Lawesson's Reagent (CAS 19172-47-5) Efficiently Converts Oxygen Functionalities into their Thio-Analogs16 May 2012 • by Natalie Aster
Lawesson's reagent (full name 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide (or -disulphide) is a chemical compound with the formula C14H14O2P2S4, used in organic synthesis as a thiation (also called thionation or sulfuration) agent. This light yellow to beige powder has a strong and unpleasant odour.
Lawesson's reagent was first produced in 1956 during a systematic study of the reactions of arenes with the comparable reagent P4S10. However it was Swedish chemist Sven-Olov Lawesson who popularized Lawesson's reagent within the chemical community.
Being commercially available, Lawesson's reagent can also be conveniently made in the laboratory by heating a mixture of anisole with phosphorus pentasulfide until the mixture is clear and no more hydrogen sulfide is formed, and then recrystallized from toluene or xylene.
The main application of Lawesson's reagent is the thionation of carbonyl compounds – the carbonyl group is converted into thiocarbonyl group, carbon-oxygen single bond is converted into a carbon-sulfur single bond, etc. In addition, Lawesson's reagent is used to thionate enones, esters, lactones, amides, lactams, and quinones.
The reaction of maltol with Lawesson's reagent was discovered to result in a selective oxygen replacement in two positions. Thiation reagent is also used to generate tropothione in situ at room temperature and trapping it with dieneophiles.
Lawesson's reagent market is covered in the study Lawesson's Reagent (CAS 19172-47-5) Market Research Report 2012. The report encompasses proper description of the product, unveils application areas, and briefly summarizes patents in the sphere. It overlooks Lawesson's reagent market situation, names manufacturers, suppliers as well as users. The report also provides current Lawesson's reagent prices in the market.
More information on the Lawesson's reagent market can be found in the report “Lawesson's Reagent (CAS 19172-47-5) Market Research Report 2012”.