Benzyl mercaptan

Benzyl mercaptan
CAS number 100-53-8 YesY
PubChem 7509
ChemSpider 13851383 YesY
Jmol-3D images Image 1
Molecular formula C7H8S
Molar mass 124.20 g/mol
Appearance colourless liquid
Odor leek or garlic-like
Density 1.058 g/mL
Melting point

-30 °C, 243 K, -22 °F

Boiling point

195 °C, 468 K, 383 °F

Solubility in water low
Solubility very soluble in ethanol, ether
soluble in CS2
slightly soluble in CCl4
Refractive index (nD) 1.5751 (20 °C)
NFPA 704
Flash point 70 °C (158 °F)
LD50 493 mg/kg (rat, oral)
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
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 a nucleophile like 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

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 taking advantage of the weakened S-benzyl bond:[2]

RSCH2C6H5 + 2 "H" → RSH + CH3C6H5

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