Acetone → 2-Methyl-5-(pyrrolidin-1-yl)-pent-3-yn-2-ol

Temperature

-78 °C

A solution of 1-(pyrrolidin-1-yl)-prop-2-yne (prepared by the method of Biel and DiPierro J. Am. Chem. Soc. 1958, 80, 4609) (0.545 g) in dry tetrahydrofuran (15 ml) was treated at -78° C. with a solution of n-butyl lithium in hexanes (2.5 M, 2.2 ml) and the mixture was allowed to stir at -78° C. for 30 minutes and them permitted to warm to room temperature over the course of one hour. Upon recooling to -78° C. this mixture was treated with a solution of acetone (1 ml) in tetrahydrofuran (1 ml). The reaction was permitted to warm to room temperature over the course of two hours, and was then partitioned between ethyl acetate and water. The aqueous layer was extracted with ethyl acetate, and the pooled organic phase was washed with water, brine, and then dried over anhydrous sodium sulfate. The solvent was removed in vacuo to give a crude product, which was purified by column chromatography over silica gel (5% methanol in dichloromethane was used as the eluant) to afford the product as an oil. MS(+ES), m/z: 168 (M+H)+.

1. temperatureto warm to room temperature over the course of one hour
2. customUpon recooling to -78° C.
3. temperatureto warm to room temperature over the course of two hours
4. customwas then partitioned between ethyl acetate and water
5. extractionThe aqueous layer was extracted with ethyl acetate
6. washthe pooled organic phase was washed with water, brine
7. dry with materialdried over anhydrous sodium sulfate
8. customThe solvent was removed in vacuo
9. customto give a crude product, which
10. customwas purified by column chromatography over silica gel (5% methanol in dichloromethane

ORD record

ord-cf0d25827c4d4c0c9e41b6d0cab7dad0

Source dataset

uspto-grants-1999_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05932745