Methanol → HCID 136341437, compound

HRID 525868Notes

Reaction equation

HRID 525868 reaction equation
[CH2:1]([N:3]1[C:12]2[C:7](=[CH:8][C:9]3[O:15]C[O:13][C:10]=3[CH:11]=2)[C:6](=[O:16])[C:5]([C:17]([OH:19])=[O:18])=[N:4]1)[CH3:2].B(Br)(Br)Br.[CH3:24]O>ClCCl>[CH2:1]([N:3]1[C:12]2[C:7](=[CH:8][C:9]([OH:15])=[C:10]([OH:13])[CH:11]=2)[C:6](=[O:16])[C:5]([C:17]([O:19][CH3:24])=[O:18])=[N:4]1)[CH3:2]

Participants

5

Reactant 3

HCID 887MethanolHCID 2762CinoxacinHCID 25134Boron tribromide

Product 1

HCID 136341437HCID 136341437, compoundYield 74.5%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Conditions

Temperature
-30 °C

Procedure

To a suspension of 1-ethyl-4-oxo-1,4-dihydro-[1,3]dioxolo[4,5-g]cinnoline-3-carboxylic acid (12.6 g, 48.1 mmol) in dichloromethane (DCM) (50 mL) stirred under nitrogen at −30° C. was added dropwise a solution of boron tribromide (168 mL, 168 mmol) in dichloromethane (140 mL). The white suspension turned yellowish. The mixture was kept at −30° C. for 1 h and then allowed to warm up to room temperature, and stirred for 40 h. The reaction mixture was again cooled to −30° C., methanol (100 mL) was added, and the resulting mixture was stirred at room temperature over the weekend. The organic solvents were partially removed to afford a light yellow suspension. The solid was collected by filtration and washed with dichloromethane (20 mL). The filtrate was concentrated again to provide more yellow solids that was collected and washed by dichloromethane (20 mL). The solids were combined to afford methyl 1-ethyl-6,7-dihydroxy-4-oxo-1,4-dihydrocinnoline-3-carboxylate (11 g, 35.8 mmol, 74.5% yield). LCMS: (M+H)+: 265.0

Workup

  1. temperatureto warm up to room temperature
  2. stirringstirred for 40 h
  3. temperatureThe reaction mixture was again cooled to −30° C.
  4. stirringthe resulting mixture was stirred at room temperature over the weekend
  5. customThe organic solvents were partially removed
  6. customto afford a light yellow suspension
  7. filtrationThe solid was collected by filtration
  8. washwashed with dichloromethane (20 mL)
  9. concentrationThe filtrate was concentrated again
  10. customto provide more yellow solids that
  11. customwas collected
  12. washwashed by dichloromethane (20 mL)

Sources & evidence

ORD record
ord-5ea701f4f60340e9a5119d5a420c9698
Source dataset
uspto-grants-2016_05
Patent number
US09340556B2

Reaction notes

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