Ethyl bromoacetate → ethyl 2-(1-oxo-6-vinylphthalazin-2(1H)-yl)acetate

HRID 1502990Notes

Reaction equation

HRID 1502990 reaction equation
[CH:1]([C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][CH:12]=1)[C:9](=[O:13])[NH:8][N:7]=[CH:6]2)=[CH2:2].C([O-])([O-])=O.[Cs+].[Cs+].Br[CH2:21][C:22]([O:24][CH2:25][CH3:26])=[O:23]>CN(C=O)C>[O:13]=[C:9]1[C:10]2[C:5](=[CH:4][C:3]([CH:1]=[CH2:2])=[CH:12][CH:11]=2)[CH:6]=[N:7][N:8]1[CH2:21][C:22]([O:24][CH2:25][CH3:26])=[O:23]

Participants

5

Reactant 3

HCID 7748Ethyl bromoacetateHCID 10796Cesium carbonateHCID 866751746-vinylphthalazine-1(2H)-one

Product 1

HCID 86675173ethyl 2-(1-oxo-6-vinylphthalazin-2(1H)-yl)acetateYield 45.4%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a stirred solution of 6-vinylphthalazine-1(2H)-one (0.5 g, 2.90 mmol) in DMF (5.0 mL) was added Cs2CO3 (0.94 g, 2.90 mmol) and the reaction was stirred for 10 min Ethyl bromoacetate (0.48 g, 2.90 mmol) was added to the reaction mixture at ambient temperature and the reaction was stirred for 8 h at ambient temperature. The reaction mixture was diluted and extracted with ethyl acetate, and the ethyl acetate layer was washed with water and brine solution (2×). The separated ethyl acetate layer was dried over anhydrous Na2SO4 and concentrated under reduced pressure to afford crude product. The crude compound was purified by column chromatography (SiO2, 100-200 mesh; 25% ethyl acetate/petroleum ether) to afford the title compound as a brown solid (0.34 g, 45%): 1H NMR (400 MHz, DMSO-d6) δ 8.45 (m, 1H), 8.24 (m, 1H), 8.04 (m, 2H), 7.01 (m, 1H), 6.17 (d, J=2.1 Hz, 1H), 5.56 (d, J=10.8 Hz, 1H), 4.92 (s, 2H), 4.19 (m, 2H), 1.23 (m, 3H). ESIMS m/z 259.10 ([M+H]+); IR (thin film) 1750, 1660 cm−1.

Workup

  1. additionwas added to the reaction mixture at ambient temperature
  2. additionThe reaction mixture was diluted
  3. extractionextracted with ethyl acetate
  4. washthe ethyl acetate layer was washed with water and brine solution (2×)
  5. dry with materialThe separated ethyl acetate layer was dried over anhydrous Na2SO4
  6. concentrationconcentrated under reduced pressure
  7. customto afford crude product
  8. customThe crude compound was purified by column chromatography (SiO2, 100-200 mesh; 25% ethyl acetate/petroleum ether)

Sources & evidence

ORD record
ord-16c21aefd16640ac8483568a469107f9
Source dataset
uspto-grants-2015_12
Patent number
US09211281B2

Reaction notes

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