反应详情

A solution of 1-[2-bromoethyl]cyclopentanecarboxylic acid methyl ester (49.6 g, 211 mmol) and sodium azide (54 g, 831 mmol) in DMF (200 mL) was stirred at 50° C. for 5 h under nitrogen atmosphere. Then, the solids were filtered and the filtrate was concentrated to near dryness. The residue was diluted with ethyl acetate (500 mL) and the undissolved solids were collected by filtration and the filtrate was concentrated to give the crude ethyl 1-(2-azidoethyl) cyclopentanecarboxylate which was purified by chromatography over 250 g of silica gel, eluting with 5% ethyl acetate in hexane to give 36.2 g (87% yield) of 1-[2-azidoethyl]cyclopentanecarboxylic acid methyl ester as a light brown oil. EI(+)-HRMS m/e calcd. for C9H15N3O2 (M−H)+ 196.1086, obsd. 196.1342.

1. filtrationThen, the solids were filtered
2. concentrationthe filtrate was concentrated
3. additionThe residue was diluted with ethyl acetate (500 mL)
4. filtrationthe undissolved solids were collected by filtration
5. concentrationthe filtrate was concentrated
6. customto give the crude ethyl 1-(2-azidoethyl) cyclopentanecarboxylate which
7. customwas purified by chromatography over 250 g of silica gel
8. washeluting with 5% ethyl acetate in hexane