Reaction #1909805

Reaction equation

DNFB

2,4-Dinitrofluorobenzene

5′-O-(dimethoxytrityl)-2′-O-(hexylamino)uridine

DNFB

→

5′-O-(dimethoxytrityl)-2′-O-[hexyl-N-(2,4-dinitrophenyl)amino]uridine

Solvents

methanol

Conditions

Workup

1. 1
   workup.STIRRINGthe reaction mixture shaken an additional 30 min
2. 2
   workup.STIRRINGAfter shaking 2.5 hours
3. 3
   Concentrationthe mixture was concentrated in vacuo
4. 4
   Otherchromatographed on a silica gel column
5. 5
   Washeluting with a gradient of 25% ethyl acetate in hexanes to 100% ethyl acetate
6. 6
   WashThe desired product (0.51 grams, 46%) eluted with 100% ethyl acetate (Rf 0.85 by TLC)

Procedure

5′-O-(dimethoxytrityl)-2′-O-(hexylamino)uridine (0.88 grams, 1.37 mmol) was dissolved in methanol (20 mL). 2,4-Dinitrofluorobenzene (DNFB, 0.25 grams, 1.37 mmol) was added and the mixture shaken on a mechanical shaker. The reaction was monitored by TLC. After 90 min, another 0.25 grams of DNFB was added and the reaction mixture shaken an additional 30 min, followed by addition of another 0.25 grams of DNFB. After shaking 2.5 hours, the mixture was concentrated in vacuo and chromatographed on a silica gel column, eluting with a gradient of 25% ethyl acetate in hexanes to 100% ethyl acetate. The desired product (0.51 grams, 46%) eluted with 100% ethyl acetate (Rf 0.85 by TLC).

Source