1,4-Dibromobutane → HCID 57242902、化合物

HRID 650143

反応式

HRID 650143 の反応式
C([Li])CCC.[CH2:6]([O:8][C:9]1[C@H:10]([CH:18]([CH3:20])[CH3:19])[N:11]=[C:12]([O:15][CH2:16][CH3:17])[CH2:13][N:14]=1)[CH3:7].[Br:21][CH2:22][CH2:23][CH2:24][CH2:25]Br>O1CCCC1.C(OCC)C>[CH2:6]([O:8][C:9]1[C@H:10]([CH:18]([CH3:20])[CH3:19])[N:11]=[C:12]([O:15][CH2:16][CH3:17])[C@@H:13]([CH2:25][CH2:24][CH2:23][CH2:22][Br:21])[N:14]=1)[CH3:7]

参加物

6

反応物 3

HCID 80561,4-DibromobutaneHCID 11020211(S)-2,5-Dihydro-3,6-diethoxy-2-isopropylpyrazineHCID 178418339Butyllithium

生成物 1

HCID 57242902HCID 57242902、化合物収率 57%

試薬・触媒・溶媒 2

HCID 3283Diethyl Ether溶媒HCID 8028Tetrahydrofuran溶媒

実験手順

n-butyllithium (13.3 mL of a 1.6 M solution in hexanes,21.3 mmol) was added to a solution of (2S)-2,5-dihydro-3,6-diethoxy-2-isopropyl pyrazine (Schöllkopf reagent)(4.30 g, 20.3 mmol) in tetrahydrofuran (THF) over the course of five minutes. The solution was maintained at −78° C. for 15 minutes after which 1,4-dibromobutane (9.75 mL, 81.2 mmol) was added in a single portion. After 2.5 hours at −78° C. the reaction was allowed to warm to room temperature and diluted with diethyl ether (100 mL). The organic phase was washed with water (100 mL), brine (100 mL) and then dried with magnesium sulfate (MgSO4). Following filtration and concentration most of the residual 1,4-dibromobutane was removed under high vacuum. The remaining oil was purified by silica gel chromatography (2% ethyl acetate in hexanes) to provide 5 (3.7 g, 57%) as a colorless liquid;[α]25D−1.13° (c=4.5, CHCl3); IR (thin film) 2957, 1689, 1456, 1364, 1304, 1230, 1144, 1038 cm−1; 1H NMR(300 MHz, CDCl3) δ4.04-4.18 (m, 4H) 3.94-4.02 (m, 1H) 3.90 (t, J=3.9, 1H) 3.39 (t, J=6.9, 2H) 2.21-2.32 (m, 1H) 1.68-1.92 (m, 4H) 1.33-1.47 (m, 2H) 1.274 (t, J=7.2, 3H) 1.268 (t, J=7.2, 3H) 1.03 (d, J=6.9, 3H) 0.70 (d, J=6.9, 3H); 13C NMR (100.6 MHz, CDCl3) d 163.12, 163.05, 60.72, 60.48, 55.09, 33.60, 33.11, 32.66, 31.80, 23.22, 19.03, 16.6, 14.34, 14.31; Mass Spectrum (FAB+) 347.1 (MH+).

後処理

  1. additionwas added in a single portion
  2. washThe organic phase was washed with water (100 mL), brine (100 mL)
  3. dry with materialdried with magnesium sulfate (MgSO4)
  4. filtrationfiltration and concentration most of the residual 1,4-dibromobutane
  5. customwas removed under high vacuum
  6. customThe remaining oil was purified by silica gel chromatography (2% ethyl acetate in hexanes)

出典と根拠

ORDレコード
ord-6d166a1c760b4b7183b1146cfa41e80f
出典データセット
uspto-grants-2001_08
特許番号
US06271198B1

関連ノート

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