Reaktion #733968

Reaktionsgleichung

1-bromo-4-chlorobutane

LDA

ethyl 1-cyclobutanecarboxylate

→

Compound 104b

Ethyl 1-(4-chlorobutyl)-1-cyclobutanecarboxylate

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeto give
2. 2
   Sonstigeafter purification
3. 3
   workup.DISTILLATIONby fractional distillation under reduced pressure, 104b (20.53 g, 86%) as a thin, colorless oil
4. 4
   SonstigeT=64-71° C. (p=0.001 Torr)

Vorschrift

Compound 104b was prepared, likewise the procedure described for 104c, starting from LDA (prepared from BuLi (2.5M in hexanes, 52.8 mL, 132 mmol) and iPr2NH (18.52 mL, 132 mmol, distilled from NaOH)), ethyl 1-cyclobutanecarboxylate (Török, B. et al. J. Chem. Soc. Perkin Trans. 1, 1993, 7, 801-804) (14.05 g, 110 mmol) (the resulting mixture was allowed to warm to 0° C. and cooled again to −60° C.) and 1-bromo-4-chlorobutane (19.1 mL, 165 mmol) to give, after purification by fractional distillation under reduced pressure, 104b (20.53 g, 86%) as a thin, colorless oil. bp: T=64-71° C. (p=0.001 Torr). 1H NMR: δ 4.13 (q, J=7.1 Hz, 2H), 3.51 (t, J=6.8 Hz, 2H), 2.50-2.32 (m, 2H), 1.96-1.70 (m, 8H), 1.40-1.20 (m, 2H), 1.26 (t, J=7.2 Hz, 3H). 13C NMR: δ 176.6, 60.3, 47.6, 44.8, 37.3, 32.8, 30.1 (2×), 22.4, 15.8, 14.4.

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