4-Fluoroiodobenzene → 4-Acetyl-4'-fluoro-2-nitrobiphenyl

Participants

Reaction Steps

The starting material was prepared as follows. An Ullmann reaction using p-fluoroiodobenzene and 4-bromo-3-nitroacetophenone gave 4-acetyl-4'-fluoro-2-nitrobiphenyl, m.p. 88°-90°C., which was reduced with stannous chloride/hydrochloric acid to give 4-acetyl-2-amino-4'-fluorobiphenyl, m.p. 88°-91°C. This was subjected to the Schiemann reaction to give 4-acetyl-2,4'-difluorobiphenyl, m.p. 80°-82.5°C., which was subjected to the Willgerodt reaction using morpholine and sulphur, followed by hydrolysis, to give 2,4'-difluoro-4-biphenylylacetic acid, m.p. 144°-146°C. This was esterified to give the ethyl ester, b.p. 142°-146°C./0.35 mm., which was treated conventionally with diethyl carbonate, and then with dimethyl sulphate, to yield the required ethyl 2-(2,4'-difluoro-4-biphenylyl)-2-methylmalonate, b.p. 164°-166°C./0.05 mm.

Provenance & Evidence