Triethylamine → Benzyl 3-hydroxypyrrolidine-1-carboxylate

Temperature

0 °C

A solution of 35.6 ml of benzylchloroformate in 200 ml of dichloromethane was added dropwise to a mixture of 10 g of (racemic)-3-pyrrolidinol, 48.3 ml of triethylamine and 725 ml of dichloromethane which was cooled to 0° C. The mixture was stirred for 48 hours at room temperature. The dichloromethane solution was extracted with 5% hydrochloric acid and 5% aqueous sodium bicarbonate. The acid and bicarbonate washes were combined, salted with sodium chloride and extracted with 2×750 ml of ethyl acetate. The combined organic extracts were dried and concentrated, giving 22.7 g of (racemic)-N-carbobenzyloxy-3-pyrrolidinol. A mixture of 2.5 g of (racemic)-N-carbobenzyloxy-3-pyrrolidinol, 2.0 ml of methyl iodide and 5.1 g of silver oxide in 50 ml of dimethylformamide was stirred at room temperature for 2 days. The mixture was diluted with ether and then filtered. The filtrate was concentrated to a small volume. The ether solution was washed with water, dried and concentrated to dryness in vacuo. The residue was purified by chromatography (silica gel) to give 2.4 g of (racemic)-N-carbobenzyloxy-3-methoxypyrrolidine as a pale yellow oil.

1. extractionThe dichloromethane solution was extracted with 5% hydrochloric acid and 5% aqueous sodium bicarbonate
2. extractionextracted with 2×750 ml of ethyl acetate
3. customThe combined organic extracts were dried
4. concentrationconcentrated

ORD record

ord-6922a17665c14fb59a306f335bf78b2b

Source dataset

uspto-grants-1990_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04937235