N-bromobutanimide → 5-bromomethyl-1-tert-butyl-1H-pyrazole-4-carboxylic acid methyl ester

HRID 12869

反応式

HRID 12869 の反応式
[CH3:1][O:2][C:3]([C:5]1[CH:6]=[N:7][N:8]([C:11]([CH3:14])([CH3:13])[CH3:12])[C:9]=1[CH3:10])=[O:4].[Br:15]N1C(=O)CCC1=O.[Al]>C(Cl)(Cl)(Cl)Cl>[CH3:1][O:2][C:3]([C:5]1[CH:6]=[N:7][N:8]([C:11]([CH3:14])([CH3:13])[CH3:12])[C:9]=1[CH2:10][Br:15])=[O:4]

参加物

5

反応物 3

HCID 67184N-bromobutanimideHCID 5359268AluminumHCID 50853230Methyl 1-tert-butyl-5-methyl-1H-pyrazole-4-carboxylate

生成物 1

HCID 670210095-bromomethyl-1-tert-butyl-1H-pyrazole-4-carboxylic acid methyl ester収率 95.2%

試薬・触媒・溶媒 1

HCID 5943Carbon Tetrachloride溶媒

実験手順

A solution of 1-tert-butyl-5-methyl-1H-pyrazole-4-carboxylic acid methyl ester (3.38 g, 17.22 mmol) (as described in Example 54, Step 2) in carbon tetrachloride (12.2 mL, 1.41M) at 25° C. was treated with N-bromosuccinimide (3.10 g, 17.41 mmol). The reaction flask was fitted with a reflux condenser. The set-up was wrapped with aluminum foil and was then illuminated with a 250 Watt sun lamp for 3 h. At this time, the reaction was filtered and was rinsed with carbon tetrachloride. The filtrate was transferred to a separatory funnel and was washed with water (1×50 mL) and a saturated aqueous sodium chloride solution (1×50 mL). The organics were dried over magnesium sulfate, filtered, rinsed with carbon tetrachloride and concentrated in vacuo to a light yellow oil. ISCO CombiFlash chromatography (120 g, 0-10% ethyl acetate/hexanes) afforded 5-bromomethyl-1-tert-butyl-1H-pyrazole-4-carboxylic acid methyl ester (4.51 g, 95%) as a clear oil. The material was used without further purification.

後処理

  1. customThe reaction flask was fitted with a reflux condenser
  2. customwas then illuminated with a 250 Watt sun lamp for 3 h
  3. filtrationAt this time, the reaction was filtered
  4. washwas rinsed with carbon tetrachloride
  5. customThe filtrate was transferred to a separatory funnel
  6. washwas washed with water (1×50 mL)
  7. dry with materialThe organics were dried over magnesium sulfate
  8. filtrationfiltered
  9. washrinsed with carbon tetrachloride
  10. concentrationconcentrated in vacuo to a light yellow oil

出典と根拠

ORDレコード
ord-704fa6d8f15e4577859d908484cd061c
出典データセット
uspto-grants-2010_06
特許番号
US07728029B2

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