bromobenzarone synthesis

Yield: 57%

Reaction Conditions:

with sodium thioethylate in N,N-dimethyl-formamide at 105 - 110; for 16 h;

Steps:

In a RBF/SB, 56 (0.05 g, 0.139 mmol) was weighed out. The material was diluted with DMF (2.5 mL), NaSEt (0.058 g, 0.696 mmol) was added and warmed (105-1 10 °C; 16 h). The mixture was then quenched with 2 vol NH₄C1 aq and extracted with EtOAc (4 x 20 mL). The organic phase was dried (Na₂S0₄), filtered, concentrated under reduced pressure and purified via Si0₂ chromatography (3: 1 ; Hex: EtOAc) to give 61 (23.2 mg, 0.079 mmol, 57% yield) as a light yellow oil. 1H-NMR (400 MHz) CDC1₃: 8.06-8.05 (d, 1H), 7.76-7.74 (dd, 1H), 7.50- 7.48 (d, 1H), 7.41-7.39 (d, 1H), 7.31-7.29 (t, 1H), 7.23-7.19 (t, 1H), 7.10-7.08 (d, 1H), 6.21 (bs, 1H), 2.94-2.89 (q, 2H), 1.37-1.33 (t, 3H); ¹³C-NMR (100 MHz) CDC1₃: 189.2, 166.0, 156.3, 153.7, 133.8, 133.2, 131.1 , 126.8, 124.5, 123.6, 121.1 , 1 15.9, 1 15.8, 1 1 1.1 , 1 10.5, 21.8, 12.3. LC/MS-MS: 344.9 -» 198.8 m/z GS1 and GS2 at 25, DP = 61, CE = 33, CXP = 12, t_R = 4.59 min.

References:

J-PHARMA CO., LTD.;WEMPE, Michael, F.;ENDOU, Hitoshi WO2012/48058, 2012, A2 Location in patent:Page/Page column 33-34