tert-Butanol → (6-Fluoro-quinolin-3-yl)carbamic acid tert-butyl ester

Reaction equation

[F:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[N:8]=[CH:7][C:6](C(O)=O)=[CH:5]2.C1(P(N=[N+]=[N-])(C2C=CC=CC=2)=[O:22])C=CC=CC=1.C([N:35]([CH:38](C)C)CC)(C)C.[C:41]([OH:45])([CH3:44])([CH3:43])[CH3:42]>>[C:41]([O:45][C:38](=[O:22])[NH:35][C:6]1[CH:7]=[N:8][C:9]2[C:4]([CH:5]=1)=[CH:3][C:2]([F:1])=[CH:11][CH:10]=2)([CH3:44])([CH3:43])[CH3:42]

Participants

Reactant 4

HCID 6386tert-Butanol

HCID 81531Diisopropylethylamine

HCID 199401P,P-Diphenylphosphinic azide

HCID 170396166-Fluoroquinoline-3-carboxylic acid

Product 1

HCID 66815651(6-Fluoro-quinolin-3-yl)carbamic acid tert-butyl ester

Procedure

A solution of 6-fluoro-quinoline-3-carboxylic acid (1.7 g, 8.89 mmol), diphenylphosphoryl azide (2.3 mL, 10.7 mmol) and diisopropylethylamine (4.65 mL, 26.67 mmol) in t-butanol (40 mL) was heated at reflux for 1 hour. The solution was cooled to room temperature, and the solvent was evaporated in vacuo. The residue was partitioned between aqueous sodium bicarbonate and dichloromethane. The organic layer was dried over sodium sulfate, and the product was preabsorbed onto silica gel. Purification by flash chromatography, using a gradient of ethyl acetate (0% to 30%) in heptane as the eluant, to give the product as a colorless solid, 1.3 g (56%). MS: m/z 263.0 (MH+).