Phosphorus sulfide (P2S5) → 2H-Pyran-2-thione, 4,6-diphenyl-
Reaction equation
[C:1]1([C:7]2[CH:12]=[C:11]([C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=3)[O:10][C:9](=O)[CH:8]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.P12(SP3(SP(SP(S3)(S1)=S)(=S)S2)=S)=[S:21]>C1C=CC=CC=1>[C:1]1([C:7]2[CH:12]=[C:11]([C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=3)[O:10][C:9](=[S:21])[CH:8]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
Under an inert atmosphere, 2.1 g of the product of Step A 45 ml of benzene and 7.5 g of phosphorus pentasulfide were mixed together and refluxed under inert atmosphere for 5 hours. Then the supernatant solution was decanted hot and concentrated to dryness by distilling under reduced pressure. This operation was repeated hot on the reaction medium four times, each time with 30 ml of benzene. The concentrates were put together and dried under a good vacuum to obtain 3 g of product which was chromatographed on silica and eluted with methylene chloride to obtain 2 g of the product sought melting at 122°-123° C.