反应详情

A mixture of 1-benzyl-3R-methylpiperazine-2-one (XX, 4.36 g), lithium aluminum hydride (LAH, 2.33 g) and THF (125 ml) is heated at reflux for 16 hr. After cooling to 20°-25°, the mixture is quenched slowly with water (2.3 ml), sodium hydroxide (10%, 3.5 ml) and water (5.7 ml). The residue is diluted with ether (100 ml) and is stirred for 1 hr. The solids are filtered and washed successively with ether, methylene chloride and ether. The combined filtrates are dried over potassium carbonate, filtered and concentrated to give 1-benzyl-(3R)-methylpiperazine (XXI), sufficiently pure to be carried on crude, NMR (CDCl3) 7.2-7.4, 3.49, 2.7-3.0, 1.95-2.1, 166, 1.3-1.7 and 1.01 δ.

1. temperatureis heated
2. temperatureat reflux for 16 hr
3. temperatureAfter cooling to 20°-25°
4. customthe mixture is quenched slowly with water (2.3 ml), sodium hydroxide (10%, 3.5 ml) and water (5.7 ml)
5. additionThe residue is diluted with ether (100 ml)
6. filtrationThe solids are filtered
7. washwashed successively with ether, methylene chloride and ether
8. dry with materialThe combined filtrates are dried over potassium carbonate
9. filtrationfiltered
10. concentrationconcentrated