Hydrochloric Acid → Methyl 2-(4-acetyl-5-methyl-1H-pyrazol-1-yl)acetate

HRID 2425546ノート

反応式

HRID 2425546 の反応式
C(O[CH:4]=[C:5]([C:9](=[O:11])[CH3:10])[C:6](=O)[CH3:7])C.Cl.[NH:13]([CH2:15][C:16]([O:18][CH2:19]C)=[O:17])[NH2:14].Cl>CO>[C:9]([C:5]1[CH:4]=[N:14][N:13]([CH2:15][C:16]([O:18][CH3:19])=[O:17])[C:6]=1[CH3:7])(=[O:11])[CH3:10]

参加物

5

反応物 3

HCID 313Hydrochloric AcidHCID 2404183-(Ethoxymethylene)pentane-2,4-dioneHCID 11593468Acetic acid, 2-hydrazinyl-, ethyl ester, hydrochloride (1:1)

生成物 1

HCID 67181907Methyl 2-(4-acetyl-5-methyl-1H-pyrazol-1-yl)acetate収率 51%

試薬・触媒・溶媒 1

HCID 887Methanol溶媒2 回

実験手順

To a solution of 3-(ethoxymethylene)pentane-2,4-dione (Perkin 1. 2000, 1455-1460, 1.95 g, 12.5 mmol) in MeOH (33 mL) was added a solution of ethyl hydrazinoacetate hydrochloride (2.09 g, 13.5 mmol) and conc.HCl (2.6 ml) in MeOH (10 ml) (pre-cooled to 0° C.) dropwise at −15° C. The resulting mixture was then stirred for 24 hours at room temperature. After removal of the solvent at room temperature, the residue was basified with 2N NaOH aq, and the aqueous layer was extracted several times with EtOAc. The combined organic extracts were dried over Na2SO4, and concentrated in vacuo. The aqueous layer was acidified to pH 1 with 2N HCl aq. and extracted with EtOAc 6 times. The combined organic extracts were dried over Na2SO4, and concentrated in vacuo to give the crude 2-(4-acetyl-5-methyl-1H-pyrazol-1-yl)acetic acid as a mixture of regioisomers (1.17 g, <51% yield). 1H NMR (300 MHz, DMSO-d6) δ 2.37 (3H, s), 2.43 (3H, s), 4.99 (2H, s), 7.81 (1H, s), 13.2 (1H, brs).

後処理

  1. customdropwise at −15° C
  2. customAfter removal of the solvent at room temperature
  3. extractionthe aqueous layer was extracted several times with EtOAc
  4. dry with materialThe combined organic extracts were dried over Na2SO4
  5. concentrationconcentrated in vacuo
  6. extractionextracted with EtOAc 6 times
  7. dry with materialThe combined organic extracts were dried over Na2SO4
  8. concentrationconcentrated in vacuo

出典と根拠

ORDレコード
ord-d43b84bb2a0241498bdceb2d977672b4
出典データセット
uspto-grants-2011_06
特許番号
US07964732B2

反応ノート

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