Lawesson's reagent → N-(2-cyanoethyl)-2,2-bis(fluoromethyl)-6-nitro-2H-1-benzopyran-4-carbothioamide
Reaction equation
[C:1]([CH2:3][CH2:4][NH:5][C:6]([C:8]1[C:13]2[CH:14]=[C:15]([N+:18]([O-:20])=[O:19])[CH:16]=[CH:17][C:12]=2[O:11][C:10]([CH2:23][F:24])([CH2:21][F:22])[CH:9]=1)=O)#[N:2].COC1C=CC(P2(SP(C3C=CC(OC)=CC=3)(=S)S2)=[S:34])=CC=1>C1C=CC=CC=1>[C:1]([CH2:3][CH2:4][NH:5][C:6]([C:8]1[C:13]2[CH:14]=[C:15]([N+:18]([O-:20])=[O:19])[CH:16]=[CH:17][C:12]=2[O:11][C:10]([CH2:23][F:24])([CH2:21][F:22])[CH:9]=1)=[S:34])#[N:2]Participants
4
Procedure
A mixture of 0.11 g of N-(2-cyanoethyl)-2,2-bis(fluoromethyl)-6-nitro-2H-1-benzopyran-4-carboxamide and 0.17 g of a Lawesson's reagent and 10 ml of benzene was refluxed with heating for 2 hours. The solvent was distilled and the obtained residue was purified according to silica gel column chromatography (developing solution, MeOH:CH2Cl2 =1:99) and further recrystallyzed by a mixed solvent of ethyl acetate and hexane to obtain 42 mg of N-(2-cyanoethyl)-2,2-bis(fluoromethyl)-6-nitro-2H-1-benzopyran-4-carbothioamide with a melting point of 114°-116° C.