Reacción #3194
ord-158b075907054ab39ba581443375f769
Ecuación de reacción
Reactivos
Disolventes
Condiciones de reacción
Tratamiento posterior
- 1ConcentraciónThe resulting mixture was concentrated under reduced pressure
- 2Otrothe dark residue was partitioned between 100 mL of THF and 100 mL of brine/50 mL water solution in a 500 mL separatory funnel
- 3Otroto separate
- 4Extracciónthe aqueous phase was extracted with THF (2×100 mL)
- 5LavadoThe combined THF extracts were washed with brine (2×50 mL)
- 6Secadodried over MgSO4
- 7Concentraciónconcentrated to an oily residue
- 8workup.ADDITIONHere, CH2Cl2 was added very carefully
- 9Otroprecipitation of the crude product
- 10Filtraciónthe suspension was filtered with a medium glass fritted funnel
- 11Otroair dried for several minutes
- 12Temperatura80 mL of diethyl ether at reflux
- 13Filtraciónhot filtered
- 14Otroto remove some impurities
- 15workup.DISSOLUTIONThe crude product was dissolved in a mixture of acetone and methanol (sonication may be required)
- 16workup.ADDITION6 grams of deactivated silica gel was added to the orange solution
- 17ConcentraciónThe slurry was concentrated to dryness
- 18Otrothe orange solid was dried in vacuo for one hour
- 19LavadoThe column was eluted
- 20Temperaturawith increasing concentration of methanol (0-10%)
- 21OtroAfter a bright yellow impurity (monoalkylated product) was removed a colorless product
- 22Lavadoto elute (using 8-10% methanol in CHCl3 eluents)
- 23LavadoConversely, on TLC the product will elute faster than the bright yellow monoalkylated product
- 24OtroThe purified dialkylated tetrahydroxy product can be recrystallized from acetone/diethyl ether
Procedimiento
8C, FIG. 8. 1,2-Dihydroxy-4,5-dinitrobenzene 8B (5.0 g, 22 mmol) and 1-chloro-2,3-dihydroxypropane (12.1 g, 110 mmol) were refluxed for 48 hours in a solution of potassium hydroxide (4.4 g) in 1-butanol (100 mL) under a nitrogen atmosphere. The resulting mixture was concentrated under reduced pressure, and the dark residue was partitioned between 100 mL of THF and 100 mL of brine/50 mL water solution in a 500 mL separatory funnel. The mixture was allowed to separate and the aqueous phase was extracted with THF (2×100 mL). The combined THF extracts were washed with brine (2×50 mL), dried over MgSO4 and concentrated to an oily residue. Here, CH2Cl2 was added very carefully to insure precipitation of the crude product. After stirring for 15 minutes, the suspension was filtered with a medium glass fritted funnel and air dried for several minutes. The orange solid was taken up in 120 mL of CHCl3 and 80 mL of diethyl ether at reflux and hot filtered to remove some impurities. The crude product was dissolved in a mixture of acetone and methanol (sonication may be required), then 6 grams of deactivated silica gel was added to the orange solution. The slurry was concentrated to dryness and the orange solid was dried in vacuo for one hour. The orange solid was loaded on a packed deactivated silica gel column. The column was eluted starting with neat CHCl3 followed by CHCl3 with increasing concentration of methanol (0-10%). After a bright yellow impurity (monoalkylated product) was removed a colorless product began to elute (using 8-10% methanol in CHCl3 eluents). Conversely, on TLC the product will elute faster than the bright yellow monoalkylated product. The purified dialkylated tetrahydroxy product can be recrystallized from acetone/diethyl ether to yield 2.60 grams (30%) of a light yellow fluffy solid. 1H NMR (d6 -acetone): δ2.95 (bs, 4H, OH), 3.69 (d, 4H, OCH2CH(OH)CH2OH), 4.06 (p, 2H, OCH2CH(OH)CH2 OH), 4.24-4.35 (m, 4H, OCH2CH(OH)CH2OH), 7.72 (s, 2H, Ar--H); 13C NMR (d6 -acetone): δ63.55, 70.89, 72.53, 109.99, 137.22, 152.77. CI MS 349.