Imidazole → tert-butyl 4-{2-[(1S)-1-hydroxypropyl]-4,5-dimethylphenyl}-3,6-dihydropyridine-1(2H)-carboxylate

Diisopropylazidocarboxylate (2.96 mL, 15.1 mmol) was added dropwise to a stirred mixture of alcohol 109 (1.3 g, 3.76 mmol), Zn(N3)2.2Py (prepared according to the method described by Viaud, M-C; Rollin, P. in Synthesis, 1990,130), triphenylphosphine (3.95 g, 15.1 mmol) and imidazole (1.03 g, 15.1 mmol) in DCM (100 mL) at approximately 0° C. After the addition, the resulting mixture was allowed to warm to ambient temperature and stirred vigorously for 18 h. The reaction mixture was filtered through a short column of silica gel eluted with the appropriate volume of DCM to remove excess salts and polar byproducts. The filtrate was concentrated in vacuo and the crude residue purified by flash chromatography on silica gel (gradient elution; 0%-20% EtOAc/hexanes as eluent) to afford azide 110 as a colorless oil.

1. custom2Py (prepared
2. additionAfter the addition
3. filtrationThe reaction mixture was filtered through a short column of silica gel
4. washeluted with the appropriate volume of DCM
5. customto remove excess salts and polar byproducts
6. concentrationThe filtrate was concentrated in vacuo
7. customthe crude residue purified by flash chromatography on silica gel (gradient elution; 0%-20% EtOAc/hexanes as eluent)

ORD record

ord-615c0bb89fa34ca683928352e7c73563

Source dataset

uspto-grants-2008_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07419990B2