Trityl chloride → S-Trityl-L-Cysteine

Participants

Reaction Conditions

Reaction Steps

L-Cysteine hydro-chloride (100 g, 0.634 mol) and trityl chloride (270 g, 0.969 mol) were stirred in DMF (400 mL) for 2 days at room temperature. A 10% sodium acetate solution (3.5 L) was then added dropwise and the white precipitate which formed was filtered and washed with distilled water. Afterward, the residue was stirred in acetone at 50° C. for 30 min after which it was cooled to 0° C. and filtered. The precipitate was washed with a little acetone and diethyl ether and dried in vacuo. S-Trityl-L-cysteine 1c (205 g, 89%) was obtained as a white powder. 1c: m.p. 192° C. (decomp); 1H NMR (300 MHz, DMSO-d6) δ 2.45 (dd, 1H, J=9 Hz, 12 Hz), 2.58 (dd, 1H, J=4.4 Hz, 12 Hz), 2.91 (m, 1H), 7.22-7.36 (m, 15H); 13C NMR (75.5 MHz, DMSO-d6): δ 33.8, 53.7, 66.4, 127.1, 127.8, 128.1, 128.4, 129.5, 144.5, 168.4. This material was directly used in the next step without further purification.

Provenance & Evidence