1-(4-BroMothiophen-2-yl)-N,N-diMethylMethanaMine synthesis

Yield:78909-24-7 86%

Reaction Conditions:

with sodium cyanoborohydride;acetic acid in tetrahydrofuran;ethanol at 20;

Steps:

3.a

To a solution of 4-bromothiophene-2-carboxyaldehyde (5g, 26.3 mmol) in EtOH (130 mL) at rt and under N₂ was added the dimethylamine in THF (2OmL of a 2.0 M solution, 40 mmol) followed by AcOH (1.9 mL). NaBH₃CN (2.1 g, 34 mmol) was then added in portions to the reaction mixture over a 5 min period and the reaction mixture was stirred overnight at rt. The reaction mixture was diluted with saturated NaHCO₃ and extracted with CHCl₃ (3 x 50 mL). The combined organic layer was concentrated and the resulting residue was diluted with 1 N HCl and washed with CHCl₃. The acidic aqueous layer was then made basic with the addition of saturated NaHCO₃ and extracted with CHCl₃ (3 x 50 mL). The combined organic layer was washed with brine, dried (Na₂SO₄), filtered and concentrated (86 % yield). The product was used without further purification. ¹H NMR (500 MHz, CD₃OD) δ 2.26 (s, 6H), 3.65 (s, 2H), 6.92 (apparent s, IH), 7.31 (d, J= 2Hz, IH).

References:

WO2007/133155,2007,A1 Location in patent:Page/Page column 21