3-Chloro-2-hydrazinylpyridine → Ethyl 1-(3-chloropyridin-2-yl)-5-hydroxy-3-(hydroxymethyl)-4,5-dihydro-1H-pyrazole-5-carboxylate

HRID 1515371Notes

Reaction equation

HRID 1515371 reaction equation
CC1(C)O/[C:5](=[CH:7]/[C:8](=[O:14])[C:9]([O:11][CH2:12][CH3:13])=[O:10])/[CH2:4][O:3]1.[NH:16]([C:18]1[C:23]([Cl:24])=[CH:22][CH:21]=[CH:20][N:19]=1)[NH2:17]>C(O)C>[Cl:24][C:23]1[C:18]([N:16]2[C:8]([OH:14])([C:9]([O:11][CH2:12][CH3:13])=[O:10])[CH2:7][C:5]([CH2:4][OH:3])=[N:17]2)=[N:19][CH:20]=[CH:21][CH:22]=1

Participants

4

Reactant 2

HCID 5561003-Chloro-2-hydrazinylpyridineHCID 67235684ethyl (3E)-3-(2,2-dimethyl-1,3-dioxolan-4-ylidene)-2-oxopropanoate

Product 1

HCID 58320694Ethyl 1-(3-chloropyridin-2-yl)-5-hydroxy-3-(hydroxymethyl)-4,5-dihydro-1H-pyrazole-5-carboxylateYield 120.1%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

The mixture of ethyl (3E)-3-(2,2-dimethyl-1,3-dioxolan-4-ylidene)-2-oxopropanoate (21.4 g, 0.1 mol) and 2-hydrazino-3-chloropyridine (21.4 g, 0.15 mol) in 150 ml of ethanol was stirred for 8 hours at RT. Ethanol was removed in vacuo and the residue was taken up in 200 ml of methyl tert-butyl ethyl. The organic phase was washed three times with in each case 50 ml of 1% HCl and concentrated by evaporation. This gave 36 g (86% yield) of the product as a viscous oil with a purity (HPLC) of 97%.

Workup

  1. customEthanol was removed in vacuo
  2. washThe organic phase was washed three times with in each case 50 ml of 1% HCl
  3. concentrationconcentrated by evaporation

Sources & evidence

ORD record
ord-582828fe63ce42618c2c9ecbb0972315
Source dataset
uspto-grants-2012_07
Patent number
US08222435B2

Reaction notes

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