Methanol → 5-(3,5-dimethylisoxazol-4-yl)-N'-hydroxy-1-(4-hydroxyphenyl)-3-methyl-1H-pyrazole-4-carboximidamide

HRID 1410127Notes

Reaction equation

HRID 1410127 reaction equation
Cl.[NH2:2][OH:3].C([O-])(O)=O.[Na+].CO.[CH3:11][C:12]1[C:16]([C:17]2[N:21]([C:22]3[CH:27]=[CH:26][C:25]([O:28]C)=[CH:24][CH:23]=3)[N:20]=[C:19]([CH3:30])[C:18]=2[C:31]#[N:32])=[C:15]([CH3:33])[O:14][N:13]=1>O.[Cl-].[Na+].O.CCOC(C)=O>[NH2:13][OH:14].[CH3:11][C:12]1[C:16]([C:17]2[N:21]([C:22]3[CH:23]=[CH:24][C:25]([OH:28])=[CH:26][CH:27]=3)[N:20]=[C:19]([CH3:30])[C:18]=2[C:31](=[N:2][OH:3])[NH2:32])=[C:15]([CH3:33])[O:14][N:13]=1

Participants

9

Reactant 4

HCID 887MethanolHCID 443297Hydroxyamine hydrochlorideHCID 516892Sodium BicarbonateHCID 671200255-(3,5-dimethylisoxazol-4-yl)-1-(4-methoxyphenyl)-3-methyl-1H-pyrazole-4-carbonitrile

Product 2

HCID 787HydroxylamineHCID 759521745-(3,5-dimethylisoxazol-4-yl)-N'-hydroxy-1-(4-hydroxyphenyl)-3-methyl-1H-pyrazole-4-carboximidamideYield 41.7%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 8857Ethyl AcetateSolventHCID 57417360Sodium chloride; waterSolvent

Conditions

Temperature
130 °C

Procedure

A hydroxylamine solution was prepared. Hydroxylamine-HCl (26 mg, 0.37 mmol) and NaHCO3 (32 mg, 0.37 mmol) dissolved in water (0.2 mL), methanol (0.4 mL) was stirred 2 min until gas ceased to evolve, the mixture was filtered and degassed (N2). This was added to the 5-(3,5-dimethylisoxazol-4-yl)-1-(4-methoxyphenyl)-3-methyl-1H-pyrazole-4-carbonitrile (11 mg, 0.037 mmol) and stirred at 130° C. for 30 min in the microwave. EtOAc and brine were added and the phases were separated. Purification using preparative HPLC gave E1 5-(3,5-dimethylisoxazol-4-yl)-N′-hydroxy-1-(4-hydroxyphenyl)-3-methyl-1H-pyrazole-4-carboximidamide (2.52 mg, 7.71 μmol, 21%) ES/MS m/z: 328.19 (M+H), 326.22 (M−H); 1H NMR (acetone-d6, 500 MHz): 7.10 m 2H, 6.84 m 2H, 2.36 s 3H, 2.10 s 3H, 1.89 s 3H. Starting material 5-(3,5-dimethylisoxazol-4-yl)-1-(4-hydroxyphenyl)-3-methyl-1H-pyrazole-4-carbonitrile was recovered (0.99 mg, 3.36 μmol) as well as E2 5-(3,5-dimethylisoxazol-4-yl)-1-(4-hydroxyphenyl)-3-methyl-1H-pyrazole-4-carboxamide (3.22 mg, 0.01 mmol) ES/MS m/z: 313.17 (M+H), 311.22 (M−H); 1H NMR (acetone-d6, 500 MHz): 7.10 m 2H, 6.85 m 2H, 2.47 s 3H, 2.12 s 3H, 1.95 s 3H. Identification of Example 6 by 1H-NMR showed that the oxime product was a single isomer, but did not confirm whether the (E) or (Z) oxime isomer had been obtained.

Workup

  1. filtrationthe mixture was filtered
  2. customdegassed (N2)
  3. customthe phases were separated
  4. customPurification

Sources & evidence

ORD record
ord-6f5cb40427fc4351972351c9ed0951d9
Source dataset
uspto-grants-2014_12
Patent number
US08921402B2

Reaction notes

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