反应详情

A solution of ethyl 2-mercaptoacetate (18.4 ml) in DMF (650 ml) was ice-cooled and treated with sodium hydride (6.78 g of a 60% dispersion in oil). After 1 hour methyl 6-amino-3,5-dibromopyridine-2-carboxylate (50 g) (T. R. Kelly and F. Lang, J. Org. Chem. 61, 1996, 4623-4633) was added and the mixture stirred for 16 hours at room temperature. The solution was partitioned between EtOAc and water (2 liters each), shaken, separated and the EtOAc along with solid that crystallised out washed with water (2×1 liter). The EtOAc was evaporated to low volume, solid filtered, washed with water and EtOAc and dried. The filtrate was separated, EtOAc dried and evaporated. The residue was taken up in AcOH and heated to 100° C. overnight, then evaporated. The white solid was triturated uder EtOAc, filtered off, washed with a little EtOAc and dried (Na2SO4). Combining the 2 batches of ester gave 33.35 g (70%). MS (APCl−) m/z 223 ([M−H]−, 100%).

1. temperaturecooled
2. addition61, 1996, 4623-4633) was added
3. customThe solution was partitioned between EtOAc and water (2 liters each)
4. stirringshaken
5. customseparated
6. customthe EtOAc along with solid that crystallised
7. washout washed with water (2×1 liter)
8. customThe EtOAc was evaporated to low volume, solid
9. filtrationfiltered
10. washwashed with water and EtOAc
11. customdried
12. customThe filtrate was separated
13. dry with materialEtOAc dried
14. customevaporated
15. temperatureheated to 100° C. overnight
16. customevaporated
17. customThe white solid was triturated uder EtOAc
18. filtrationfiltered off
19. washwashed with a little EtOAc
20. dry with materialdried (Na2SO4)
21. customgave 33.35 g (70%)