5-METHOXY-2-MERCAPTOBENZIMIDAZOLE

PRODUCT IDENTIFICATION
CAS NO. 37052-78-1

5-METHOXY-2-MERCAPTOBENZIMIDAZOLE
EINECS NO. 253-326-2
FORMULA C8H8N2OS
MOL WT. 180.22
H.S. CODE

 
TOXICITY

 
SYNONYMS 5-Methoxy-2-benzimidazolethiol;
5-Methoxybenzimidazole-2-thiol; 2-Mercapto-5-methoxybenzimidazole; 1,3-Dihydro-5-methoxy-2H-benzimidazole-2-thione;
SMILES  

CLASSIFICATION

 

PHYSICAL AND CHEMICAL PROPERTIES
PHYSICAL STATE White to slightly beige powder
MELTING POINT

255 C
BOILING POINT  
SPECIFIC GRAVITY

 
SOLUBILITY IN WATER Insoluble
AUTOIGNITION  
NFPA RATINGS  
FLASH POINT  
STABILITY Stable under normal temperatures and conditions

GENERAL DESCRIPTION AND APPLICATIONS
Benzimidazole is a white to slightly beige solid; melting at 172 C, boils at 360 C,  slightly soluble in water, soluble in ethanol. It is a dicyclic compound having imidazole ring (containing two nitrogen atoms at nonadjacent positions) fused to benzene. Benzimidazole and its derivatives are used in organic synthesis and vermicides or fungicides as they inhibit the action of certain microorganisms. Benzimidazole structure is the nucleus in some drugs such as proton pump inhibitors and anthelmintic agents. 5-Methoxy-2-benzimidazolethiol is used as an intermediate for organic compounds and pharmaceuticals ( especially for Antiulcer drug - Omeprazole)
SALES SPECIFICATION

APPEARANCE

 White to slightly beige powder
PURITY (Tit)

99.0% min

MELTING POINT

255 - 260 C

LOSS ON DRYING

0.5% max

ASH

0.5% max
TRANSPORTATION
PACKING 25kgs in bag
HAZARD CLASS  
UN NO.  
OTHER INFORMATION
European Hazard Symbols: XN, Risk Phrases: 22/37/45, Safety Phrases:26/36
Mercaptan: any of a class of organosulfur compounds is similar to the alcohol and phenol but containing a sulfur atom in place of the oxygen atom. Compounds containing -SH as the principal group directly attached to carbon are named 'thiols'. In substitutive nomenclature their names are formed by adding '-thiol' as a suffix to the name of the parent compound. When -SH is not the principal group, the prefix 'mercapto-' is placed before the name of the parent compound to denote an unsubstituted -SH group. 'thio'  is a chemical prefix indicates the replacement of an oxygen in an acid radical by sulfur with a negative valence of 2. Sulfur analog of alcohol is called thiol (or mercaptan), and ether analog is called sulfide.

The first chemical contrast of thiols and sulfides with alcohols and ethers is acidity which is important in organic reactions. Thiols are stronger acids than relevant alcohols and phenols. Thiolate conjugate bases are easily formed, and are excellent nucleophiles in SN2 reactions of alkyl halides and tosylates. The nucleophilicity of sulfur is much greater than that of oxygen, resulting in a number of useful electrophilic substitution reaction that are rare by oxygen. For example, sulfides form (with alkyl halides) ternary sulfonium salts, in the same alkylattion of tert-amines quaternary ammonium salts, whereas ternary oxonium salts are prepared only under extream conditions. Without exception, sulfoxides, sulfinate salts and sulfite anion also alkylate on sulfur, despite of the partial negative formal charge on oxygen and partial positive charge on sulfur. The second character is the oxidation states of sulfur. Oxygen has only two oxidation states, whereas sulfur covers from –2 to +6 as follows:

  • -2: Hydrogen Sulfide (H2S), sulfides, sulfonium ions
  • -1: disulfides
  • 0: S elemental, sulfoxides, sulfenic acids
  • +2: sulfones, sulfinic acids
  • +4: sulfonic acids, sulfite esters
  • +6: sulfate esters

One more sulfur compound's contrast with oxygen analog is in oxidation chemistry. Oxidation of sulfur compounds changes the oxidation state of sulfur rather than carbon, whereas, oxidation of  alcohols to aldehydes and ketones changes the oxidation state of carbon not oxygen. Thiols is oxidized to S-S single bond (disufide) which is stronger than O–O bond in peroxide. Disufide forms sulfenyl chlorides (with chlorine in mild condition) or sulfonic acids under harder condition. Oxidation of sulfides with hydrogen peroxide (or peracids) yields sulfoxides and then to sulfones. A certain sulfoxide compound such as dimethyl sulfoxide can be used as an effective oxygen source in the oxidation reaction of primary and secondary alcohols to aldehydes and ketones. DMSO easily is reduced to dimethyl sulfide and water is taken up by the electrophile. oxidation procedure is very mild and tolerates a variety of other functional groups, including those having oxidizable nitrogen and sulfur atoms.