Methyl iodide → 1-(2,3-Dihydro-benzo[1,4]dioxin-2-ylmethyl)-3-methyl-pyrrolidine-3-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution containing 80 mg (0.29 mmol) of 1-(2,3-dihydro-benzo[1,4]dioxin-2-ylmethyl)-pyrrolidine-3-carboxylic acid methyl ester in dry tetrahydrofuran (4.5 mL) at −78° C. under nitrogen was added 0.3 mL (0.58 mmol) of lithium diisopropylamine (2.0 M solution in heptane/tetrahydrofuran/ethylbenzene). The reaction mixture was stirred at −78° C. for 1 h and subsequently 0.04 mL (0.58 mmol) of iodomethane was added. The reaction mixture was allowed to warm to room temperature and the stirring was continued for 3 h. The reaction was quenched with 15 mL of saturated aqueous NH4Cl-solution and the tetrahydrofuran was evaporated off under vacuum. Water (50 mL) was added and the pH was adjusted to 10 using 1M Na2CO3. The water phase was extracted with ethyl acetate (3×25 mL), and the combined organic phases were dried over anhydrous sodium sulfate, filtered, and evaporated to dryness, and the residue was dried under high vacuum.

Provenance & Evidence