Reaktion #624629

Reaktionsgleichung

3-methylbutanal

ethyl 4-iodobenzoate

isopropylmagnesium chloride lithium chloride

→

ethyl 4-(1-hydroxy-3-methylbutyl)benzoate

Ausbeute 94.0%

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturmaintaining the internal temperature below −30° C
2. 2
   Temperaturmaintaining the internal temperature below −35° C
3. 3
   workup.ADDITIONthe addition
4. 4
   workup.STIRRINGto stir for 15 minutes at −35° C.
5. 5
   SonstigeThe reaction was quenched with 1 N aqueous hydrochloric acid (400 mL)
6. 6
   Extraktionthe mixture was extracted with ethyl acetate (2×200 mL)
7. 7
   WaschenThe organics were washed with brine (200 mL) and water (200 mL)
8. 8
   Trocknendried over sodium sulfate
9. 9
   Filtrationfiltered
10. 10
    Einengenconcentrated

Vorschrift

To a solution of ethyl 4-iodobenzoate (20 g, 72 mmol) in tetrahydrofuran (200 mL) at −40° C. was added isopropylmagnesium chloride lithium chloride (62 mL, 80 mmol, 1.3 M in THF) dropwise, maintaining the internal temperature below −30° C. The mixture was stirred for 30 minutes and 3-methylbutanal (8.68 g, 101 mmol) was then added dropwise, maintaining the internal temperature below −35° C. Following the addition, the reaction was allowed to stir for 15 minutes at −35° C. and was then allowed to warm to room temperature. The reaction was quenched with 1 N aqueous hydrochloric acid (400 mL), and the mixture was extracted with ethyl acetate (2×200 mL). The organics were washed with brine (200 mL) and water (200 mL), dried over sodium sulfate, filtered and concentrated to give ethyl 4-(1-hydroxy-3-methylbutyl)benzoate (16 g, 93%) as an oil. 1H NMR (400 MHz, CDCl3, δ): 7.95 (d, J=8.4 Hz, 2H), 7.34 (d, J=8.4 Hz, 2H), 4.73-4.76 (m, 1H), 4.28-4.33 (m, 2H), 1.60-1.71 (m, 2H), 1.41-1.46 (m, 1H), 1.31-1.39 (m, 3H), 0.87-0.92 (m, 6H).

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