Sulfuric Acid → 6-Bromo-2-(toluene-4-sulfonyl)-1,2,3,4-tetrahydro-isoquinoline

To a stirred solution of sulfuric acid (60% w/w, 20 g) in 32 mL of toluene at r.t. was added 7.60 g of N-[2-(3-bromo-phenyl)-ethyl]-4-methyl-benzenesulfonamide, followed by 32 mL of dimethoxymethane. The reaction mixture was heated over an oil bath set at 50° C. externally with stirring under nitrogen for 15 h. LC/MS: retention time=4.549 min, MS 366/368. TLC (DCM): SM Rf=0.35, product Rf=0.65. The reaction was complete as judged by TLC. The reaction mixture was cooled to r. t. and diluted with ether (100 mL). The two layers were separated and the aqueous layer was extracted with ether (25 mL). The combined ethereal solution was washed with water (25 mL), saturated sodium bicarbonate (25 mL) and brine (20 mL), sequentially. Then, the ethereal solution was dried over anhydrous granular potassium carbonate, filtered, and concentrated in vacuo. The crude product, a solid after standing, was re-crystallized from ether (75 mL) and pentane (100 mL). The material was collected by suction filtration and dried under vacuum to obtain 6.6 g (90%) of the title compound as a white crystalline solid:

1. temperatureThe reaction mixture was heated over an oil bath
2. customset at 50° C.
3. temperatureThe reaction mixture was cooled
4. customThe two layers were separated
5. extractionthe aqueous layer was extracted with ether (25 mL)
6. washThe combined ethereal solution was washed with water (25 mL), saturated sodium bicarbonate (25 mL) and brine (20 mL)
7. dry with materialThen, the ethereal solution was dried over anhydrous granular potassium carbonate
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. customwas re-crystallized from ether (75 mL) and pentane (100 mL)
11. filtrationThe material was collected by suction filtration
12. customdried under vacuum

ORD-Eintrag

ord-23fe108184c54e26af66f08245065ef1

Quelldatensatz

uspto-grants-2014_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08871788B2