PMC:7571312 / 37147-38414 JSONTXT 6 Projects

Annnotations TAB TSV DIC JSON TextAE

Id Subject Object Predicate Lexical cue
T256 0-288 Sentence denotes A 3 L multineck flask equipped with an overhead stirrer and internal thermometer was charged with methyl N-(tert-butoxycarbonyl)-3-[(3S)-2-oxopyrrolidin-3-yl]-l-alaninate (compound 5)33 (205 g, 716 mmol) followed by methanol (1 L), and the solution was cooled to 0 °C using ice/NaCl bath.
T257 289-491 Sentence denotes NaOH (115 g in 950 mL water, 2.9 mol) solution was precooled to 0 °C and then added to the flask via a pressure-equalizing dropping funnel at such a rate to maintain the internal temperature below 5 °C.
T258 492-679 Sentence denotes The resulting solution was stirred at 0 °C for 1 h before neutralizing with conc. hydrochloric acid (keeping the internal temperature below 10 °C) and then removing the methanol in vacuo.
T259 680-865 Sentence denotes The residue was diluted with ethyl acetate (400 mL), acidified to pH 3 with conc. hydrochloric acid, and then the mixture was transferred to a sep funnel, and the organics were removed.
T260 866-1069 Sentence denotes The aqueous was extracted with ethyl acetate (2 × 400 mL), and the combined organics were washed with brine, dried over MgSO4, filtered, and concentrated to yield the title compound as a white foam, 95%.
T261 1070-1267 Sentence denotes 1H NMR (400 MHz, MeOD) δ 3.98–4.28 (m, 1H), 3.25–3.41 (m, 2H), 2.44–2.57 (m, 1H), 2.29–2.41 (m, 1H), 2.03–2.14 (m, 1H), 1.73–1.90 (m, 2H), 1.44 (s, 9H); MS (APCI−) for C12H20N2O5m/z 272.3 (M – H)−.