反应详情

Compound 138 (1.0 g, 2.6 mmol) was heated at reflux with aqueous HCl (6 M, 10 mL) for 50 min. The homogeneous solution was evaporated to dryness and the residue was taken up in distilled water (10 mL). The pH was adjusted to 9 with 25% aqueous ammonia, the resulting solution was filtered to remove insoluble matter, and the solution acidified to pH 4 with glacial acetic acid. Cooling the solution overnight gave a solid, which was collected by filtration, washed with cold water, and air-dried. Recrystallization from 20% ethanol/H2O gave the pure product (500 mg, 1.5 mmol, 57%), mp 241-242° C. (lit17 mp 247-248° C.); 1H NMR (300 MHz, DMSO-d6) δ 6.58 (d, 2H, J=7.8 Hz), 7.43 (d, 2H, J=8.1 Hz), 8.43 (s, 2H); 13C NMR (75 MHz, DMSO-d6) δ 112.8, 125.9, 128.0, 153.1, 157.6, 166.0; LRMS (LCQ, ESI+) calcd for C8H10N5O4S3 336.0, found 335.8 (M+H)+; HRMS (ESI+, m/z) calcd for C8H10N5O4S3 335.9889, found 335.9883 (M+H)+.

1. customThe homogeneous solution was evaporated to dryness
2. filtrationthe resulting solution was filtered
3. customto remove insoluble matter
4. temperatureCooling the solution overnight
5. customgave a solid, which
6. filtrationwas collected by filtration
7. washwashed with cold water
8. customair-dried
9. customRecrystallization from 20% ethanol/H2O