Reaktion #1004084

Reaktionsgleichung

N-Boc-L-tyrosine methyl ester

triethylamine

methanesulfonyl chloride

→

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

Ausbeute 96.4%

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   WaschenThe reaction mass was washed with 5% hydrochloric acid (72.9 g) and 5% aqueous sodium bicarbonate (84.0 g)
2. 2
   Trocknendried over magnesium sulfate
3. 3
   Einengenconcentrated under reduced pressure with a rotary evaporator
4. 4
   SonstigeAfter crystallization from the concentrate mass with n-hexane
5. 5
   Sonstigeprecipitated crystals
6. 6
   Filtrationwere collected by filtration
7. 7
   Sonstigedried

Vorschrift

N-Boc-L-tyrosine methyl ester 3 (29.5 g, 0.1 mol) and triethylamine (20.2 g, 0.2 mol) were dissolved in toluene (147.7 g) and then cooled to 0° C. To the mixture was added dropwise methanesulfonyl chloride (13.8 g, 0.12 mol) at 0° C. over 40 min. The mixture was further kept at 0° C. for 25 min. The reaction mass was washed with 5% hydrochloric acid (72.9 g) and 5% aqueous sodium bicarbonate (84.0 g), dried over magnesium sulfate, and then concentrated under reduced pressure with a rotary evaporator. After crystallization from the concentrate mass with n-hexane, precipitated crystals were collected by filtration and dried to give N-Boc-O-methanesulfonyl-L-tyrosine methyl ester 6 (36.0 g, yield 96%) as white crystals.

Quelle