Hydrochloric Acid → 6,7-Dichloro-2,3-dimethoxyquinoxaline-5-boronic acid

HRID 842664ノート

反応式

HRID 842664 の反応式
O1CCCC1.C([N-]C(C)C)(C)C.[Li+].[Cl:14][C:15]1[CH:16]=[C:17]2[C:22](=[CH:23][C:24]=1[Cl:25])[N:21]=[C:20]([O:26][CH3:27])[C:19]([O:28][CH3:29])=[N:18]2.[B:30](OC)([O:33]C)[O:31]C.Cl>O1CCCC1.O>[Cl:25][C:24]1[C:15]([Cl:14])=[CH:16][C:17]2[N:18]=[C:19]([O:28][CH3:29])[C:20]([O:26][CH3:27])=[N:21][C:22]=2[C:23]=1[B:30]([OH:33])[OH:31]

参加物

7

反応物 4

HCID 313Hydrochloric AcidHCID 8470Trimethyl borateHCID 10997623Lithium diisopropylamide mono(tetrahydrofuran)HCID 120471106,7-Dichloro-2,3-dimethoxyquinoxaline

生成物 1

HCID 120471116,7-Dichloro-2,3-dimethoxyquinoxaline-5-boronic acid収率 26.1%

試薬・触媒・溶媒 2

HCID 962Water溶媒HCID 8028Tetrahydrofuran溶媒

実験手順

Lithium diisopropylamide mono(tetrahydrofuran) (1.5M in cyclohexane, 6.18 mL, 9.26 mmol) was added to a stirred suspension of 6,7-dichloro-2,3-dimethoxyquinoxaline (Preparation 1, 2.0 g, 7.72 mmol) in dry tetrahydrofuran (150 mL) at −78° C., under nitrogen. After 1 hour at −78° C., trimethyl borate (1.47 mL, 2.0 g, 19.3 mmol) was added. The solution was stirred for a further 1 hour and then left to reach room temperature over 18 hours. Water (50 mL) was added, the solution was acidified to pH 1 with 2M aqueous hydrochloric acid solution and extracted with dichloromethane (3×150 mL). The combined organic extracts were dried (MgSO4) and concentrated under reduced pressure. The residue was purified by flash chromatography on silica gel, by gradient elution using dichloromethane:methanol (100:0 changing to 99:1, by volume) as the eluent to afford 6,7-dichloro-2,3-dimethoxyquinoxaline-5-boronic acid (0.610 g, 26%) as a light brown solid.

後処理

  1. waitleft
  2. waitto reach room temperature over 18 hours
  3. extractionextracted with dichloromethane (3×150 mL)
  4. dry with materialThe combined organic extracts were dried (MgSO4)
  5. concentrationconcentrated under reduced pressure
  6. customThe residue was purified by flash chromatography on silica gel, by gradient elution

出典と根拠

ORDレコード
ord-e14c38ab15434c38a0149fee9cdf3a55
出典データセット
uspto-grants-2002_04
特許番号
US06376490B1

反応ノート

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