Hydrochloric Acid → 1-Cyclohexyl-3-ethyl-6-fluoro-1H-indazole

HRID 612844Notes

Reaction equation

HRID 612844 reaction equation
F[C:2]1[CH:7]=[C:6]([F:8])[CH:5]=[CH:4][C:3]=1[C:9](=O)[CH2:10][CH3:11].C([O-])(=O)C.[Na+].S(O)(=O)(=O)C.[CH:23]1([NH:29][NH2:30])[CH2:28][CH2:27][CH2:26][CH2:25][CH2:24]1.Cl>C1(C)C=CC=CC=1>[CH:23]1([N:29]2[C:2]3[C:3](=[CH:4][CH:5]=[C:6]([F:8])[CH:7]=3)[C:9]([CH2:10][CH3:11])=[N:30]2)[CH2:28][CH2:27][CH2:26][CH2:25][CH2:24]1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 1235862',4'-DifluoropropiophenoneHCID 517045Sodium AcetateHCID 22009940Cyclohexylhydrazine mesylate

Product 1

HCID 98596991-Cyclohexyl-3-ethyl-6-fluoro-1H-indazoleYield 98%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

To a solution of 1-(2,4-difluoro-phenyl)-propan-1-one (21.29 g, 125.1 mmol) in toluene (120 mL) was added sodium acetate (26.75 g, 326.1 mmol) and cyclohexylhydrazine mesylate (34.0 g, 163 mmol). The reaction mixture was heated to reflux in a Dean-Stark apparatus for 12 hours. The reaction was cooled to room temperature and poured into 1 N hydrochloric acid (100 mL). The toluene layer was separated and washed with water (75 mL) and brine (75 mL). The organic layer was dried over magnesium sulfate, filtered, and concentrated to yield 30.07 g of 1-cyclohexyl-3-ethyl-6-fluoro-1H-indazole (98% yield). 1H NMR (400 MHz, CDCl3) d 1.33 (t, 3, J=7.7), 1.35-1.44 (m, 2), 1.47-1.96 (m, 8), 2.93 (q, 2, J=7.7), 4.14-4.22 (m, 1), 6.81 (dt, 1, J=8.9, 2.1), 6.99 (dd, 1, J=9.8, 2.1), 7.40 (ddd, 1, J=8.7, 5.2, 0.4). 13C NMR (100 MHz, CDCl3) d 13.97, 20.53, 25.37, 25.84, 32.32, 58.18, 94.77 (d, J=27.4), 109.11 (d, J=26.0), 119.38, 121.75 (d, J=11.5), 139.89 (d, J=13.0), 146.61, 161.95 (d, J=242).

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureto reflux in a Dean-Stark apparatus for 12 hours
  3. customThe toluene layer was separated
  4. washwashed with water (75 mL) and brine (75 mL)
  5. dry with materialThe organic layer was dried over magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-db61696e0bf84900b117dc58b2730888
Source dataset
uspto-grants-1999_12
Patent number
US06005118

Reaction notes

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