2-Butenoicacid,4-(dimethylamino)-,(E)-(9CI) synthesis

Yield:149586-32-3 54%

Reaction Conditions:

Stage #1:4-dimethylaminocrotonic acid methyl ester hydrochloride with water;sodium hydroxide in methanol at 45; for 0.5 h;
Stage #2: with hydrogenchloride in isopropyl alcohol; pH=2

Steps:

4.2
1 g of the compound obtained in step 1) above was dissolved in 6.6 mL of methanol, and 2.2 mL of an aqueous solution of 40% sodium hydroxide added thereto. The mixture was heated to 45 °C and stirred for 30 min. Then the mixture was acidified (pH 2) with 10% hydrochloric acid solution in 2-propanol and filtered under a reduced pressure. The filtrate was distilled under a reduced pressure, dissolved in 3 mL of 2-propanol, and heated to 35°C, followed by stirring for 10 min. Subsequently, 3 mL of acetone was added thereto, stirred at 40°C for 30 min, and stirred again at room temperature for 12 hours. The resulting solid was filtered under a reduced pressure and washed with a mixed solvent of 2-propanol and acetone (1 : 2), followed by drying under a reduced pressure to obtain the title compound (500 mg, yield: 54%).1H-NMR (300MHz, DMSO-d₆) δ 6.85 (m, 1H), 6.18 (m, 1H), 3.87 (d, 2H), 2.69 {s, 6H).

References:

HANMI HOLDINGS CO., LTD.;CHA, Mi Young;KIM, Mi Ra;KANG, Seok Jong;KIM, Se Young;JUNG, Young Hee;LEE, Kwang Ok;SONG, Ji Yeon;KIM, Young Hoon;KIM, Eun Young;KIM, Maeng Sup WO2011/99764, 2011, A2 Location in patent:Page/Page column 22

FullText