Lawesson's reagent

• 2,4- bis (4 -methoxyphenyl) -1,3,2,4 - dithiadiphosphetan -2 ,4-disulfide
• LR

Yellow, foul-smelling powder

Fixed

221-224 ° C

Decomposition in water

Risk

Template: Infobox chemical / molecular formula search available

Lawesson's reagent is a phosphorus-and sulfur -containing organic compound and was named after its discoverer, the Swedish chemist Sven- Olov Lawesson, named.

Production

Lawesson's reagent is synthesized from phosphorus (V ) sulfide, and anisole.

Use

Lawesson's reagent has proven to be extremely useful for the preparation of thiocarbonyl compounds from carbonyl compounds. It is more reactive than phosphorus (V ) sulphide, P4S10, and sufficiently soluble in organic solvents at a higher temperature so that the reactions can be carried out in a homogeneous solution. Lactams using Lawesson's reagent can be converted into Thiolactams:

Mechanism

The reagent is in equilibrium with the monomeric form. It reacts in a mechanism similar to the Wittig reaction with a carbonyl compound.