N-Fluorobenzenesulfonimide → 2-(4-Ethyl-2-fluorophenyl)-4,4-dimethyl-4,5-dihydrooxazole

HRID 39628

反応式

HRID 39628 の反応式
[CH2:1]([C:3]1[CH:8]=[CH:7][C:6]([C:9]2[O:10][CH2:11][C:12]([CH3:15])([CH3:14])[N:13]=2)=[CH:5][CH:4]=1)[CH3:2].C([Li])CCC.C1C=CC(S(N(S(C2C=CC=CC=2)(=O)=O)[F:31])(=O)=O)=CC=1>C1COCC1.CCCCCC>[F:31][C:7]1[CH:8]=[C:3]([CH2:1][CH3:2])[CH:4]=[CH:5][C:6]=1[C:9]1[O:10][CH2:11][C:12]([CH3:14])([CH3:15])[N:13]=1

参加物

6

反応物 3

HCID 588007N-FluorobenzenesulfonimideHCID 128725592-(4-Ethylphenyl)-4,4-dimethyl-2-oxazolineHCID 178418339Butyllithium

生成物 1

HCID 450954212-(4-Ethyl-2-fluorophenyl)-4,4-dimethyl-4,5-dihydrooxazole収率 94,529.797%

試薬・触媒・溶媒 2

HCID 8058Hexane触媒HCID 8028Tetrahydrofuran溶媒

反応条件

温度
-70 °C

実験手順

The 4-ethylphenyloxazoline (2.03 g, 10 mmol) was dried in a vacuum oven at 60° C. for 2-3 hours, dissolved in 50 mL of dry THF, and charged to a 300 mL round bottom flask equipped with a thermometer, nitrogen inlet, and magnetic stir bar. The mixture was cooled under nitrogen to −70° C. in a dry ice/acetone bath. Butyl lithium in hexane (7.5 mL, 0.012 mmol) was added in two portions and warmed to −25° C. over 2 hours. The mixture was cooled again to −65° C. and N-fluorobenzenesulfonimide (3.79 g, 0.012 mmol) was added in three portions. The mixture was allowed to warm to room temperature and was stirred overnight. The reaction mixture was quenched with 100 mL of saturated NH4Cl, and transferred to a separatory funnel with ethyl ether washes. 25% NaOH was added slowly and mixed until an aqueous phase with pH=10 was achieved. The aqueous phase was extracted with ether and the ether was washed with a small volume of water. The ether extracts were dried over MgSO4 and evaporated to give 2.51 g of 2-(2-fluoro-4-ethyl-phenyl)-4,4-dimethyl-4,5-dihydro-oxazole as a brown oil. In a second experiment, a rate of 70% fluorination was achieved (highest) with a reactant ratio of 1:1.5:1.5 oxazoline:BuLi:N-fluorobenzenesulfonimide. 1H NMR (300 MHz, CDCl3) δ (ppm): 7.0 (d, 2H), 7.78 (t, 1H), 4.1 (s, 2H), 2.7 (q, 2H), 1.39 (s, 6H), 1.2 (t, 3H).

後処理

  1. additioncharged to a 300 mL round bottom flask
  2. customequipped with a thermometer, nitrogen inlet, and magnetic stir bar
  3. temperaturewarmed to −25° C. over 2 hours
  4. temperatureThe mixture was cooled again to −65° C.
  5. temperatureto warm to room temperature
  6. customThe reaction mixture was quenched with 100 mL of saturated NH4Cl
  7. customtransferred to a separatory funnel with ethyl ether washes
  8. addition25% NaOH was added slowly
  9. additionmixed until an aqueous phase with pH=10
  10. extractionThe aqueous phase was extracted with ether
  11. washthe ether was washed with a small volume of water
  12. dry with materialThe ether extracts were dried over MgSO4
  13. customevaporated

出典と根拠

ORDレコード
ord-b0f49f75e16b481c9b9da24c027c6677
出典データセット
uspto-grants-2013_09
特許番号
US08524948B2

関連ノート

読み込み中…