Triisopropyl borate → Boronic acid, B-(2-(((1,1-dimethylethyl)amino)sulfonyl)phenyl)-

To (tert-butyl)(phenylsulfonyl)amine (17.43 g, 81.83 mmol) in 180 ml dry THF in an ice bath was added nBuLi (66 ml, 2.5M in hexanes) via addition funnel. Then triisopropyl borate (33 ml, 143.06 mmol) was added via addition funnel. The mixture was warmed to room temperature and allowed to stir for 4 hr. The reaction mixture was then cooled in an ice bath before HCL (82 ml, 3M) was added dropwise. This was allowed to stir at room temperature for 3 hr. The mixture was then put in the freezer over the weekend. The reaction was then warmed to room temperature and extracted with ether. The aqueous layers were washed twice more with ether. The combined organic layers were washed three times with 5M NaOH aqueous solution. The combined basic layers were acidified to pH=1 with 6M HCL solution. These acidified layers were then extracted three times with ether. These ether layers were then dried over MgSO4, filtered, then concentrated in vacuo to about 50 ml solution. To this solution was added hexanes and a minimal amount of ethyl acetate. A white precipitate is observed and the mixture in stored in the freezer to allow for crystallization. The white solid is then filtered and collected (14.65 g, 57mml, 70%) ES-MS(M+H)+=258.

1. additionvia addition funnel
2. temperatureThe reaction mixture was then cooled in an ice bath before HCL (82 ml, 3M)
3. additionwas added dropwise
4. stirringto stir at room temperature for 3 hr
5. temperatureThe reaction was then warmed to room temperature
6. extractionextracted with ether
7. washThe aqueous layers were washed twice more with ether
8. washThe combined organic layers were washed three times with 5M NaOH aqueous solution
9. extractionThese acidified layers were then extracted three times with ether
10. dry with materialThese ether layers were then dried over MgSO4
11. filtrationfiltered
12. concentrationconcentrated in vacuo to about 50 ml solution
13. additionTo this solution was added hexanes
14. customto allow for crystallization
15. filtrationThe white solid is then filtered
16. customcollected (14.65 g, 57mml, 70%)

ORD record

ord-b6c45bdd19c1445190bb8b3bb6cd4464

Source dataset

uspto-grants-2002_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06399627B1