Triethylamine → Brassitin

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Freshly made 25 (190 mg, 1.3 mmol) and Et3N (271 μL, 1.95 mmol) was dissolved in anhydrous MeOH (10 mL). The flask was cooled to 0° C. and methyl chlorothioformate (116 μL, 1.36 mmol) was added dropwise followed by stirring at room temperature for 6 hours. A few drops of H2O were added to quench excess reagent and the volatiles were evaporated. The residue was dissolved in EtOAc (35 mL) and washed with 0.5 M HCl (2×20 mL), sat. NaHCO3 (20 mL), and brine (15 mL). The organic solution was dried with Na2SO4, filtered and concentrated to afford a crude brownish-orange solid (270 mg). After recrystallization from CH2Cl2/hexanes, beige crystals: 125 mg, 44% yd. mp 110-111° C. 1H NMR (CDCl3) δ 8.15 (br s, 1H, NH), 7.64 (d, 1H, ArH J=7.9), 7.39 (d, 1H, ArH J=7.1), 7.23 (m, 1H, ArH), 7.18 (m, 1H, ArH), 7.13 (m, 1H, ArH), 5.52 (br s, 1H, CH2NHC), 4.67 (d, 2H, ArCH2, J=5.1), 2.38 (s, 3H, SCH3). 13C NMR (CDCl3) δ 167.6, 136.3, 126.3, 123.3, 122.5, 119.9, 118.7, 112.1, 111.3, 36.9, 12.4. EI-MS m/z (%) 220 (37, M+), 205 (9), 172 (12, M+-SCH3), 130 (100). NP-HPLC r.t.=9.827 min. RP-HPLC (1/1 CH3CN/H2O+0.1% TFA) r.t.=9.512 min.

Herkunft & Nachweise