Triethylamine → 6-(3,7-dimethylimidazo[1,2-a]pyridin-2-yl)-2-methyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine

HRID 1731360Notes

Reaction equation

HRID 1731360 reaction equation
[CH3:1][C:2]1[N:6]2[CH:7]=[CH:8][C:9]([CH3:11])=[CH:10][C:5]2=[N:4][C:3]=1[C:12]1[CH:17]=[CH:16][C:15]([OH:18])=[C:14]([NH2:19])[CH:13]=1.C(N(CC)CC)C.Br[CH:28]([CH3:32])[C:29](Br)=[O:30]>O1CCCC1>[CH3:1][C:2]1[N:6]2[CH:7]=[CH:8][C:9]([CH3:11])=[CH:10][C:5]2=[N:4][C:3]=1[C:12]1[CH:17]=[CH:16][C:15]2[O:18][CH:28]([CH3:32])[C:29](=[O:30])[NH:19][C:14]=2[CH:13]=1

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 79047Propanoyl bromide, 2-bromo-HCID 139224672-Amino-4-(3,7-dimethylimidazo[1,2-a]pyridin-2-yl)phenol

Product 1

HCID 202286656-(3,7-dimethylimidazo[1,2-a]pyridin-2-yl)-2-methyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazineYield 32.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of 3,7-dimethyl-2-(3-amino-4-hydroxyphenyl)imidazo[1,2-a]pyridine (1.27 g) and triethylamine (1.0 g) in tetrahydrofuran (100 ml) was added to 2-bromopropionyl bromide (1.3 g) at ambient temperature. The resultant mixture was stirred at ambient temperature for 2 hours and at 60° to 70° C. for 2 hours. The reaction mixture was evaporated under reduced pressure and the residue was dissolved in a mixture of ethyl acetate and water. The separated organic layer was washed with brine and dried over magnesium sulfate. The solvent was removed in vacuo and the residue was subjected to column chromatography on silica gel eluting with a mixture of chloroform and methanol (9:1). The fractions containing the desired compound were combined and evaporated in vacuo to afford a crystalline residue, which was recrystallized from ethyl acetate to give 6-(3,7-dimethylimidazo[1,2-a]pyridin-2-yl)-2-methyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine (0.5 g). mp. 254°-256° C.

Workup

  1. customThe reaction mixture was evaporated under reduced pressure
  2. dissolutionthe residue was dissolved in a mixture of ethyl acetate and water
  3. washThe separated organic layer was washed with brine
  4. dry with materialdried over magnesium sulfate
  5. customThe solvent was removed in vacuo
  6. additionthe residue was subjected to column chromatography on silica gel eluting with a mixture of chloroform and methanol (9:1)
  7. additionThe fractions containing the desired compound
  8. customevaporated in vacuo
  9. customto afford a crystalline residue, which
  10. customwas recrystallized from ethyl acetate

Sources & evidence

ORD record
ord-af67918ab0824fbab889061530614664
Source dataset
uspto-grants-1986_11
Patent number
US04621084

Reaction notes

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