Hydrazine hydrate (1:1) → ethyl 5-(1,3-thiazol-2-yl)-1H-pyrazole-3-carboxylate

HRID 129836Notes

Reaction equation

HRID 129836 reaction equation
[CH2:1]([O:3][C:4](=[O:15])[C:5](=O)[CH2:6][C:7](=O)[C:8]1[S:9][CH:10]=[CH:11][N:12]=1)[CH3:2].O.[NH2:17][NH2:18]>C(O)C>[CH2:1]([O:3][C:4]([C:5]1[CH:6]=[C:7]([C:8]2[S:9][CH:10]=[CH:11][N:12]=2)[NH:18][N:17]=1)=[O:15])[CH3:2]

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 537614132,4-Dioxo-4-thiazol-2-yl-butyric acid ethyl ester

Product 1

HCID 19370588ethyl 5-(1,3-thiazol-2-yl)-1H-pyrazole-3-carboxylateYield 33.2%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 2,4-diketo-4-(thiazol-2-yl)butyric acid ethyl ester (9.88 g), hydrazine hydrate (1.74 g), and ethanol (25 ml) was refluxed for one hour, concentrated and the residue chromatographed (silica gel, EtOAc/Hex 1/2) to afford 2.58 g of 5-(thiazol-2-yl)pyrazole-3-carboxylic acid ethyl ester. NMR: 1.42 (t, 3H), 4.44 (q, 2H), 7.37 (s, 1H, 4-pyrazolyl H), 7.40, 7.75 (2d, 2H, thiazolyl H's).

Workup

  1. temperaturewas refluxed for one hour
  2. concentrationconcentrated
  3. customthe residue chromatographed (silica gel, EtOAc/Hex 1/2)

Sources & evidence

ORD record
ord-fc598eb4e5ef46e8b5f5ec041f2c0eaa
Source dataset
uspto-grants-1995_11
Patent number
US05470862

Reaction notes

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