反应详情

A solution of (+/−)-2-(tert-butoxycarbonylamino)-6-methyl-4-(3-nitropyridin-4-yl)cyclohex-3-enyl methanesulfonate (1.0 equiv.) in pyridine (0.2 M) in a microwave vessel was heated to 110° C. for 10 min. The orange solution was then concentrated to dryness and worked up by partitioning between ethyl acetate and water. The organic phase was dried with sodium sulfate, filtered and concentrated. The crude material was dissolved in DCM (0.2 M) and triethyl amine (1.8 equiv.) was added to the reaction, followed by Boc2O (1.2 eqiv.). After stirring at room temperature for 40 min, the reaction was concentrated in vacuo and purified via silica gel column chromatography eluting with ethyl acetate and hexanes (1:1) to give (+/−)-tert-butyl 7-methyl-5-(3-nitropyridin-4-yl)-2-oxo-3a,6,7,7a-tetrahydrobenzo[d]oxazole-3(2H)-carboxylate as a white foam in 66% yield. LC/MS=376.0 (M+H), Rt=0.87 min.

1. concentrationThe orange solution was then concentrated to dryness
2. customby partitioning between ethyl acetate and water
3. dry with materialThe organic phase was dried with sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated
6. dissolutionThe crude material was dissolved in DCM (0.2 M)
7. concentrationthe reaction was concentrated in vacuo
8. custompurified via silica gel column chromatography
9. washeluting with ethyl acetate and hexanes (1:1)