Diisopropylamine → HCID 90014806, Verbindung

Temperatur

-40 °C

29.1 ml (72.8 mmol) of a 2.5 M solution of n-butyllithium in hexane were added dropwise to a solution, cooled to −40° C., of 10.2 ml (72.8 mmol) of diisopropylamine in 35 ml of abs. THF. After the end of the addition, the mixture was stirred at −40° C. for another 30 min and then cooled to −78° C., and a solution of 7.1 ml (72.8 mmol) of ethyl acetate in 10 ml of abs. THF was added dropwise. The reaction mixture was stirred at −78° C. for 30 min, and a solution of 8.50 g (60.54 mmol) of ethyl 3-cyclopropylacrylate in a little THF was then added dropwise. After 1 h at −78° C., the mixture was slowly warmed to −40° C., then to 0° C., and a saturated aqueous ammonium chloride solution was finally added. After extraction with ethyl acetate, the organic phase was washed with 1 N hydrochloric acid and sat. sodium chloride solution, dried over sodium sulphate and concentrated under reduced pressure. The crude product was purified by chromatography on silica gel (mobile phase cyclohexane/ethyl acetate 30:1→6:1). This gave 3.28 g of the target product (23.7% of theory).

1. additionAfter the end of the addition
2. temperaturecooled to −78° C.
3. stirringThe reaction mixture was stirred at −78° C. for 30 min
4. waitAfter 1 h at −78° C.
5. temperaturethe mixture was slowly warmed to −40° C.
6. extractionAfter extraction with ethyl acetate
7. washthe organic phase was washed with 1 N hydrochloric acid and sat. sodium chloride solution
8. dry with materialdried over sodium sulphate
9. concentrationconcentrated under reduced pressure
10. customThe crude product was purified by chromatography on silica gel (mobile phase cyclohexane/ethyl acetate 30:1→6:1)

ORD-Eintrag

ord-d569f963c4b54ceab09e4e88f1d2cfcb

Quelldatensatz

uspto-grants-2016_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09309198B2