Carbon tetrabromide → HCID 178509439, compound

HRID 489431Notes

Reaction equation

HRID 489431 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[CH:8]1[C:13]([C:14]#[N:15])=[C:12]([CH2:16]O)[NH:11][C:10]2=[N:18][NH:19][CH:20]=[C:9]12.C(Br)(Br)(Br)[Br:22].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>C(Cl)Cl>[Cl:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[CH:8]1[C:13]([C:14]#[N:15])=[C:12]([CH2:16][Br:22])[NH:11][C:10]2=[N:18][NH:19][CH:20]=[C:9]12

Participants

5

Reactant 3

HCID 11205Carbon tetrabromideHCID 11776TriphenylphosphineHCID 178510265HCID 178510265, compound

Product 1

HCID 178509439HCID 178509439, compoundYield 36.9%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

4-(2-Chlorophenyl)-5-cyano-6-(t-butyldimethylsilyloxy)-methyl-4,7-dihydro-2H-pyrazolo[3,4-b]pyridine was prepared from ethyl t-butyldimethylsilyloxyacetate, 2-chlorobenzaldehyde and 3-aminopyrazole in the same manner as in Example 94. To a solution of 4-(2-chlorophenyl)-5-cyano-6-(t-butyldimethylsilyloxy)methyl-4,7-dihydro-2H-pyrazolo[3,4-b]pyridine (10 g) in tetrahydrofuran (100 ml) was added a THF solution (24.9 ml) of 1.0 M tetrabutylammonium fluoride and the mixture was stirred at room temperature for 1 hour. To the reaction mixture was added ethyl acetate (200 ml), and the resulting mixture was washed with a saturated aqueous sodium chloride solution and dried over anhydrous magnesium sulfate. The solvent was evaporated and the obtained residue was crystallized from ethyl acetate to give 4-(2-chlorophenyl)-5-cyano-6-hydroxymethyl-4,7-dihydro-2H-pyrazolo[3,4-b]pyridine (5.46 g) as a white solid. To a solution of 4-(2-chlorophenyl)-5-cyano-6-hydroxymethyl-4,7-dihydro-2H-pyrazolo[3,4-b]pyridine (1.0 g) and carbon tetrabromide (1.27 g) in methylene chloride (35 ml) was added triphenylphosphine (1.0 g) under ice-cooling and the mixture was stirred under ice-cooling for 4 hours. The reaction mixture was concentrated under reduced pressure and the obtained residue was purified by silica gel column chromatography (eluent:hexane-ethyl acetate (1:1)) to give 4-(2-chlorophenyl)-5-cyano-6-bromomethyl-4,7-dihydro-2H-pyrazolo[3,4-b]pyridine (0.45 g) as a pale-yellow solid. To a suspension of sodium hydride (25 mg) in DMF (3 ml) was added 1-methylpiperazine (69 μl) and the mixture was stirred at room temperature for 30 minutes. To this reaction mixture was added a solution of 4-(2-chlorophenyl)-5-cyano-6-bromomethyl-4,7-dihydro-2H-pyrazolo[3,4-b]pyridine (200 mg) in DMF (3 ml) under ice-cooling and the mixture was stirred under ice-cooling for 1 hour. To the reaction mixture was added water and the mixture was extracted with ethyl acetate. The extract was washed with a saturated aqueous sodium chloride solution and dried over anhydrous magnesium sulfate. The solvent was evaporated and the obtained residue was purified by silica gel column chromatography (eluent:ethyl acetate-methanol (4:1)). The obtained oil was treated with hydrogen chloride-methanol to give the title compound (87 mg) as white crystals.

Workup

  1. temperaturecooling
  2. temperaturecooling for 4 hours
  3. concentrationThe reaction mixture was concentrated under reduced pressure
  4. customthe obtained residue was purified by silica gel column chromatography (eluent:hexane-ethyl acetate (1:1))

Sources & evidence

ORD record
ord-b404e6fa21274afc9e486c1e869c6def
Source dataset
uspto-grants-2005_12
Patent number
US06977262B2

Reaction notes

Loading…