1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → (E)-3-(pyridin-4-yl)-1-(pyrrolidin-1-yl)prop-2-en-1-one

Participants

Reaction Steps

To a solution of 3-(4-pyridinyl)acrylic acid (1.01 g, 6.77 mmol) in CHCl3 (20 mL) in a 100 mL round bottom flask equipped with a magnetic stirrer and under nitrogen atmosphere was added 1-hydroxybenzotriazole (1.11 g, 8.21 mmol). The reaction mixture was stirred at RT for 10 min. Then 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (1.56 g, 8.15 mmol) was added. The reaction mixture was stirred at 4° C. for 10 min. Then pyrrolidine (1.11 mL, 18.3 mmol) was added slowly and the reaction mixture was stirred for 15 h at +4° C. to RT. Dichloromethane (200 mL) was added and organic phase was washed with brine (100 mL), a solution of NaOH 0.5 N (100 mL) and brine (50 mL). The organic phase was dried over MgSO4, filtered, and evaporated to obtain (E)-3-(pyridin-4-yl)-1-(pyrrolidin-1-yl)prop-2-en-1-one (1.30 g, 94% yield). This free base (1.3 g, 6.40 mmol) was dissolved in MeOH (10 mL) at 4° C. and a solution of HCl 0.1 N in isopropanol (79 mL, 7.9 mmol) was added. After evaporation at 30° C. and drying, (E)-3-(pyridin-4-yl)-1-(pyrrolidin-1-yl)prop-2-en-1-one hydrochloride Compound 253 was obtained as a beige solid (1.40 g, 87% yield).

Provenance & Evidence