反应详情

A mixture of a 2.0 M solution of ethylamine in tetrahydrofuran (139.5 mL) and the hydrobromide salt of Example 12, Step A (9.5 g) was stirred at ambient temperature under nitrogen for 48 hours. The tetrahydrofuran was removed in vacuo and the residue was partitioned between dichloromethane and 1N sodium hydroxide. The extracts were washed with brine, dried over sodium sulfate, and concentrated in vacuo to give a brown oil. The crude material was dissolved in dichloromethane and absorbed onto a column of Merck-60 flash silica gel. Elution with a solvent gradient (from 95:5 to 80:20 dichloromethane-methanol containing 0.2% ammonium hydroxide) gave the title compound (3.4 g, 54.3%) as a yellow oil, which was used as such in the next step.

1. customThe tetrahydrofuran was removed in vacuo
2. customthe residue was partitioned between dichloromethane and 1N sodium hydroxide
3. washThe extracts were washed with brine
4. dry with materialdried over sodium sulfate
5. concentrationconcentrated in vacuo
6. customto give a brown oil
7. customabsorbed onto a column of Merck-60 flash silica gel
8. washElution with a solvent gradient (from 95:5 to 80:20 dichloromethane-methanol containing 0.2% ammonium hydroxide)