Trityl chloride → S-Trityl-L-Cysteine

HRID 1921965Notes

Reaction equation

Cl.[NH2:2][C@H:3]([C:6]([OH:8])=[O:7])[CH2:4][SH:5].[C:9](Cl)([C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1)([C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1)[C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1.C([O-])(=O)C.[Na+]>CN(C=O)C>[C:9]([S:5][CH2:4][C@@H:3]([C:6]([OH:8])=[O:7])[NH2:2])([C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1)([C:22]1[CH:23]=[CH:24][CH:25]=[CH:26][CH:27]=1)[C:16]1[CH:17]=[CH:18][CH:19]=[CH:20][CH:21]=1

Participants

Conditions

Temperature: 50 °C

Procedure

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.

Workup

customthe white precipitate which formed
filtrationwas filtered
washwashed with distilled water
temperaturewas cooled to 0° C.
filtrationfiltered
washThe precipitate was washed with a little acetone and diethyl ether
customdried in vacuo

Sources & evidence

ORD record: ord-b4e07d4488eb4324a013feb577d91eba
Source dataset: uspto-grants-2012_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08173809B2

Reaction notes

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