Reacción #1256731
ord-a1c8457bc9304946aeaf37941d81cffe
Ecuación de reacción
Disolventes
Condiciones de reacción
Tratamiento posterior
- 1Otroequipped with a magnetic stirring bar
- 2Temperaturato cool at ambient temp for 10 min
- 3ExtracciónThe mixture was extracted with isopropyl acetate (200 mL×4)
- 4Concentraciónconcentrated in vacuo
- 5workup.ADDITIONThe residue was mixed with silica gel (3 g)
- 6Otrocrushed into a fine powder
- 7Otrodry
- 8OtroThe residue was purified via gradient elution
Procedimiento
Referring to Scheme 4, a 50-mL round bottom flask equipped with a magnetic stirring bar was charged with HPTS (9.5 mmols, 5 g) and 30% H2SO4 (35 mL). The mixture was heated at 150° C. for 20 min and then allowed to cool at ambient temp for 10 min. The solution was poured into 100 g of crushed ice and diluted to 200 mL with water. The mixture was extracted with isopropyl acetate (200 mL×4) and concentrated in vacuo. The residue was mixed with silica gel (3 g) and crushed into a fine powder and dry loaded onto a Biotage 40 M cartridge. The residue was purified via gradient elution using 5% MeOH: (5% NEt3:CH2Cl2) to 15% MeOH: (5% NEt3:CH2Cl2) to give the triethylamine salt of 1 (0.281 g). The salt was treated with 1 M HCl and extracted with isopropyl acetate and the isopropyl acetate layer dried over MgSO4 and concentrated in vacuo to give 1 as a brown/green foam. Synthesis of 1 was reported previously by E. Tietze and O. Bayer 1939 Ann 540:189-210. TLC (MeOH: CH2Cl2:NEt3, 2:7:1) Rf=0.23. 1H NMR (500 MHz, CD3OD) δ7.94 (t, J=7.6 Hz, 1H), 7.97 (d, J=9.4 Hz, 1H), 8.02 (d, J=9.2 Hz, 1H), 8.11 (t, J=7.7 Hz, 2H), 8.25 (s, 1H), 8.39 (d, J=9.1 Hz, 1H), 8.98 (d, J=9.3 Hz, 1H).