反应详情

To a solution of 6.6 g (0.03 mole) of 1-piperazinecarboxylic acid, phenylmethyl ester in 100 ml of N,N-dimethylformamide was added, in portions, 1.44 g (0.03 mole) of a 50% sodium hydride suspension in mineral oil. The mixture was heated at 50° for 1 hr and allowed to cool slightly. To it was added dropwise a solution of 8.8 g (0.003 mole) of 2-(ethylsulfonyl)ethanol, 4-methylbenzenesulfonate in 30 ml of N,N-dimethylformamide. The mixture was heated at 50° for 1 hr, allowed to cool, concentrated under vacuum to one-half the original volume, allowed to stand for four days and then concentrated to a paste. The paste was diluted with ether and the suspension filtered to remove insoluble salts. The filtrate was concentrated and chromatographed over 250 g of silica gel with 1 l each of the following solutions of methanol in ethyl acetate: 1.5%, 3% and 15%. That portion of the eluent containing the product, Rf(silica--10 % methanol/ethyl acetate)=0.7, was concentrated to dryness under vacuum to afford 8.3 g (81%) of the desired product as an oil. The IR and NMR spectra were consistent with the assigned structure.

1. temperatureThe mixture was heated at 50° for 1 hr
2. temperatureto cool slightly
3. temperatureThe mixture was heated at 50° for 1 hr
4. temperatureto cool
5. concentrationconcentrated under vacuum to one-half the original volume
6. concentrationconcentrated to a paste
7. additionThe paste was diluted with ether
8. filtrationthe suspension filtered
9. customto remove insoluble salts
10. concentrationThe filtrate was concentrated
11. customchromatographed over 250 g of silica gel with 1 l each of the following solutions of methanol in ethyl acetate
12. additionThat portion of the eluent containing the product, Rf(silica--10 % methanol/ethyl acetate)=0.7
13. concentrationwas concentrated to dryness under vacuum