F[C:2]1[CH:8]=[C:7]([C:9]#[C:10][Si](C)(C)C)[CH:6]=[CH:5][C:3]=1[NH2:4].[C:15]([S-:20])(=[S:19])OCC.[K+].O.Cl>CN(C=O)C>[C:9]([C:7]1[CH:6]=[CH:5][C:3]2[N:4]=[C:15]([SH:20])[S:19][C:2]=2[CH:8]=1)#[CH:10]
To a solution of 2-fluoro-4-((trimethylsilyl)ethynyl)aniline (4.4 g, 21.2 mmol) from Step 1 of this Example in 20 mL of DMF was added potassium O-ethyl carbonodithioate (7.48 g, 46.8 mmol). The resulting mixture was heated under reflux for 4 h. After cooling to rt, the reaction mixture was treated with water (30 mL) and 1N HCl (100 mL). The mixture was stirred at rt for 2 h before the precipitates were collected by filtration and washed with water to give the crude 6-ethynylbenzo[d]thiazole-2-thiol (4.0 g, 99%) as a dark brown solid. LCMS (ESI) m/z 192 (M+H)+.
Wird geladen…
