Methanol → 2-Bromo-1-(4-fluorophenyl)ethanone O-methyloxime

Temperature

60 °C

A 2.0 L round bottom flask was charged with 4-fluorophenacyl bromide (97.6 g, 450 mmol), then methanol (750 mL), then O-methylhydroxylamine hydrochloride (75.1 g, 899 mol), and the mixture was heated to 65° C. for 2 hours. The reaction mixture was then concentrated under reduced pressure, charged with acetone (750 mL), and lithium bromide (195 g, 2.25 mol), and heated to 60° C. for 15 hours. The reaction mixture was then concentrated under reduced pressure, suspended in 1.0 L methylene chloride, and washed with 3×200 mL water. The aqueous extracts were then pooled and back-extracted with 2×200 mL methylene chloride. All organic extracts were then pooled, dried over Na2SO4, filtered, and concentrated under reduced pressure to yield O-methyloxime 30. Yield of 30: 92.3 g (83%). 1H NMR (500 MHz, CDCl3) δ 4.10 (s, 3H), 4.35 (s, 2H), 7.11 (t, J=8.8 Hz, 2H), 7.72 (m, 2H). MS (ESI+) 246.0.

1. concentrationThe reaction mixture was then concentrated under reduced pressure
2. concentrationThe reaction mixture was then concentrated under reduced pressure
3. washwashed with 3×200 mL water
4. extractionback-extracted with 2×200 mL methylene chloride
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure

ORD record

ord-e52defd2a44444dfab7e49ae98a8d258

Source dataset

uspto-grants-2009_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07504501B2