3,4-dihydro-2H-pyran → N-[[4-[2-(5-hydroxypentylidene)hydrazinyl]phenyl]methyl]methanesulfonamide

To a solution of 23.9 g of crude N-[(4-hydrazinylphenyl)methyl]methanesulfonamide hydrochloride in 175 mL of water and 300 mL of ethanol was added sufficient sodium acetate to bring the pH to 4. To the resulting suspension was added 10.4 mL (114 mmol, 1.3 equiv.) of 3,4- dihydro-2H-pyran. The mixture was then stirred for twenty hours at room temperature. The ethanol was removed in vacuo. The pH was raised to 10 by adding solid potassium carbonate and the mixture was extracted three times with 50 mL portions of methylene chloride. The combined organic layers were washed with 25 mL of saturated aqueous sodium chloride, dried over magnesium sulfate and filtered to give an oil. The oil was purified by chromatography on silica gel using 5% methanol in methylene chloride containing 0.5% concentrated aqueous ammonium hydroxide to yield 11.1 g (39%, two steps) of pure N-[[4-[2-(5-hydroxypentylidene)hydrazinyl]phenyl]methyl]methanesulfonamide.

1. customThe ethanol was removed in vacuo
2. temperatureThe pH was raised to 10
3. additionby adding solid potassium carbonate
4. extractionthe mixture was extracted three times with 50 mL portions of methylene chloride
5. washThe combined organic layers were washed with 25 mL of saturated aqueous sodium chloride
6. dry with materialdried over magnesium sulfate
7. filtrationfiltered
8. customto give an oil
9. customThe oil was purified by chromatography on silica gel using 5% methanol in methylene chloride containing 0.5% concentrated aqueous ammonium hydroxide

ORD 기록

ord-9e3df00f22914833aeca13119a0c4545

출처 데이터셋

uspto-grants-1994_04

DOI

10.6084/m9.figshare.5104873.v1

특허 번호

US05300506