Hydrochloric Acid → HCID 59315613, compound

Participants

Reaction Conditions

Reaction Steps

Sodium hydride (977 mmol, 23.45 g) was suspended in tetrahydrofuran (700 mL) and cooled to 5° C. with an ice-water bath. To this cold suspension was added 1-vinyl-pyrrolidin-2-one (465 mmol, 51.7 g) over approximately 20 minutes, maintaining an internal temperature reaction temp of less than 5° C. then ethyl 2-bromobenzoate (437 mmol, 100 g) was added. After the addition was complete the reaction was stirred at 5° C. for 10 minutes then refluxed for 2 hours and allowed to cool to room temperature. To the suspension was added 5N HCl (600 mL) dropwise, maintaining reaction temperature between 25° C. and 35° C. The bulk of the tetrahydrofuran was then distilled off at a temperature of 60° C. under vacuum. The resulting solution was cooled and further 5N hydrochloric acid (600 mL) was added and the mixture was refluxed overnight. The solution was then cooled with a salt-ice bath to 5° C. and basified by the careful addition of sodium hydroxide pellets (˜250 g) maintaining an internal temperature between 10 and 15° C. When reaction mixture was at pH 13, the cooling bath was removed and temperature allowed to reach room temperature. The reaction was then extracted with methylene chloride (1 L) and the aqueous layer was extracted with further methylene chloride (2×1 L). The combined methylene chloride extracts were dried with sodium sulfate, filtered and evaporated to dryness to give 5-(2-bromophenyl)-3,4-dihydro-2H-pyrrole (92.2 g).

Provenance & Evidence