反应详情

温度

-15 °C

S-Methyl-N-acetyl-L-cysteine (3.54 g, 20 mmole) was dissolved in 25 ml of tetrahydrofuran and 2.8 ml (20 mmole) of triethylamine was added thereto. Upon cooling to -15° C., 2.7 ml (20 mmole) of butyl chloroformate was added dropwise and the mixture was stirred for 20 minutes at that temperature. After cooling to -40° C., 3.0 ml (46.6 mmole) of aqueous 70% ethylamine solution was added in one portion and stirred for 3 hours under ice cooling. The reaction mixture was extracted with 100 ml of ethyl acetate three times and the extracts were washed successively with 2×30 ml of aqueous 5% sodium bicarbonate and 2×30 ml of saturated saline, dried over anhydrous magnesium sulfate and then concentrated in vacuo. The resulting crystals were collected and washed with ethyl ether to give 2.20 g (53.8% yield) of S-methyl-N-acetyl-L-cysteine ethylamide.

1. temperatureAfter cooling to -40° C.
2. stirringstirred for 3 hours under ice cooling
3. extractionThe reaction mixture was extracted with 100 ml of ethyl acetate three times
4. washthe extracts were washed successively with 2×30 ml of aqueous 5% sodium bicarbonate and 2×30 ml of saturated saline
5. dry with materialdried over anhydrous magnesium sulfate
6. concentrationconcentrated in vacuo
7. customThe resulting crystals were collected
8. washwashed with ethyl ether