Trifluoromethanesulfonic anhydride → 5-Bromo-2-pentyl-3,4-dihydroisoquinolin-1(2H)-one

HRID 387638Notes

Reaction equation

HRID 387638 reaction equation
C[O:2][C:3](=O)[N:4]([CH2:10][CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][C:13]=1[Br:18])[CH2:5][CH2:6][CH2:7][CH2:8][CH3:9].FC(F)(F)S(OS(C(F)(F)F)(=O)=O)(=O)=O>ClCCl.CN(C)C1C=CN=CC=1>[Br:18][C:13]1[CH:14]=[CH:15][CH:16]=[C:17]2[C:12]=1[CH2:11][CH2:10][N:4]([CH2:5][CH2:6][CH2:7][CH2:8][CH3:9])[C:3]2=[O:2]

Participants

5

Reactant 2

HCID 67749Trifluoromethanesulfonic anhydrideHCID 68473838Methyl[2-(2-bromophenyl)ethyl]pentylcarbamate

Product 1

HCID 684704205-Bromo-2-pentyl-3,4-dihydroisoquinolin-1(2H)-one

Reagents, catalysts & solvents 2

HCID 142844-(Dimethylamino)pyridineCatalystHCID 6344DichloromethaneSolvent2×

Conditions

Temperature
0 °C

Procedure

5.44 g of methyl[2-(2-bromophenyl)ethyl]pentylcarbamate are dissolved, under an inert atmosphere, in 200 cm3 of dichloromethane at a temperature close to 20° C. 6.07 g of 4-dimethylaminopyridine are added to the reaction mixture. It is cooled to a temperature in the vicinity of 0° C. 13.94 cm3 of trifluoromethanesulfonic anhydride are poured into the reaction mixture over 15 min. The suspension is kept stirring for 4 h at a temperature close to 20° C. Dichloromethane and also 50 cm3 of a water/ice mixture are added to the reaction medium. The 4-dimethylaminopyridine is filtered. The filtrate is decanted, the aqueous phase is extracted with dichloromethane. The organic phases are combined, washed with a saturated aqueous solution of sodium chloride, dried over magnesium sulfate and concentrated using a rotary evaporator under reduced pressure (5 kPa). The crude product obtained is purified by flash chromatography over silica (column: 200 g; particle size: 15-40 μm; eluent: 90% dichloromethane/10% ethyl acetate). After concentrating the fractions under reduced pressure, 4.14 g of 5-bromo-2-pentyl-3,4-dihydroisoquinolin-1(2H)-one are obtained in the form of a colorless oil.

Workup

  1. customclose to 20° C
  2. customclose to 20° C
  3. filtrationThe 4-dimethylaminopyridine is filtered
  4. customThe filtrate is decanted
  5. extractionthe aqueous phase is extracted with dichloromethane
  6. washwashed with a saturated aqueous solution of sodium chloride
  7. dry with materialdried over magnesium sulfate
  8. concentrationconcentrated
  9. customa rotary evaporator under reduced pressure (5 kPa)

Sources & evidence

ORD record
ord-b021342120464d7083398fd47ad607bd
Source dataset
uspto-grants-2013_02
Patent number
US08372864B2

Reaction notes

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