Application of 1073-39-8, In the next few decades, the world population will flourish. As the population grows rapidly and people all over the world use more and more resources, all industries must consider their environmental impact. 1073-39-8, name is 3-Bromobicyclo[4.2.0]octa-1,3,5-triene belongs to bromides-buliding-blocks compound, it is a common compound, a new synthetic route is introduced below.
20 g (109 mmol) 2-(4-Bromophenyl)-cyclobutyl was dissolved in 150 ml dry THF and cooled to -78 C. 44 ml (109 mmol, 2.5 M solution) of n-Buli was added dropwise and the solution was stirred for one hour at -78 C. 2′- Bromo-biphenyl-2-carboxylic acid (43.6 mmol, 12.7 g) was dissolved in 25 ml THF and added to the n-BuLi solution at -78 C. The reaction mixture was stirred for 1 h at -78 C and then warmed to RT over the weekend. (0187) Ammoniumchloride solution was added to quench the reaction and the mixture was extracted with ethyl acetate. The combined organic phases were dried and the solvent was evaporated in vacuo. The resulting crude product was dissolved in 60 ml dry Toluene and 60 ml Hydrochloric acid (37%) as well as 1 15 ml acetic acid was added. The reaction was stirred at 80 C over night. After cooling down to RT the water was added, the aqueous phase was extracted with toluene and the combined organic phases were washed with water and dried with Na2SO4. The solvent was removed in vacuo. The resulting solid was recrystallized in (0188) Heptane/Toluene. 16 was obtained as a white product with 85% yield (0189) (37.1 mmol, 16.6 g). (0190) 5 I6 (15 g, 33.4 mmol), o-biphenylamine (6.2 g, 36.7 mmol) and Sodium-f- butylate (10.6 g, 1 10 mmol) were dissolved in 200 ml toluene. The mixture was degassed for 15 minutes and subsequently Pd(dppf)CI2 (1 .8 g, 2.2 (0191) mmol) was added. The solution was heated at reflux for 4 hours and then (0192) ^ Q cooled to RT. The mixture was filtered over Alox using toluene as the (0193) solvent. The resulting solid was recrystallized from toluene/heptanes. I7 was obtained as a white solid with a yield of 63% (1 1 .3 g, 21 mmol). (0194) 4.7 g (8.5 mmol) 2,7-dibromo-9,9-dioctyl-fluorene and 10 g (18.6 mmol, 2.2 1 eq) 17 were added to 100 ml Toluene. Subsequently 1 .5 g (1 .7 mmol, 0.2 (0195) eq) Pd2dba3 and 1 .6 g (17 mmol, 2 eq) Sodium-f-butylate were added and the mixture was degassed with argon. After 5 min degassing 3.8 g (1 .7 (0196) mmol, 0.2 eq) tri-f-butylphosphine was added and the reaction was stirred at reflux over the weekend. After cooling to RT the mixture was filtered over (0197) 20 (0198) Celite and subsequently purified via Soxhlet using Toluene as the solvent. (0199) The resulting solid was purified via flash chromatography. 9.7 g (6.6 mmol, 78%) of P8 was obtained.
The synthetic route of 3-Bromobicyclo[4.2.0]octa-1,3,5-triene has been constantly updated, and we look forward to future research findings.
Reference:
Patent; MERCK PATENT GMBH; SCHEIBLE, Katja Maria; ECKES, Fabrice; HEIL, Holger; BURKHART, Beate; JOOSTEN, Dominik; MONTENEGRO, Elvira; (93 pag.)WO2018/65357; (2018); A1;,
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