Trifluoroacetic acid → 2-(6,7-Dimethoxy-3,4-dihydro-1H-isoquinoline-2-sulfonylmethyl)-3-methyl-butyric Acid

2-Chlorosulfonylmethyl-3-methyl-butyric acid tert-butyl ester (1.0 ml of a 1M solution in dichloromethane) was added to a solution of 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline hydrochloride (230 mg) and triethylamine (0.31 ml) in dichloromethane (10 ml) and the mixture stirred at room temperature for 16 h. Trifluoroacetic acid was added (5 ml) and the reaction left to stir for 2 h then diluted with hexane (10 ml) and evaporated under reduced pressure. The residue was azeotroped with 1:1 dichloromethane-hexane (2×10 ml), dissolved in 1M sodium hydroxide and washed with diethyl ether (2×10 ml) The aqueous was acidified to pH=4 with citric acid and extracted with ethyl acetate (2×15 ml). The combined extracts were washed with water (10 ml) and brine (10 ml), dried (Na2SO4), filtered and evaporated under reduced pressure to give the title compound (93 mg, 25%).

1. waitthe reaction left
2. stirringto stir for 2 h
3. customevaporated under reduced pressure
4. customThe residue was azeotroped with 1:1 dichloromethane-hexane (2×10 ml)
5. dissolutiondissolved in 1M sodium hydroxide
6. washwashed with diethyl ether (2×10 ml) The
7. extractionextracted with ethyl acetate (2×15 ml)
8. washThe combined extracts were washed with water (10 ml) and brine (10 ml)
9. dry with materialdried (Na2SO4)
10. filtrationfiltered
11. customevaporated under reduced pressure

ORD record

ord-585ce26746234207a13739d885a297f4

Source dataset

uspto-grants-2005_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06933306B2