1-Bromo-4-trityl-benzene synthesis

Yield: 86%

Reaction Conditions:

Stage #1:4-tritylaniline with hydrogen bromide;sodium nitrite in water;acetoneCooling with ice bath;
Stage #2: with hydrogen bromide;copper(I) bromide in water;acetone at 20;Cooling with ice bath;

Steps:

1
Synthesis of 4-tritylbromobenzene 25 parts by weight of 4-tritylaniline, 400 parts by weight of acetone, and 162 parts by weight of hydrobromic acid were put into a reaction vessel and stirred. While cooling the vessel in an ice bath, a solution of 7 parts by weight of sodium nitrite dissolved in 100 parts by weight of water was slowly added dropwise thereto. After the dropwise addition was complete, stirring was carried out for 30 minutes in an ice bath. Slowly added dropwise to this solution in an ice bath was a solution of 17.4 parts by weight of copper (I) bromide that had been dissolved in 31.5 parts by weight of hydrobromic acid. After the dropwise addition was complete, stirring was carried out at room temperature for 2 hours. After the reaction, a precipitate deposited in the reaction solution was collected by filtration, thus giving 25.8 parts by weight of 4-tritylbromobenzene (yield: 86%). ¹H-NMR (CDCl₃) δ=7.00 (d, 2H), 7.10-7.30 (m, 15H), 7.38 (d, 2H).

References:

FUJIFILM Corporation US2009/227812, 2009, A1 Location in patent:Page/Page column 9