2,4-Dichlorophenol → HCID 56649063, Verbindung

Temperatur

-78 °C

Phenyl phosphorodichloridate (10.0 g, 47.4 mmol) was dissolved in 60 mL of dry DCM and subsequently cooled to −78° C. Slow addition of a preformed mixture of 2,4-dichlorophenol (7.73 g, 47.4 mmol) and triethylamine (7.27 mL, 52.1 mmol) in 20 mL of DCM was followed by stirring at above temperature for 30 min. The reaction was brought to 0° C. and stirred for 2.5 h at this temperature before (L)-alanine isopropyl ester (7.95 g, 47.4 mmol) was added as a solid in one batch. Stirring for 40 min at 0° C. was then followed by addition of more triethylamine (13.9 mL, 99.54 mmol) and additional stirring for 3 h at 0° C. or until judged complete by TLC (ethyl acetate/hexane=1/3). The reaction mixture was subsequently evaporated under reduced pressure and finally submitted to column chromatography (ethyl acetate in hexane) on silica gel to yield the product (mixture of two isomers) in 66% yield (13.6 g) as a viscous colorless oil.

1. customwas brought to 0° C.
2. additionwas added as a solid in one batch
3. stirringStirring for 40 min at 0° C.
4. stirringadditional stirring for 3 h at 0° C.
5. customThe reaction mixture was subsequently evaporated under reduced pressure
6. customto yield
7. additionthe product (mixture of two isomers) in 66% yield (13.6 g) as a viscous colorless oil

ORD-Eintrag

ord-9d11396abde641069246eb982963eabb

Quelldatensatz

uspto-grants-2013_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08563530B2