Water → Phenyl 5-ethylpyrido[3,4-b]pyrazine-6(5H)-carboxylate

HRID 132865Notes

Reaction equation

HRID 132865 reaction equation
Cl[C:2]([O:4][C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1)=[O:3].[N:11]1[CH:16]=[CH:15][N:14]=[C:13]2[CH:17]=[N:18][CH:19]=[CH:20][C:12]=12.[CH2:21]([Mg]Br)[CH3:22].O>O1CCCC1>[CH2:21]([CH:17]1[C:13]2=[N:14][CH:15]=[CH:16][N:11]=[C:12]2[CH:20]=[CH:19][N:18]1[C:2]([O:4][C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1)=[O:3])[CH3:22]

Participants

6

Reactant 4

HCID 962WaterHCID 15891Phenyl chloroformateHCID 638007Pyrido[3,4-b]pyrazineHCID 178418443HCID 178418443, compound

Product 1

HCID 69182531Phenyl 5-ethylpyrido[3,4-b]pyrazine-6(5H)-carboxylate

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
0 °C

Procedure

A solution of phenyl chloroformate (0.200 mL, 250 mg, 1.59 mmol) in tetrahydrofuran (3.5 mL) was added over 20 min to a solution of 200 mg (1.53 mmol) of pyrido[3,4-b]pyrazine (prepared according to the procedure of F. F. Duarte and F. D. Popp, J. Heterocyclic Chem., 31: 819-823 (1994)) in tetrahydrofuran (7.5 mL) cooled in a −25° C. bath. After 10 min, ethylmagnesium bromide (1.0M in tetrahydrofuran, 1.54 mL, 1.54 mmol) was added over 10 min. The mixture was allowed to warm to 0° C. over 1 h. After an additional 30 min at 0° C., water (20 mL) was added and the mixture was extracted with ethyl acetate (50 mL). The organic layer was washed with saturated sodium bicarbonate solution (10 mL) followed by saturated aqueous brine (10 mL). The aqueous layers were extracted in succession with ethyl acetate (25 mL) and the organic layers were dried over sodium sulfate, decanted, and evaporated. Purification by flash chromatography (silica gel, 4-5% ethyl acetate in 1:1 hexanes/dichloromethane) gave the title compound as a colorless syrup. LC/MS 282 (M+1).

Workup

  1. customprepared
  2. waitAfter an additional 30 min at 0° C.
  3. extractionthe mixture was extracted with ethyl acetate (50 mL)
  4. washThe organic layer was washed with saturated sodium bicarbonate solution (10 mL)
  5. extractionThe aqueous layers were extracted in succession with ethyl acetate (25 mL)
  6. dry with materialthe organic layers were dried over sodium sulfate
  7. customdecanted
  8. customevaporated
  9. customPurification by flash chromatography (silica gel, 4-5% ethyl acetate in 1:1 hexanes/dichloromethane)

Sources & evidence

ORD record
ord-0acb30771d6a4f0f8e6649d6562b2a3b
Source dataset
uspto-grants-2008_06
Patent number
US07388019B2

Reaction notes

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