1,2-Dimethoxyethane → Ethyl 8-[(2-fluorobenzyl)oxy]-2-methylimidazo[1,2-a]pyridine-3-carboxylate

HRID 544451Notes

Reaction equation

HRID 544451 reaction equation
[NH2:1][C:2]1[C:7]([O:8][CH2:9][C:10]2[CH:15]=[CH:14][CH:13]=[CH:12][C:11]=2[F:16])=[CH:6][CH:5]=[CH:4][N:3]=1.Cl[CH:18]([C:24]([CH3:26])=O)[C:19]([O:21][CH2:22][CH3:23])=[O:20].C(=O)(O)[O-].[Na+].C(COC)OC>CCCCCC>[CH2:22]([O:21][C:19]([C:18]1[N:3]2[CH:4]=[CH:5][CH:6]=[C:7]([O:8][CH2:9][C:10]3[CH:15]=[CH:14][CH:13]=[CH:12][C:11]=3[F:16])[C:2]2=[N:1][C:24]=1[CH3:26])=[O:20])[CH3:23]

Participants

6

Reactant 4

HCID 80711,2-DimethoxyethaneHCID 11858Ethyl 2-chloroacetoacetateHCID 516892Sodium BicarbonateHCID 102424912-Amino-3-(2-fluorobenzyloxy)pyridine

Product 1

HCID 53732806Ethyl 8-[(2-fluorobenzyl)oxy]-2-methylimidazo[1,2-a]pyridine-3-carboxylate

Reagents, catalysts & solvents 1

HCID 8058HexaneSolvent

Procedure

A mixture of 25.0 g of 2-amino-3-(2-fluorobenzyloxy)pyridine, 20.5 g ethyl 2-chloroacetoacetate, 10.0 g of sodium bicarbonate and 250 ml dimethoxyethane was heated under reflux for 48 hrs. An additional 5.0 g ethyl 2-chloroacetonacetate was added and refluxed for another 24 hrs., followed by another 5.0 g and refluxed for a further 66 hrs. The mixture was cooled and suctionfiltered. The solids collected were washed with tetrahydrofuran, and the combined filtrate and washings were evaporated invacuo to leave a dark-colored oil. Hexane (200 ml) was added to the oil with vigorous stirring, and the resulting precipitate filtered off. To this solid was added (with vigorous stirring) acetonitrile (50 ml) and diisopropyl ether (200 ml) and stirring was continued for 0.5 hr. The suspended solid was filtered and crystallized from acetonitrile to give the desired ester.

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 48 hrs
  3. additionAn additional 5.0 g ethyl 2-chloroacetonacetate was added
  4. temperaturerefluxed for another 24 hrs
  5. temperaturerefluxed for a further 66 hrs
  6. temperatureThe mixture was cooled
  7. customThe solids collected
  8. washwere washed with tetrahydrofuran
  9. customthe combined filtrate and washings were evaporated invacuo
  10. customto leave a dark-colored oil
  11. filtrationthe resulting precipitate filtered off
  12. additionTo this solid was added (with vigorous stirring) acetonitrile (50 ml) and diisopropyl ether (200 ml)
  13. filtrationThe suspended solid was filtered
  14. customcrystallized from acetonitrile

Sources & evidence

ORD record
ord-9c2ee3ee29bd4d4fadde27d26aa4c138
Source dataset
uspto-grants-1984_05
Patent number
US04450164

Reaction notes

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