Adding a certain compound to certain chemical reactions, such as: 3722-78-9, name is 8-Bromochroman, belongs to bromides-buliding-blocks compound, can increase the reaction rate and produce products with better performance than those obtained under traditional synthetic methods. Here is a downstream synthesis route of the compound 3722-78-9, Safety of 8-Bromochroman
EXAMPLE 20 4,5-bis-(4-Chloro-phenyl)-2-chroman-8-yl-4,5-dihydro-1H-imidazole To a solution of 8-bromo-chroman (1.434 g, 6.730 mmol, prepared from 2,6-dibromo-phenol using the procedure reported by Thomas, G. H. et al. Tetrahedron Lett. 1998, 39, 2219-22) in dimethylformamide (10 mL) at room temperature was added zinc cyanide (790 mg, 6.730 mmol). The mixture was degassed by passing argon through for 2 h before tetrakis(triphenylphosphine)palladium (778 mg, 0.673 mmol) was added. The reaction mixture was heated at 90 C. for 12 h. Upon cooling to room temperature, it was diluted with diethyl ether (100 mL) and washed with sodium bicarbonate, brine and dried over anhydrous sodium sulfate. The solid was filtered off, and the filtrate was concentrated in vacuo. Purification of the crude residue by flash chromatography (Biotage system, KP-Sil 32-63 mum, 60 A silica gel) eluding with 10-20% ethyl acetate in hexanes yielded chroman-8-carbonitrile (370 mg, 35%). Hydrogen chloride gas was passed through a solution of chroman-8-carbonitrile (370 mg, 1.736 mmol) in anhydrous ethanol (15 mL) at 0 C. After 1 h, hydrogen chloride gas was stopped and the reaction vessel was sealed with a stopper. After stirring at room temperature for 1 d, the reaction vessel was cooled to 0 C. and the stopper was removed. The solvent was evaporated in vacuo to afford chroman-8-carboximidic acid ethyl ester hydrochloride (491 mg, 88%). It was used without further purification. A solution of meso-1,2-bis-(4-chloro-phenyl)-ethane-1,2-diamine (352 mg, 1.25 mmol), chroman-8-carboximidic acid ethyl ester hydrochloride (491 mg, 2.031 mmol) and triethylamine (350 muL, 2.5 mmol) in ethanol (10 mL) was heated at reflux for 12 h. The solvent was removed and the residue was purified by flash chromatography (Biotage system, KP-Sil 32-63 mum, 60 A silica gel) eluding with 0-5% methanol in ethyl acetate to afford 4,5-bis-(4-chloro-phenyl)-2-chroman-8-yl-4,5-dihydro-1H-imidazole as an off-white foam (189 mg, 36%). HR-MS (ES, m/z) calculated for C24H21N2OCl2 [(M+H)+] 423.126, observed 423.1026.
In the field of chemistry, the synthetic routes of compounds are constantly being developed and updated. I will also mention this compound in other articles, 8-Bromochroman, other downstream synthetic routes, hurry up and to see.
Reference:
Patent; Hoffmann-La Roche Inc.; US6617346; (2003); B1;,
Bromide – Wikipedia,
bromide – Wiktionary