反应详情

To a suspension of N-methyl hydroxylamine hydrochloride (9.82 g, 117.6 mmol) in THF (150 mL) at room temperature there was added triethylamine (16.3 mL, 117.6 mmol) and the mixture stirred for 10 minutes. There was added, over 15 minutes, a solution of the isocyanate from Step 1 in THF (100 mL). After 2 hours of stirring at room temperature, the THF was evaporated and the residue, on trituration with water, afforded a yellow solid which was filtered. This solid was stirred in ether (150 mL) and filtered again. This crude material was chromatographed on silica gel eluting with 5% ethanol in methylene chloride. The more polar component of the mixture was stirred with methylene chloride (50 mL) for 2 hours and filtered and the solid crystallized from ethyl acetate to afford the pure title product as yellow crystals, mp 190-192° C. dec.

1. additionThere was added, over 15 minutes
2. stirringAfter 2 hours of stirring at room temperature
3. customthe THF was evaporated
4. customthe residue, on trituration with water, afforded a yellow solid which
5. filtrationwas filtered
6. stirringThis solid was stirred in ether (150 mL)
7. filtrationfiltered again
8. customThis crude material was chromatographed on silica gel eluting with 5% ethanol in methylene chloride
9. stirringThe more polar component of the mixture was stirred with methylene chloride (50 mL) for 2 hours
10. filtrationfiltered
11. customthe solid crystallized from ethyl acetate