N,N-Diethylaniline → 3-bromo-2-(4-chlorophenyl)-4,5,6,7-tetrahydro-2H-indazole

HRID 2419976Notes

Reaction equation

HRID 2419976 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([N:8]2[C:16](=O)[C:15]3[CH2:14][CH2:13][CH2:12][CH2:11][C:10]=3[NH:9]2)=[CH:4][CH:3]=1.C(N(CC)C1C=CC=CC=1)C.P(Br)(Br)([Br:31])=O>CN(C)C=O>[Br:31][C:16]1[N:8]([C:5]2[CH:6]=[CH:7][C:2]([Cl:1])=[CH:3][CH:4]=2)[N:9]=[C:10]2[C:15]=1[CH2:14][CH2:13][CH2:12][CH2:11]2

Participants

5

Reactant 3

HCID 7061N,N-DiethylanilineHCID 24613Phosphorus oxybromideHCID 164906132-(4-chlorophenyl)-4,5,6,7-tetrahydro-2H-indazol-3-ol

Product 1

HCID 203091073-bromo-2-(4-chlorophenyl)-4,5,6,7-tetrahydro-2H-indazole

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To 5.0 parts of 2-(4-chlorophenyl)-1,2,4,5,6,7-hexahydro-3H-indazol-3-one [from Example 1(c)] with 3.0 parts of N,N-diethylaniline and 5.0 parts of dimethylformamide under nitrogen atmosphere was added 6.3 parts of phosphorous oxybromide. The mixture was heated to 130°-170° for 2 hours. After cooling to room temperature, the reaction mixture was extracted with 100 parts of diethyl ether, washed with water, dried over anhydrous magnesium sulfate and concentrated on a rotary evaporator. Recrystallization from methanol/water gave 2.7 parts of product, m.p. 101°-102°.

Workup

  1. temperatureThe mixture was heated to 130°-170° for 2 hours
  2. extractionthe reaction mixture was extracted with 100 parts of diethyl ether
  3. washwashed with water
  4. dry with materialdried over anhydrous magnesium sulfate
  5. concentrationconcentrated on a rotary evaporator
  6. customRecrystallization from methanol/water
  7. customgave 2.7 parts of product, m.p. 101°-102°

Sources & evidence

ORD record
ord-16328c95ec2c42158e4fc04f91bb000a
Source dataset
uspto-grants-1978_08
Patent number
US04108628

Reaction notes

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