Reaction #5649

Reaction equation

Et3N

amine-hydrochloride

1,3,5-trisbromomethyl benzene

sulfonyl chloride

N-tritylethanolamine

amine

1,3,5-trisbromomethyl benzene

sulfonyl chloride

4-(5-Chlorosulfonyl-2,4-dimethoxyphenyl)-2,6-pyridine dicarboxylic acid dimethyl ester

→

SiO2

4-(2,4-Dimethoxyphenyl)pyridine-2,6-dicarboxylic Acid

Solvents

water

CH2Cl2

MeOH CHCl3

CH2Cl2

Conditions

Workup

1. 1
   TemperatureThe mixture was then cooled to 5°-10° C.
2. 2
   workup.ADDITIONwas added
3. 3
   workup.STIRRINGstirring continued overnight
4. 4
   Extractionextracted with CH2Cl2
5. 5
   WashThe extract was washed with water
6. 6
   Dryingdried (Na2SO4)
7. 7
   Otherthe solvent removed
8. 8
   Otheryielding crude 43

Procedure

To a suspension of 0.5 g (0.0008 mole) of the amine-hydrochloride 8 in 20 ml of CH2Cl2 was added all at once 1.4 ml (0.01 mole) of Et3N. The mixture was then cooled to 5°-10° C. and 1.4 g (0.0032 mole) of the sulfonyl chloride 39 in 20 ml of CH2Cl2 was slowly added in a dropwise fashion. The reaction was then allowed to stir at room temperature for 30 minutes after which a TLC was taken. Little of the sulfonyl chloride 9 had reacted by TLC so an additional 100 mg of the amine 8 was added and stirring continued overnight. The mixture was then poured into water and extracted with CH2Cl2. The extract was washed with water, dried (Na2SO4) and the solvent removed yielding crude 43. After column chromatography with SiO2 /5%MeOH/CHCl3, 1.55 g (93%) of the desired tetraamide 43 was obtained.

Source