Benzyl mercaptan

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Benzyl mercaptan
Skeletal formula benzyl mercaptan
Ball-and-stick model of the benzyl mercaptan molecule
Names
Preferred IUPAC name
Phenylmethanethiol
Other names
alpha-Toluenethiol
Benzylthiol
Thiobenzyl alcohol
Benzyl mercaptan
alpha-Toluolthiol
Benzylhydrosulfide
Benzyl hydrosulfide
Identifiers
100-53-8 YesY
ChEMBL ChEMBL1224557 YesY
ChemSpider 13851383 YesY
Jmol 3D model Interactive image
PubChem 7509
UNII OS34A21OBZ N
Properties
C7H8S
Molar mass 124.20 g/mol
Appearance colourless liquid
Odor leek or garlic-like
Density 1.058 g/mL
Melting point −30 °C (−22 °F; 243 K)
Boiling point 195 °C (383 °F; 468 K)
low
Solubility very soluble in ethanol, ether
soluble in CS2
slightly soluble in CCl4
1.5751 (20 °C)
Hazards
NFPA 704
Flammability code 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g., diesel fuel Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point 70 °C (158 °F; 343 K)
Lethal dose or concentration (LD, LC):
493 mg/kg (rat, oral)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YesYN ?)
Infobox references

Benzyl mercaptan is an organosulfur compound with the formula C6H5CH2SH. It is a common laboratory alkylthiol and occurs in trace amounts naturally. Condensed tannins can undergo acid-catalyzed cleavage in the presence of the nucleophilic benzyl mercaptan. Benzyl mercaptan has been identified in boxwood (Buxus sempervirens L.) and is known to contribute to the smoky aroma of certain wines.[1] It also occurs naturally in coffee.

It is created by the reaction of benzyl chloride and sodium hydrosulfide.

Use in organic synthesis[edit]

The compound is used as a source of the thiol functional group in organic synthesis. It is introduced by S-alkylation to give alkyl benzylthioethers. Debenzylation is effected by dissolving metal reduction, which attacks the weakened S-benzyl bond:[2]

RSCH2C6H5 + 2 "H" → RSH + CH3C6H5

Methoxy-substituted derivatives of benzyl mercaptan have been developed that cleave easily, are recyclable, and are odourless.[3]

References[edit]

  1. ^ Contribution of benzenemethanethiol to smoky aroma of certain Vitis vinifera L. wines. Tominaga, Takatoshi; Guimbertau, Guy; Dubourdieu, Denis, 2003
  2. ^ Norman Kharasch and Robert B. Langford (1973). "2,4-dinitro-Benzenesulfenyl chloride". Org. Synth. ; Coll. Vol., 5, p. 474 
  3. ^ M. Matoba, T. Kajimoto, M. Node "Development of a Novel Benzyl Mercaptan as a Recyclable Odorless Substitute of Hydrogen Sulfide" Synlett 2007, pp. 1930-4. doi:10.1055/s-2007-984524