Iodine → 2-fluoroquinoxaline

HRID 342889

반응식

HRID 342889 반응식
[N:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[N:4]=[CH:3][CH:2]=1.II.[F:13]F.C(=O)(O)[O-].[Na+]>S(S([O-])=O)([O-])(=O)=O.[Na+].[Na+]>[F:13][C:2]1[CH:3]=[N:4][C:5]2[C:10](=[CH:9][CH:8]=[CH:7][CH:6]=2)[N:1]=1

참가 물질

6

반응물 4

HCID 807IodineHCID 7045QuinoxalineHCID 24524Fluorine2회HCID 516892Sodium Bicarbonate

생성물 1

HCID 109425992-fluoroquinoxaline

시약·촉매·용매 1

HCID 656671Sodium Pyrosulfite용매

실험 절차

A solution containing quinoxaline (15.6 g), 120 mmol) and iodine (30.5 g, 120 mmol) in CF2ClCFCl2 (150 ml) was placed in a fluorination apparatus fitted with a drying tube filled with soda lime. Elemental fluorine (165 mmol) as a 10% mixture in nitrogen was then passed through the stirred solution using narrow bore PTFE tubing at ca. 40 ml/min. After the fluorine had been added the solution was poured into 10% aqueous sodium metabisulfite solution (300 ml), neutralised with sodium bicarbonate and continuously extracted with dichloromethane for 24 hours. The organic extracts were dried and evaporated to an oil (13.6 g). GC/MS analysis showed a 49% conversion of quinoxaline. The oil was purified by column chromatography on silica gel using dichloromethane as eluant to give pure 2-fluoroquinoxaline as a pale yellow oil (5.30 g, 62% based on 49% conversion); RF 0.53; δH (200 MHz; CDCl3 ; Me4Si) 7.7 ppm (2H, m), 7.9 (1H, m), 8.1 (1H, m), 8.67 (1H, d, JH,F 7.9, H-3); δF (250 MHZ; CDCl3 ; Me4Si) -75.1 ppm (s); δC (50.3 MHz, CDC13, Me4Si) 128.4 ppm (d, 4JC,F 1.6, C-8), 129.4 (s, C-7), 129.45 (s, C-6), 131.6 (s, C-5), 136.5 (d, 2JC,F 42.6, C-3), 139.72 (d, 3JC,F 10.9, C-8a), 141.52 (d 4JC,F 1.8, C-4a), 156.74 (d, 1JC-F 256.0, C-2); m/z (E1+) 148 (M+, 100), 129 (20), 121 (12), 103 (17), 76 (24), 50 (17); and 2,3-difluoroquinoxaline (0.27 g, 3%) as a pale yellow solid; RF 0.75; δH (400 MHz, CDCl3, Me4Si) 7.79 ppm (2H, m, Ar-H), 7.99 (2H, m, Ar-H); δC (50 MHz, CDCl3, Me4Si) 127.8 (s, C-8), 130.4 (s, C-7), 130.4 (s, C-7), 138.4 (d d, 3JC-F 5.4, C-4a), 146.1 (d d, 1JC-F 261.3,2JC-F 39.5, C-2); δF (235 MHz, CDCl3, CFCl3) -82.8 ppm (s); m/z (E1+) 166 (M+, 100%), 139 (11).

후처리

  1. customfitted with a drying tube
  2. extractioncontinuously extracted with dichloromethane for 24 hours
  3. customThe organic extracts were dried
  4. customevaporated to an oil (13.6 g)
  5. customThe oil was purified by column chromatography on silica gel

출처 및 근거

ORD 기록
ord-078b5e1a60634932a34ef14427040a33
출처 데이터셋
uspto-grants-1999_01
특허 번호
US05859255

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