Sodium Hydroxide → 3-Methyl-1-(2-methylphenyl)-1H-pyrazol-5-amine

HRID 915565Notes

Reaction equation

HRID 915565 reaction equation
[CH3:1]/[C:2](/N)=[CH:3]\[C:4]#[N:5].Cl.[CH3:8][C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][C:10]=1[NH:15][NH2:16].[OH-].[Na+]>Cl>[CH3:1][C:2]1[CH:3]=[C:4]([NH2:5])[N:15]([C:10]2[CH:11]=[CH:12][CH:13]=[CH:14][C:9]=2[CH3:8])[N:16]=1

Participants

5

Reactant 3

HCID 14798Sodium HydroxideHCID 71554o-Tolylhydrazinium(1+) chlorideHCID 53247203-Aminocrotonitrile

Product 1

HCID 7756883-Methyl-1-(2-methylphenyl)-1H-pyrazol-5-amineYield 91.8%

Reagents, catalysts & solvents 1

HCID 313Hydrochloric AcidSolvent

Conditions

Temperature
100 °C

Procedure

3-Aminocrotonitrile (2.00 g, 24.4 mmol) was added to a stirred solution of (2-methylphenyl)hydrazine hydrochloride (3.67 g, 23.1 mmol) in 1 M hydrochloric acid (20 mL). The reaction was heated (100° C.) for 18 h and then cooled to rt. The solution was adjusted to pH>12 using 1 M aqueous sodium hydroxide. The mixture was extracted with dichloromethane (3×20 mL), and then the combined organic extracts were washed with brine, dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo. Flash chromatography of the residue over silica gel using 25-50% ethyl acetate/hexane afforded 3-methyl-1-(2-methylphenyl)-1H-pyrazol-5-amine (3.97 g, 87%) as an orange oil. 1H NMR (300 MHz, acetone-d6) δ 7.29 (m, 4H), 5.32 (s, 1H), 2.12 (s, 3H), 2.08 (s, 3H); ES-MS m/z 188.2 (MH+), HPLC RT (min) 0.79.

Workup

  1. temperaturecooled to rt
  2. extractionThe mixture was extracted with dichloromethane (3×20 mL)
  3. washthe combined organic extracts were washed with brine
  4. dry with materialdried over anhydrous magnesium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-d057fb941b1848e99f106969aa5ffb9c
Source dataset
uspto-grants-2007_09
Patent number
US07265144B2

Reaction notes

Loading…