Potassium Carbonate → HCID 17981940, compound

HRID 2220331Notes

Reaction equation

HRID 2220331 reaction equation
Br[C:2]1[C:10]2[S:9][N:8]=[CH:7][C:6]=2[C:5]([O:11][CH3:12])=[CH:4][CH:3]=1.[C:13]([O-])([O-])=O.[K+].[K+].CB1OB(C)OB(C)O1>O1CCOCC1.O.ClCCl.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[CH3:12][O:11][C:5]1[C:6]2[CH:7]=[N:8][S:9][C:10]=2[C:2]([CH3:13])=[CH:3][CH:4]=1

Participants

8

Reactant 3

HCID 11430Potassium CarbonateHCID 574072TrimethylboroxineHCID 179819327-Bromo-4-methoxy-benzo[d]isothiazole

Product 1

HCID 17981940HCID 17981940, compoundYield 26.1%

Reagents, catalysts & solvents 4

HCID 178418397HCID 178418397, compoundCatalystHCID 962WaterSolventHCID 6344DichloromethaneSolventHCID 312751,4-DioxaneSolvent

Conditions

Temperature
110 °C

Procedure

A solution of 7-bromo-4-methoxy-benzo[d]isothiazole (460 mg, 1.88 mmol), K2CO3 (780 mg, 5.64 mmol), and Pd(PPh3)4 (217 mg, 0.188 mmol) in 1,4-dioxane (5 mL) was added trimethylboroxine (290 μL, 2.07 mmol) and the solution was heated to 110° C. for 18 h. The reaction was cooled to rt and diluted with water and dichloromethane. The organic phase was separated and the aqueous phase was extracted with 2×30 mL dichloromethane. The combined organic phases were dried (MgSO4) and concentrated in vacuo. The residue was purified by flash chromatography eluting silica gel with EtOAc:hexane [0:100 to 1:10] to yield 4-methoxy-7-methyl-benzo[d]isothiazole (88 mg, 26%). A method similar to that described for the preparation of benzo[d]isothiazol-4-ol (above) using 4-methoxy-7-methyl-benzo[d]isothiazole (88 mg, 0.491 mmol) and pyridine hydrochloride (567 mg, 5 mol) gave the title compound (30 mg, 37%): δH (300 MHz, CDCl3): 8.99 (1H, s), 7.15 (1H, d, J=7.5 Hz), 6.70 (1H, d, J=7.5 Hz), 2.45 (3H, s).

Workup

  1. temperatureThe reaction was cooled to rt
  2. customThe organic phase was separated
  3. extractionthe aqueous phase was extracted with 2×30 mL dichloromethane
  4. dry with materialThe combined organic phases were dried (MgSO4)
  5. concentrationconcentrated in vacuo
  6. customThe residue was purified by flash chromatography
  7. washeluting silica gel with EtOAc

Sources & evidence

ORD record
ord-cf390a9755a8441d899ed17da8f6445b
Source dataset
uspto-grants-2008_08
Patent number
US07417064B2

Reaction notes

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