p-(Trifluoromethoxy)phenyl isocyanate → Tert-butyl 4-(trifluoromethoxy)phenylcarbamate

A mechanically stirred solution of 4-(trifluoromethoxy)phenyl isocyanate (10.54 g, 51.9 mmol) in THF (200 mL) at 0° C. was treated with the dropwise addition of 1.0 M potassium tert-butoxide solution in THF (55 mL, 55 mmol). The solution was allowed to come to room temperature, and stirred overnight. The mixture was diluted with diethyl ether (300 mL), washed successively with saturated ammonium chloride solution (2×100 mL), water (100 mL), and brine (100 mL), dried over sodium sulfate, and concentrated in-vacuo. The residue was combined with material from a previous reaction (5.4 g scale), and purified over silica gel, eluting with 10%-20%-50% ethyl acetate/hexanes to yield 20.0 g of an off-white solid as product. 1H NMR (400 MHz, DMSO) δ ppm 1.48 (s, 9 H) 7.26 (d, J=8.35 Hz, 2 H) 7.54 (d, J=8.79 Hz, 2 H) 9.56 (s, 1 H).

1. customto come to room temperature
2. washwashed successively with saturated ammonium chloride solution (2×100 mL), water (100 mL), and brine (100 mL)
3. dry with materialdried over sodium sulfate
4. concentrationconcentrated in-vacuo
5. customThe residue was combined with material from a previous reaction (5.4 g scale)
6. custompurified over silica gel
7. washeluting with 10%-20%-50% ethyl acetate/hexanes

ORD record

ord-a8a0ec84f1dc4addb28f6a51d5a25c35

Source dataset

uspto-grants-2007_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07291615B2