methanone 
• 127895-04-9 Z-3-benzoxazole-3-phenyl-2-oxo-2-propanenitrile 
• 127895-06-1 3-[3H-Benzooxazol-(2E)-ylidene]-3-(4-chloro-phenyl)-2-oxo-propionitrile 
• 89114-27-2 2-(diphenylmethoxy)benzoxazole 
• 108176-87-0 3-<4-(morpholinomethyl)phenylaminomethyl>benzoxazolin-2-thione 
• 28291-86-3 2-n-Hexylamino-benzoxazol 

Relevant articles and documents

Photoaddition Reactions of Benzoxazole-2(3H)-thiones to Cycloalkenes and Heteroaromatics

Photoaddition reactions of benzoxazole-2-thiones 1 with cycloalkenes 2 and heteroaromatics 3 were examined. Irradiation of N-acylbenzoxazole-2-thiones 1a and 1b, and 3-(methoxycarbonyl)- and 3-(phenoxycarbonyl)benzoxazole-2(3H)-thiones (1f and 1h, resp.)

Green synthesis of therapeutically active 1,3,4-oxadiazoles as antioxidants, selective COX-2 inhibitors and their in silico studies

A modest, competent and green synthetic procedure for novel coumarinyl-1,3,4-oxadiazolyl-2-mercaptobenzoxazoles 8i-t has been reported. Analysis of the docked (PDB ID: 5IKR; A-Chain) poses of the compounds illustrated that they adopt identical conformations to the extremely selective COX-2 inhibitor. The biological outcomes as well as computational study suggested that the compounds originated to have elevated resemblance towards COX-2 enzyme than COX-1. The compounds 8i, 8l, 8q, 8r, 8s and 8t emerged as most potent and selective COX-2 inhibitors in contrast with Mefenamic acid. The selectivity index of 8l, 8n and 8r was respectively found to be 33.95, 20.25 and 24.98 which manifested their high selectivity against COX-2. Interestingly, the compounds which were active as COX-2 inhibitors were also active as antioxidant agents.

Microwave facilitated one-pot three component synthesis of coumarin-benzoxazole clubbed 1,2,3-triazoles: Antimicrobial evaluation, molecular docking and in silico ADME studies

4-((4-((Benzo[d]oxazol-2-ylthio)methyl)-1H-1,2,3-triazol-1-yl)methyl)-2H-chromen-2-ones 7k–z were synthesized by conventional as well as microwave irradiation method in order to obtain antimicrobial agents. The present green synthetic protocol explores facile work up procedure with excellent yields (82–92%) and purity. Docking studies exhibited strong binding interactions with enzyme N-myristoyl transferase (PDB ID: 4CAW) with excellent C-score values. Compounds 7k–z were screened for their in vitro antimicrobial activities. The compounds 7w and 7 y exhibited excellent antimicrobial results for all the tested microorganisms at MICs ranging from 3.12 to 6.25 μg/ml in comparison with the marketed drugs.