methanedithiol
{{Chembox
| ImageFile = Methanedithiol.svg
| ImageSize = 120px
| ImageAlt =
| PIN = Methanedithiol
| OtherNames = Dimercaptomethane
|Section1={{Chembox Identifiers
| CASNo = 6725-64-0
| PubChem = 138818
| ChemSpiderID = 122421
| UNII = LSC543N4PH
| StdInChI=1S/CH4S2/c2-1-3/h2-3H,1H2
| StdInChIKey = INBDPOJZYZJUDA-UHFFFAOYSA-N
| SMILES = SCS
}}
|Section2={{Chembox Properties
| C=1|H=4|S=2
| MolarMass =
| Appearance = Colorless liquid
| Density =
| RefractIndex = 1.581
| MeltingPt =
| BoilingPtC = 58
| Solubility = }}
|Section3={{Chembox Hazards
| GHSPictograms = {{GHS02}}
| GHSSignalWord = Warning
| HPhrases = {{H-phrases|226}}
| PPhrases = {{P-phrases|210|233|240|241|242|243|280|303+361+353|370+378|403+235|501}}
| MainHazards =
| FlashPt =
| AutoignitionPt = }}
}}
Methanedithiol is an organosulfur compound with the formula H2C(SH)2. A seldom used chemical, it forms when formaldehyde reacts with hydrogen sulfide under pressure:
:{{chem2|CH2O + 2 H2S -> H2C(SH)2 + H2O}}
This reaction competes with formation of trithiane:
:{{chem2|3 H2C(SH)2 -> [H2CS]3 + 3 H2S}}
Methanedithiol forms a solid dibenzoate derivative upon treatment with benzoic anhydride:{{cite journal|title=gem-Dithiols|author1=Cairns, T. L. |author2=Evans, G. L. |author3=Larchar, A. W. |author4=McKusick, B. C. |journal=Journal of the American Chemical Society|year=1952|volume=74|issue=16|pages=3982–9|doi=10.1021/ja01136a004}}
:{{chem2|3 H2C(SH)2 + 2 (C6H5CO)2O -> H2C[SC(O)C6H5]2 + 2 C6H5CO2H}}
Methanetrithiol is also known.