1423-61-6 7-Bromobenzo[b]thiophene 12045538, abenzothiophene compound, is more and more widely used in various fields.
With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.1423-61-6,7-Bromobenzo[b]thiophene,as a common compound, the synthetic route is as follows.
Combine 7-bromobenzo[b]thiophene (300 g, 1.41 mmol) and tri- isopropylborate (403.6 g, 2.15 mmol) in anhydrous THF (4 L) in a 12-L Morton flask fitted with a mechanical stirrer and cool under nitrogen in a dry-ice/acetone bath to – 70 0C. Add M-butyl lithium (1.6 M in hexane, 714 g, 1.68 mmol) dropwise at such a rate as to keep the internal temperature less than -67.5 0C. After the addition is complete allow the reaction mixture to stir at this temperature for 1 h. Remove the cooling bath and slowly add 4 L of water, which causes the temperature to rise to about -5 0C. Next, add concentrated HCl (75 mL) until the pH of the solution is about pH = 2. Allow the slurry to stir for 1 h. Add sufficient 5 N aqueous NaOH to adjust the pH of the mixture to about pH = 12 and transfer to a 22-L bottom-drop funnel. Separate and save the lower aqueous layer. Dilute the upper organic layer with 4 L of methyl-tert-butyl ether and extract with 1 L of 5 N aqueous NaOH. Separate the aqueous layer, combine with the previous aqueous extract and place back in the separatory funnel. Wash the aqueous layer with additional methyl-tert-butyl ether (4 L). Again, separate the aqueous layer and transfer to a 12-L, 3 -neck round bottom flask fitted with a mechanical stirrer. Cool the solution to +5 0C with an ice-water bath. Add concentrated HCl slowly until the pH of the solution is about pH = 2. Stir the mixture for 30 minutes and then filter off the resulting solid. Rinse the solid on the funnel twice with 2 L of water and allow to air-dry for 30 min. Place the solid in a vacuum oven at 50 0C and dry under vacuum overnight. The dried solid is slurried with 2 L of M-heptane for 30 min to remove the yellow color. Again filter off the solid, air-dry for 30 min and then vacuum-dry at 40 0C overnight to give the title compound (188.8 g, 75 %) as a white solid. 1H NMR (400 MHz, CD3OD) delta 7.86 (d, J= 8 Hz, IH), 7.49-7.57 (m, 2H), 7.30-7.39 (m, 2H)., 1423-61-6
1423-61-6 7-Bromobenzo[b]thiophene 12045538, abenzothiophene compound, is more and more widely used in various fields.
Reference£º
Patent; ELI LILLY AND COMPANY; WO2008/144223; (2008); A2;,
Benzothiophene – Wikipedia
Benzothiophene | C8H6S – PubChem