6-(3-THIENYL)HEXANOIC ACID synthesis

Yield:377089-95-7 88%

Reaction Conditions:

with N-Bromosuccinimide in N,N-dimethyl-formamide at 0; for 48 h;absence of light;

Steps:

1

EXAMPLES; Example 1; [0077] Synthesis of 2,5-dibromo-6-(thien-3-yl)hexanoic acid (2); [0078] A solution of 2.92 g (16.4 mmol) of NBS in DMF (50 ml) is slowly added dropwise at 0[deg.] C. to a solution of 6-(thien-3-yl)hexanoic acid 1 (1.63 g, 8.20 mmol) in DMF (50 ml) with exclusion of light. The solution is stirred for 48 hours and then poured onto ice. The mixture is extracted a number of times with dichloromethane. The organic phases are combined, washed with water and dried over sodium sulfate. After removal of the solvent, the crude product is chromatographed on silica gel using n-hexane/ethyl acetate (1:1) as eluent (flash chromatography). This gives 2.57 g of 2 (88%) as an orange viscous oil; C10H12O2SBr2 Calc.: C, 33.73; H, 3.40. found: C, 33.56; H, 3.40. <1>H-NMR (200 MHz, CDCl3): [delta]H=6.77 (s, 1 H, 4'-H), 2.52 (t, <3>J=7.9 Hz, 2 H, 6-H ), 2.37 (t, <3>J=7.9 Hz, 2 H, 2-H), 1.75-1.51 (m, 4 H, 3-H, 5-H), 1.45-1.33 (m, 2 H, 4-H); <13>C-NMR (126 MHz, CDCl3): [delta]C 179.3 (C-1), 142.5, 131.0, 110.5, 108.1 (C-2'-C-5'), 33.8, 29.2 (2 C), 28.4, 24.3 (C-2-C-6).

References:

US2003/195330,2003,A1 Location in patent:Page/Page column 2; 5