5-BROMO-BENZO[B]THIOPHEN-4-OL synthesis

Yield:34576-98-2 95.8%

Reaction Conditions:

with lithium carbonate in N,N-dimethyl-formamide at 100; for 6 h;Inert atmosphere;

Steps:

7 Embodiment 7:5-bromobenzo [b] thiophene -4-ol (IX) of preparation

inthe 250mL round bottom flask 5, 5- dibromo -6 7- Dihydrobenzo [b] thiophene-4 (5H)- ketone (IX) (9.6g, 31mmol) and DMF(100 ml). thesolution into adding lithium carbonate (14g, 186.mmol, 6eq) in nitrogen under thereaction mixture heated 100 °C reaction 6 hours. Then reaction solution was cooled toroom temperature and filtered Filtrateuse the water dilution use HC1 acidificationto pH= 1, and use ethyl acetate extraction.Theorganic phase with water and water washing concentrationand bycolumn chromatography purification (elutionagent ethylacetate ; petroleum ether =1;50)Obtain white solid . 6.82g,yield 95.8%.

References:

CN103254191,2016,B Location in patent:Paragraph 0097; 0098