Cyclohexylamine → 6-Bromo-2-cyclohexylamino-1-nitronaphthalene

HRID 1494360Notes

Reaction equation

HRID 1494360 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[C:8]([N+:12]([O-:14])=[O:13])=[C:7](OC)[CH:6]=[CH:5]2.[CH:17]1([NH2:23])[CH2:22][CH2:21][CH2:20][CH2:19][CH2:18]1>CN(C)C=O>[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[C:8]([N+:12]([O-:14])=[O:13])=[C:7]([NH:23][CH:17]1[CH2:22][CH2:21][CH2:20][CH2:19][CH2:18]1)[CH:6]=[CH:5]2

Participants

4

Reactant 2

HCID 7965CyclohexylamineHCID 220971876-Bromo-2-methoxy-1-nitronaphthalene

Product 1

HCID 198278506-Bromo-2-cyclohexylamino-1-nitronaphthaleneYield 84%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
120 °C

Procedure

A solution of 6-bromo-2-methoxy-1-nitronaphthalene (10.0 g, 35.6 mmol) and 8 ml of cyclohexylamine in 50 ml of dry N,N-dimethylformamide was heated with stirring at 120° C. for 17 h. The mixture was evaporated to dryness and the residue was triturated with 50 ml of ethanol at 0° C.. The solid was isolated by filtration and washed with light petroleum to give 10.4 g (84%) of 6-bromo-2-cyclohexylamino-1-nitronaphthalene. The crude product was suspended in 150 ml of 96% ethanol and hydrogenated at room temperature and 40 psi over Ni/Raney After the hydrogen uptake was completed, the reaction mixture was filtered into 50 ml of 4M hydrochloric acid and concentrated to dryness. Crude 1-amino-6-bromo-2-cyclohexylaminonaphthalene hydrochloride (9.8 g, 27.6 mmol) was taken up in 80 ml of dry tetrahydrofuran. Dry triethylamine (7.7 ml, 55.3 mmol) was added, followed by the dropwise addition of ethyloxalyl chloride (3.1 ml, 27.7 mmol) with stirring at 0° C.. The mixture was stirred over night at room temperature and finally at reflux for 4 h. The cooled mixture was filtered and the solid was washed with water and ethanol affording 5.2 g (51%) of the title compound M.p. 347.0° C. (N,N-dimethylformamide, DSC); IR (KBr): 1700 cm-1 ; 1H-NMR (DMSO-d6): 1.13-2.93 (m, 10H, 5CH2), 4.33-4.90 (m, 1H, NCH), 7.47-8.67 (m, 5H, ArH), 12.1 (broad s, 1H, NH); MS (m/z): 372 (M+, 17%).

Workup

  1. customThe mixture was evaporated to dryness
  2. customthe residue was triturated with 50 ml of ethanol at 0° C.
  3. customThe solid was isolated by filtration
  4. washwashed with light petroleum

Sources & evidence

ORD record
ord-1e786adb08d44e738cc06d63e046e0c7
Source dataset
uspto-grants-1991_06
Patent number
US05026704

Reaction notes

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