Acetic Acid → 4-Thiophen-2-yl-2h-pyrazol-3-ylamine

HRID 1844333Notes

Reaction equation

HRID 1844333 reaction equation
O.[NH2:2][NH2:3].C(O)(=O)C.O=[CH:9][CH:10]([C:13]1[S:14][CH:15]=[CH:16][CH:17]=1)[C:11]#[N:12]>C(O)C>[S:14]1[CH:15]=[CH:16][CH:17]=[C:13]1[C:10]1[CH:9]=[N:3][NH:2][C:11]=1[NH2:12]

Participants

5

Reactant 3

HCID 176Acetic AcidHCID 24654Hydrazine hydrate (1:1)HCID 10464503α-Formyl-2-thiopheneacetonitrile

Product 1

HCID 8189424-Thiophen-2-yl-2h-pyrazol-3-ylamine

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Hydrazine hydrate [7803-57-8] (4.8 mL, 99.0 mmol) then acetic acid [64-19-7] (5.6 mL, 97.8 mmol) were added to a solution of 3-oxo-2-thiophen-2-yl-propionitrile (7.4 g, 49.0 mmol) in ethanol (100 mL). The solution was then heated to reflux for 2 h. The cooled reaction was evaporated to dryness and the resultant solid triturated in water. Product was isolated by filtration, washed with water, and dried to provide 4-thiophen-2-yl-2H-pyrazol-3-ylamine as 7.1 g of fine off white powder, mp. 183-1840° C. 1H NMR (400 MHz, DMSO-d6) δ ppm 2.51 (s, 1 H) 7.01-7.10 (m, 2 H) 7.27 (dd, J=5.05, 1.01 Hz, 1 H). 13C NMR (100 MHz, DMSO-d6) δ ppm 121.07, 121.47, 127.58, 135.85. LRMS (ESI) m/z 166.0 [(M+H)]+, calc'd for C7H7N3S: 165.22.

Workup

  1. temperatureThe solution was then heated
  2. temperatureto reflux for 2 h
  3. customThe cooled reaction
  4. customwas evaporated to dryness
  5. customthe resultant solid triturated in water
  6. customProduct was isolated by filtration
  7. washwashed with water
  8. customdried

Sources & evidence

ORD record
ord-76656b6fc8704fac99b63cb2a1e34c60
Source dataset
uspto-grants-2015_02
Patent number
US08946415B2

Reaction notes

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