Methanol → 3-(Methoxycarbonyl)pyrazine-2-carboxylic acid

HRID 853659

反応式

HRID 853659 の反応式
[N:1]1[CH:6]=[CH:5][N:4]=[C:3]([C:7]([OH:9])=[O:8])[C:2]=1[C:10]([OH:12])=[O:11].OS(O)(=O)=O.[CH3:18]O>>[CH3:18][O:11][C:10]([C:2]1[C:3]([C:7]([OH:9])=[O:8])=[N:4][CH:5]=[CH:6][N:1]=1)=[O:12]

参加物

4

反応物 3

HCID 887MethanolHCID 1118Sulfuric AcidHCID 666282,3-Pyrazinedicarboxylic acid

生成物 1

HCID 152073463-(Methoxycarbonyl)pyrazine-2-carboxylic acid収率 47%

反応条件

温度
75 °C

実験手順

To a mixture of pyrazine-2,3-dicarboxylic acid (20 g, 119 mmol, 1 equiv.) was added MeOH (80 mL) followed by dropwise addition of concentrated H2SO4 (36 mL, 680 mmol, 5.7 equiv.) over 45 minutes. This method is similar to that that cited for a different substrate (J. Am. Chem. Soc., 73, 1951, 5614-5616). The reaction was heated at 75° C. for 16 hours and then cooled and quenched with water (200 mL). It was extracted with EtOAc (4×60 mL) and the organic layer washed several times with water (3×50 ml), saturated NaHCO3 (50 ml), brine solution (50 mL). It was dried over Na2SO4, filtered and concentrated in vacuo to yield pyrazine-2,3-dicarboxylic acid methyl ester 241 as a brown solid (47%, 10.97 g, 55.9 mmol). 1H NMR (300 MHz) CDCl3 δ 8.79 (d, J=2.7 Hz, 2 H), 4.05 (s, 3 H), 4.04 (s, 3 H). TLC Rf: 0.7 ethyl acetate/methanol (9/1)

後処理

  1. temperaturecooled
  2. customquenched with water (200 mL)
  3. extractionIt was extracted with EtOAc (4×60 mL)
  4. washthe organic layer washed several times with water (3×50 ml), saturated NaHCO3 (50 ml), brine solution (50 mL)
  5. dry with materialIt was dried over Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo

出典と根拠

ORDレコード
ord-78a8bc3b12aa4350b2208e818ed7040e
出典データセット
uspto-grants-2007_08
特許番号
US07253180B2

関連ノート

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