反应详情

A mixture of 13.8 g of ethyl 1-aminopyridinium 3-carboxylate 2,4,6-trimethylbenzenesulphonate (compound A) (Synthesis 1977, page 1, TAMURA, et al.), 150 ml of dimethylformamide, 5.7 g of potassium carbonate and 10 g of the product of Step A of Example 1 were stirred for 3 hours at room temperature and then 6.9 g of compound A and 2.85 g of potassium carbonate were added. The mixture was stirred for 2 hours. Then 6.9 g of compound A and 2.85 g of potassium carbonate were added and the mixture was stirred for 2 hours at ambient temperature. The mixture was taken up in water and extracted with ethyl acetate. Separation was carried out by chromatography on silica (essence G: 80/ethyl acetate: 20) to obtain 7.38 g of the expected product (M.p.≤50° C.) and 8.25 g of the corresponding isomer of Example 16.

1. stirringThe mixture was stirred for 2 hours
2. stirringthe mixture was stirred for 2 hours at ambient temperature
3. extractionextracted with ethyl acetate
4. customSeparation