Lawesson's reagent → 3-Methyl-1-(2-pyridinyl)-1,9-dihydro-4H-pyrazolo[3,4-b]quinolin-4-thione

HRID 498021Notes

Reaction equation

HRID 498021 reaction equation
[CH3:1][C:2]1[C:14]2[C:13](=O)[C:12]3[C:7](=[CH:8][CH:9]=[CH:10][CH:11]=3)[NH:6][C:5]=2[N:4]([C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][N:17]=2)[N:3]=1.COC1C=CC(P2(SP(C3C=CC(OC)=CC=3)(=S)S2)=[S:31])=CC=1>C1(C)C=CC=CC=1>[CH3:1][C:2]1[C:14]2[C:13](=[S:31])[C:12]3[C:7](=[CH:8][CH:9]=[CH:10][CH:11]=3)[NH:6][C:5]=2[N:4]([C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][N:17]=2)[N:3]=1

Participants

4

Reactant 2

HCID 87949Lawesson's reagentHCID 1358480443-Methyl-1-(2-pyridinyl)-1,9-dihydro-4H-pyrazolo[3,4-b]quinolin-4-one

Product 1

HCID 1358480753-Methyl-1-(2-pyridinyl)-1,9-dihydro-4H-pyrazolo[3,4-b]quinolin-4-thioneYield 145.1%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A solution of 3-methyl-1-(2-pyridinyl)-1,9-dihydro-4H-pyrazolo[3,4-b]quinolin-4-one (13.94 g, 50.5 mmol) and Lawesson's Reagent (12.5 g, 30.9 mmol) in toluene (750 mL) was heated under reflux for 1 hour. The reaction solution was cooled to room temperature, and the resulting crude crystals were collected by filtration. The crystals were recrystallized from ethyl acetate to give the title compound (13.11 g, 89% yield).

Workup

  1. temperatureunder reflux for 1 hour
  2. filtrationthe resulting crude crystals were collected by filtration
  3. customThe crystals were recrystallized from ethyl acetate

Sources & evidence

ORD record
ord-b85d0fe8af4e4c22b9fa4a995c21c8e1
Source dataset
uspto-grants-2005_09
Patent number
US06949648B2

Reaction notes

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