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

HRID 1595909Notes

Reaction equation

HRID 1595909 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) δ 6.64 (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-138ea9056024408ea34dba286022f6d1
Source dataset
uspto-grants-2001_09
Patent number
US06288120B1

Reaction notes

Loading…