Reaktion #1004082

Reaktionsgleichung

N-Boc-L-tyrosine methyl ester

tosyl chloride

triethylamine

→

N-Boc-O-tosyl L-tyrosine methyl ester

Ausbeute 93.4%

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   WaschenThe reaction mass was washed with 5% hydrochloric acid (255 g) and 5% aqueous sodium bicarbonate (294 g)
2. 2
   Einengenconcentrated at 35° C. under reduced pressure until the weight of the toluene layer
3. 3
   TemperaturAfter cooling to −10° C., to the concentrate
4. 4
   workup.ADDITIONwas added dropwise n-hexane (310 g) over 3 hrs
5. 5
   FiltrationDeposited crystals was filtered
6. 6
   Sonstigedried

Vorschrift

N-Boc-L-tyrosine methyl ester 3 (103 g, 0.35 mol) and tosyl chloride (66.7 g, 0.35 mol) were dissolved in toluene (517 g) and then cooled to 0° C. To the mixture was added dropwise triethylamine (35.5 g, 0.35 mol) at 0° C. over 90 min. The mixture was further kept at 0° C. for 4 hrs. The reaction mass was washed with 5% hydrochloric acid (255 g) and 5% aqueous sodium bicarbonate (294 g) and then concentrated at 35° C. under reduced pressure until the weight of the toluene layer reached to 243 g. After cooling to −10° C., to the concentrate was added dropwise n-hexane (310 g) over 3 hrs. Deposited crystals was filtered and dried to give N-Boc-O-tosyl L-tyrosine methyl ester 4 (147 g, yield 92%) as white crystals.

Quelle