6921-66-0

Preparation by Fries rearrangement of 3-chlorophenyl acetate with aluminium chloride,
without solvent at 130–135° (74–75%) ], between 135° and 200° and 175–200° (85–89%)
with solvent, at r.t., in nitrobenzene (88%), in tetrachloroethane (50%) or in chlorobenzene.

The general procedure for the synthesis of 4'-chloro-2'-hydroxyacetophenone and 1-(4-chloro-3-hydroxyphenyl)ethanone from p-chloroacetophenone was as follows: 5 mL of acetonitrile was added to the reaction system as a solvent under the protection of an Ar atmosphere, followed by the addition of 2.69 mg (1 × 10^-2 mmol) of 1-methyl-3-cyanoquinoline salt as a photosensitizer and 2.80 mg (6 × 10^ -3 mmol) cobalt oxime complex 2 as cobalt catalyst. Next, 0.2 mmol of 4'-chloroacetophenone (where R1 is COCH3, R4 is Cl, and both R2 and R3 are H) and 2 mmol of H2O were added. the reaction was carried out at room temperature using a high-pressure mercury lamp irradiation for 5 hr. Upon completion of the reaction, the production of H2 was detected by gas chromatography (TCD) and the conversion of benzene was analyzed by gas chromatography (FID). Subsequently, the products were separated by column chromatography and identified using 1H NMR and mass spectrometry (MS) to confirm that the main products were 4'-chloro-2'-hydroxyacetophenone and 4'-chloro-3'-hydroxyacetophenone. The conversion of 4'-chloroacetophenone was 56%, with yields of 14% and 42% for 4'-chloro-2'-hydroxyacetophenone and 4'-chloro-3'-hydroxyacetophenone, respectively, and 56% for H2.

[1] Patent: CN107324975, 2017, A. Location in patent: Paragraph 0128-0129