Rotenone (3.0 g) in dry dichloromethane (15mL) was added to boron tribromide
(1.45 mL) in dichloromethane (15 mL), kept below -5 AdegC.
The development of the cerium tribromide
(Ce[Br.sub.3]) gamma-ray detector among the lanthanum halide detector series (La[Br.sub.3]:Ce and La[Cl.sub.3]:Ce detectors) is one such example [4-11].
([greater than or equal to] 99%) was purchased from Acros; 4,4'-difluorobenzophenone ([greater than or equal to] 97%) was purchased from Yanji Chemical Plant and distilled before use; 4,4'-bismaleimidodiphenylmethane (BMDM, [greater than or equal to] 95%) was purchased from Hengxing Chemical Industrial Technology Company; 5-methoxyresorcinol ([greater than or equal to] 98%), 3,5-dimethoxyphenol ([greater than or equal to] 99%), and 2,2'-diallylbisphenol A (DBA, [greater than or equal to] 85%) were purchased from Sigma-Aldrich.
Finally, the demethylation was carried out using boron tribromide
in dichloromethane at room temperature to give the required 2-TB-8-hq in 66% yield.
Onciu, "A novel approach in cinnamic acid synthesis: direct synthesis of cinnamic acids from aromatic aldehydes and aliphatic carboxylic acids in the presence of boron tribromide
," Molecules, vol.
The starting materials such as 7-methoxy-2,3-dihydro-[sup.1]H-inden-1-one (6), N-bromosuccinimide (NBS), 2,2,-azobisisobutyronitrile (AIBN), triethylamine, [alpha], [alpha], [alpha]' [alpha]',-tetrabromo-o-xylene, sodium iodide, boron tribromide
, tert-butyl chloride, and aluminum trichloride were purchased from Merck, ACROS, and Sigma-Aldrich.
To a solution of compound 15a (1.5 g, 6.38 mmol) in dichloromethane (15 mL), phosphorous tribromide
(2.59 g, 9.57 mmol) was added at 0[degrees]C under nitrogen atmosphere.
A new synthetic protocol developed by a research team from UNIST, a leading Korean university, has revealed that boron/nitrogen co-doping is only feasible when carbon tetrachloride (CCl4) is treated with boron tribromide
(BBr3) and nitrogen (N2) gas.
Intramolecular cyclization was achieved through the reaction of the isoxazole ring with pyridinium tribromide
. The proposed mechanism of intramolecular cyclization involves the activation of the isoxazoline ring with bromine to form a bromonium ion.
The methyl ether in 10 was deprotected with boron tribromide
with reaction temperatures belowC0 to liber ate phenol 11 (yields 35%-50%).
"Bromination of Alkenes and Related Compounds by Use of Benzyltrimethylammonium Tribromide
in Aprotic and Protic Solvents".