反応 #163456

反応方程式

iodine

pyridine

O-ethyl carbonisothiocyanatidate

t-butylamine

hexanal

→

title compound

収率 92.6%

ethyl [(5Z)-4-butyl-2-tert-butylisothiazol-5(2H)-ylidene]carbamate

収率 92.6%

溶媒

methanol

tetrahydrofuran

acetonitrile

反応条件

後処理

1. 1
   その他The solids were removed by vacuum filtration through a glass frit
2. 2
   濃縮the liquor was concentrated by rotary evaporator
3. 3
   その他to give the crude imine as a pale yellow oil
4. 4
   workup.ADDITIONwas added dropwise
5. 5
   workup.STIRRINGThe resulting yellow mixture was stirred at room temperature for 1 hour
6. 6
   その他to form a brown slurry
7. 7
   workup.STIRRINGThe mixture was stirred at room temperature for 2 hours
8. 8
   その他The excess iodine was quenched by addition of solid sodium metabisulfite until the mixture
9. 9
   workup.ADDITIONSaturated aqueous sodium bicarbonate solution was added
10. 10
    workup.STIRRINGthe mixture was stirred at room temperature for 15 minutes
11. 11
    抽出The mixture was extracted with dichloromethane (3×75 mL)
12. 12
    乾燥The combined organic extracts were dried (MgSO4)
13. 13
    ろ過filtered
14. 14
    濃縮concentrated by rotary evaporator
15. 15
    その他to give a brown oil
16. 16
    その他The product was purified by flash chromatography (silica gel: 25-95% ethyl acetate in hexanes)

実験手順

To a solution of hexanal (Aldrich, 20.0 g, 200 mmol) in acetonitrile (20 mL) in a 100-mL, round-bottomed flask containing molecular sieves (10 g) was added neat t-butylamine (Aldrich, 16.1 g, 220 mmol). The mixture was stirred at room temperature overnight. The solids were removed by vacuum filtration through a glass frit and the liquor was concentrated by rotary evaporator to give the crude imine as a pale yellow oil. The crude imine was dissolved in anhydrous tetrahydrofuran (200 mL) containing pyridine (Aldrich, 15.8 g, 200 mmol) and O-ethyl carbonisothiocyanatidate (Aldrich, 15.7 g, 120 mmol) was added dropwise. The resulting yellow mixture was stirred at room temperature for 1 hour. Anhydrous methanol (100 mL) and iodine (Aldrich, 30.5 g, 120 mmol) were added to form a brown slurry. The mixture was stirred at room temperature for 2 hours. The excess iodine was quenched by addition of solid sodium metabisulfite until the mixture changed to yellow. Saturated aqueous sodium bicarbonate solution was added and the mixture was stirred at room temperature for 15 minutes. The mixture was extracted with dichloromethane (3×75 mL). The combined organic extracts were dried (MgSO4), filtered, and concentrated by rotary evaporator to give a brown oil. The product was purified by flash chromatography (silica gel: 25-95% ethyl acetate in hexanes) to afford 31.6 g (56%) of the title compound. 1H NMR (DMSO-d6) δ 0.90 (t, J=7.3 Hz, 3H), 1.22 (t, J=7.1 Hz, 3H), 1.23-1.36 (m, 2H), 1.50-1.60 (m, 2H), 1.55 (s, 9H), 2.51 (t, J=7.5 Hz, 2H), 4.10 (q. J=7.1 Hz, 2H), 8.45 (s, 1H); MS (ESI+) m/z 285 (M+H)+.

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