Triethylamine → N-(3-methyl-2-nitrobenzyl)-L-alanine ethyl ester

Temperatur

60 °C

A solution of 120 ml of triethylamine in 200 ml of absolute ethanol was added dropwise over a period of 30 minutes to a solution of 91.8 g of L-alanine ethyl ester hydrochloride in 300 ml of absolute ethanol. The mixture was warmed to 60° C., a clear solution resulting. To this solution was added dropwise within 1 hour a solution of 55.5 g of 3-(chloromethyl)-2-nitrotoluene in 300 ml of absolute ethanol. Thereafter, the temperature was increased to 80° C. and the mixture was stirred at this temperature overnight. Thereafter, the mixture was evaporated to dryness under reduced pressure and the residue was dissolved in 600 ml of water. The solution was extracted three times with methylene chloride and the extracts were washed successively with water and with saturated sodium chloride solution, dried and evaporated. The thus-obtained crude product was purified by chromatography on silica gel using methylene chloride/5% methanol for the elution. There was obtained N-(3-methyl-2-nitrobenzyl)-L-alanine ethyl ester in the form of a yellow oil; [α]D =-36° (c=1% in methanol).

1. customa clear solution resulting
2. temperatureThereafter, the temperature was increased to 80° C.
3. customThereafter, the mixture was evaporated to dryness under reduced pressure
4. dissolutionthe residue was dissolved in 600 ml of water
5. extractionThe solution was extracted three times with methylene chloride
6. washthe extracts were washed successively with water and with saturated sodium chloride solution
7. customdried
8. customevaporated
9. customThe thus-obtained crude product
10. customwas purified by chromatography on silica gel
11. washfor the elution

ORD-Eintrag

ord-5e1a7c3b4bd34045881c833d66613aa9

Quelldatensatz

uspto-grants-1981_03

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04256748