反应详情

2-Bromo-3-methoxythiophene-4-carboxylic acid (0.429 g; 1.81 mmol) was heated at reflux in thionyl chloride (8 ml) for 1 hour, cooled, evaporated in vacuo and the residue azeotroped with toluene. The orange residue was redissolved in CH2Cl2 (5 ml) and treated with dry triethylamine (0.25 ml;1.81 mmol) and 4-methoxy-3-(4-methyl-1-piperazinyl)benzenamine (0.4 g; 1.8mmol). The solution was stirred under Ar (18 hours), evaporated in vacuo and partitioned satd. K2CO3 (aq)/EtOAc. The organic phases were combined, dried over Na2SO4, filtered and the filtrate evaporated in vacuo to a brown gum. The gum was purified by flash silica-gel chromatography and eluted with 2%MeOH/CHCl3 to yield the title compound as white powder after trituration with Et2O (0.43 g;54%), mp=120-122° C.

1. temperaturecooled
2. customevaporated in vacuo
3. customthe residue azeotroped with toluene
4. dissolutionThe orange residue was redissolved in CH2Cl2 (5 ml)
5. customevaporated in vacuo
6. custompartitioned
7. dry with materialdried over Na2SO4
8. filtrationfiltered
9. customthe filtrate evaporated in vacuo to a brown gum
10. customThe gum was purified by flash silica-gel chromatography
11. washeluted with 2%MeOH/CHCl3