2-Thiazolecarboxylic acid, 4-(5-broMo-1H-pyrrolo[2,3-b]pyridin-3-yl)-, ethyl ester synthesis

Yield:1046793-71-8 90%

Reaction Conditions:

in 1,4-dioxane at 95; for 18 h;

Steps:

4-(5-Bromo-1H-pyrrolo[2,3-b]pyridin-3-yl)-thiazole-2-carboxylic acid ethyl ester (78)

4-(5-Bromo-1H-pyrrolo[2,3-b]pyridin-3-yl)-thiazole-2-carboxylic acid ethyl ester (78) To a stirred solution of 70 (4.97 g, 15.6 mmol) in dioxane (55 mL) was added ethyl thiooxamate (2.29 g, 17.2 mmol). The reaction mixture was stirred vigorously at 95° C. for 18 h. The hot reaction mixture was filtered and the collected product was washed with cold dioxane (25 mL) to afford the hydrobromide salt of 78 as a yellow powder (6.08 g, 14.0 mmol, 90%). ¹H NMR (400 MHz, CDCl₃) δ 1.48 (t, J=7.1 Hz, 3H), 4.52 (q, J=7.1 Hz, 2H), 7.77 (s, 1H), 8.05 (s, 1H), 8.43 (d, J=1.8 Hz, 1H), 9.21 (s, 1H).

References:

US2007/72896,2007,A1 Location in patent:Page/Page column 70