4-Bromo-2-propionylthiophene synthesis

Yield:36155-78-9 100%

Reaction Conditions:

with bromine;Aluminum Chloride in chloroform at 20; for 17 h;

Steps:

112.a

EXAMPLE 112; Preparation of 2-Amino-5-(3bromophenyl)-5-[5-(2-ethyl-[1,3]dioxolan-2-yl)-thiophen-3-yl]-3-methyl-3,5-dihydro-imidazol-4-one; Step a); A stirred suspension of aluminum trichloride (6.27 g, 47.1 mmol) in chloroform at room temperature was treated sequentially with 2-(1-propionyl)thiophene (3.00 g, 21.4 mmol) and bromine (3.60 g, 22.4 mmol), stirred for 17 h, poured into iced water and diluted with methylene chloride. The phases were separated and the aqueous phase was extracted with methylene chloride. The extracts and the organic phase were combined, washed with water and brine, dried over sodium sulfate and concentrated to afford 2 (5.51 g, 117%) as a dark orange oil: ¹H NMR (300 MHz, CDCl₃) δ 7.59 (d, J=1.1 Hz, 1H), 7.51 (d, J=1.1 Hz, 1H), 2.91 (q, J=7.3 Hz, 2H), 1.23 (t, J=7.3 Hz, 3H); ESI MS m/z 219 [C₇H₇BrOS+H]⁺.

References:

US2007/4786,2007,A1 Location in patent:Page/Page column 39-40