4,4'-Dibromobiphenyl → 1-Bromonaphthalene

Participants

Reaction Steps

4,4'-Biphenylene-bis- (1-naphthyl-phosphinous acid 2,4-di-tert-butylphenyl ester): in deviation from the general instructions, 200 mmol (=62.4 g) of 4,4'-dibromobiphenyl were subjected to a Grignard reaction with 600 mmol (=14.6 g) of magnesium filings in 600 ml of tetrahydrofuran under the action of ultrasound (40 kHz), and the product was then reacted with 400 mmol (=122.9 g) of phosphorous acid 2,4-di-tert-butylphenyl ester-dichloride in 700 ml of tetrahydrofuran/heptane=1/6. The Grignard reagent obtained from 82.8 g (400 mmol) of 1-bromonaphthalene was added dropwise to the resulting suspension. The mixture was filtered and the filtrate was concentrated in vacuo to give 175 g of yellow resin having a content of 76% of the above compound 31P-NMR: δ(CDCl103.7 ppm]. Pale yellow crystals of melting point 255° C. crystallized from acetone.

Provenance & Evidence