Hydrazine → 5-[3-(tert-Butyl-dimethyl-silanyloxy)-propyl]-1H-pyrazole-3-carboxylic Acid Ethyl Ester

HRID 1699079Notes

Reaction equation

HRID 1699079 reaction equation
[CH2:1]([O:3][C:4](=[O:21])[C:5](=O)[CH2:6][C:7](=O)[CH2:8][CH2:9][CH2:10][O:11][Si:12]([C:15]([CH3:18])([CH3:17])[CH3:16])([CH3:14])[CH3:13])[CH3:2].[NH2:22][NH2:23]>CCO>[CH2:1]([O:3][C:4]([C:5]1[CH:6]=[C:7]([CH2:8][CH2:9][CH2:10][O:11][Si:12]([C:15]([CH3:18])([CH3:17])[CH3:16])([CH3:14])[CH3:13])[NH:23][N:22]=1)=[O:21])[CH3:2]

Participants

4

Reactant 2

HCID 9321HydrazineHCID 54073086Ethyl 7-[(tert-butyldimethylsilyl)oxy]-2,4-dioxoheptanoate

Product 1

HCID 539527935-[3-(tert-Butyl-dimethyl-silanyloxy)-propyl]-1H-pyrazole-3-carboxylic Acid Ethyl EsterYield 2.1%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of 7-(tert-butyl-dimethyl-silanyloxy)-2,4-dioxo-heptanoic acid ethyl ester (1.627 g, 51.4 mmol) and hydrazine (17 mL, 55 mmol) in EtOH was heated at reflux for 6 h. The reaction was concentrated in vacuo. Purification by flash chromatography (6:4 hexanes:EtOAc) provided the title compound (333 mg). 1H NMR (400 MHz, CDCl3) δ6.64 (s, 1H), 4.37 (q, 2H), 3.67 (t, 2H), 2.85 (t, 2H), 1.88 (m, 2H), 1.38 (t, 3H), 0.88 (s, 9H), 0.05 (s, 6H); MS 313 (M+1).

Workup

  1. temperatureat reflux for 6 h
  2. concentrationThe reaction was concentrated in vacuo
  3. customPurification by flash chromatography (6:4 hexanes:EtOAc)

Sources & evidence

ORD record
ord-73024e582566434da2eddd5ce8a32e4c
Source dataset
uspto-grants-2002_02
Patent number
US06344485B1

Reaction notes

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