Sodium Carbonate → Biotin

Reaktionsgleichung

S=[C:2]([CH2:6][CH2:7][CH2:8][C@H:9]1[C@@H:17]2[C@@H:12]([NH:13][C:14]([NH:16]2)=[O:15])[CH2:11][S:10]1)[C:3](=[O:5])[OH:4].BrC(O)C.C(=O)([O-])[O-].[Na+].[Na+]>COCCOCCOC>[OH:5][C:3]([CH2:2][CH2:6][CH2:7][CH2:8][C@H:9]1[C@@H:17]2[C@@H:12]([NH:13][C:14]([NH:16]2)=[O:15])[CH2:11][S:10]1)=[O:4]

Komponenten

Versuchsvorschrift

A diglyme solution (3 ml) containing dl-thioxobiotin (255 mg, 0.981 mol) and bromoethanol (140 μl, 1.98 mmol) was allowed to reflux (150°) for 2.5 hours. The solution was cooled, dilute sodium carbonate (50 ml) was added, and the solution was extracted with hexane (50 ml). The pH of the aqueous phase was adjusted to 1.5 with 6N HCL and extracted with ethyl acetate (4×100 ml). The ethyl acetate extract was dried over magnesium sulfate, filtered and concentrated in vacuo to give 148 mg (62%) of crude biotin, mp 220°-223° C. which was recrystallized from water IR (KBr) 3279, 2899, 1724; NMR (d, DMSO) 0.76-1.95 (6H, m, C--CH2), 2.00-2.40 (2H, t, CH2 --CO), 2.70-2.98 (1H, m, CH2S) 3.00-3.54 (2H, m, CH2S, CHS) 4.00-4.44 (2H, m, CHN), 6.44 (1H, bs, NH), 6.55 (1H, bs, NH), 11.8-12.4 (1H, bs, OH). Analysis calculated for C10H16O3N2S: C, 49.18; H, 6.56; N, 11.48; Found: C, 49.30; H, 6.34; N, 11.37. Mass spectrum: calculated: 244.0880, found: 244.0925.