3,4'-DIBROMOBENZOPHENONE synthesis

5synthesis methods

Product Name:3,4'-DIBROMOBENZOPHENONE
CAS Number:83699-51-8
Molecular formula:C13H8Br2O
Molecular Weight:340.01

22037-28-1
329 suppliers
$24.00/5g

922-65-6 Synthesis

922-65-6
137 suppliers
$22.00/1g

3988-03-2 Synthesis

3988-03-2
214 suppliers
$6.00/1g

83699-51-8
13 suppliers
$126.00/1g

Yield:3988-03-2 30 mg ，83699-51-8 3 mg

Reaction Conditions:

Stage #1: divinylcarbinolwith 2,3-dicyano-5,6-dichloro-p-benzoquinone in dichloromethane at 25; for 18 h;Schlenk technique;Inert atmosphere;Diels-Alder Cycloaddition;
Stage #2: 3-bromofuranewith magnesium iodide in dichloromethane at 0; for 18 h;Schlenk technique;Inert atmosphere;Diels-Alder Cycloaddition;
Stage #3: with sodium methylate in methanol;dimethyl sulfoxide at 20; for 2 h;Temperature;Solvent;Reagent/catalyst;

Steps:

b1 bl) Aromatization of the double Diels-Alder adducts

In a carousel tube fitted with a PTFE septum screw cap, Diels-Alder adducts from the example a) (206 mg, 0.46 mmol), dimethyl sulfoxide (1.5 ml) and sodium methoxide solution (25 wt. % in methanol; 41 mg; 0.19 mmol) were charged. The reaction mixture was stirred at room temperature during 2 hours. 1H NMR (DMSO-d6) show the conversion of the cycloadducts and the formation of dibromobenzophenone (d 7.78, (d, J= 8.8 Hz), 7.67 (d, J=8.8Hz)). GC analysis calibrated with the commercial product show the formation of 30 mg of 4,4’-dibromobenzophenone and 3 mg of 3,4’- dibromobenzophenone, corresponding to a yield of 21 % for those 2 products.

References:

WO2019/106197,2019,A1 Location in patent:Page/Page column 12-13