4-Bromotoluene → 4-(4-Methylphenyl)benzoxazole

a 500 mL 2-neck round-bottomed flask was equipped with a reflux condenser and replaced by nitrogen. 70 mL of THF that was dried with 0.11 mol of Mg metal was added to the above flask and then, 0.10 mol of 1-bromo-4-methylbenzene was added in a dropwise fashion. The reaction was significantly exodermic and thus a cooling bath was equipped to reduce the temperature inside the reactor less than 50° C. It was agitated for 2 hours at room temperature, 0.11 mol of zinc chloride was added with 100 mL of THF, and further agitated for 2 hours to obtain a slurry-phase reaction mixture. Another flask was replaced by nitrogen and then 0.10 mol of 4-chlorobenzo[d]oxazole derivative, 0.10 mol of Pd, and 3 mol % of Pd(PPh3)4 were dissolved in 100 mL of THF. The prepared solution was added to the reaction mixture and then agitated 60° C. for 24 hours. After the reaction is complete, the resulting product was placed on a silica gel column to remove an inorganic slurry, and then a THF solution was concentrated under vacuum to obtain 4-para-tolylbenzo[d]oxazole using column chromatography at a yield of 91%.

1. customa 500 mL 2-neck round-bottomed flask was equipped with a reflux condenser
2. additionwas added to the above flask
3. customthus a cooling bath was equipped
4. custominside the reactor less than 50° C
5. stirringfurther agitated for 2 hours
6. customto obtain
7. customa slurry-phase reaction mixture
8. customAnother flask was replaced by nitrogen
9. additionThe prepared solution was added to the reaction mixture
10. stirringagitated 60° C. for 24 hours
11. customto remove an inorganic slurry
12. concentrationa THF solution was concentrated under vacuum

ORD record

ord-80436a37505345cbafd39c8889b76b19

Source dataset

uspto-grants-2011_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07939669B2