Trifluoroacetic acid → 2,2-dimethyl-4-oxo-4H-1,3-benzodioxine-6-carbonitrile

反応式

[C:1]([C:3]1[CH:11]=[C:7]([C:8]([OH:10])=[O:9])[C:6]([OH:12])=[CH:5][CH:4]=1)#[N:2].[C:13](O)([C:15](F)(F)F)=O.[C:20](OC(C(F)(F)F)=O)(C(F)(F)F)=O>CC(C)=O>[CH3:20][C:13]1([CH3:15])[O:12][C:6]2[CH:5]=[CH:4][C:3]([C:1]#[N:2])=[CH:11][C:7]=2[C:8](=[O:10])[O:9]1

参加物

実験手順

To a suspension of 5-cyano salicylic acid (60 g, 0.368 mol) in TFA (134 mL, 1.76 mol) and TFAA (45 mL, 0.32 mol) was added dry acetone (20 mL) and heated to reflux. After each 1 h interval was added 15 mL of dry acetone for 4 times and the reflux continued for 20 h. The reaction mixture was concentrated under vacuum and crude purified by flash column chromatography over silica gel (230-400 mesh) using CH2Cl2 as an eluent to give the title compound as a white solid (12 g, 15%). TLC: CH2Cl2 (100%), Rf: 0.5