PEG4-acid synthesis

Yield:-

Reaction Conditions:

with trifluoroacetic acid in 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran

Steps:

16 3-{2-[2-(2-Hydroxyethoxy)ethoxy]ethoxy}propanoic acid
3-{2-[2-(2-Hydroxyethoxy)ethoxy]ethoxy}propanoic acid To a solution of 300 mg (1.08 mmol) of tert-butyl 12-hydroxy-4,7,10-trioxadodecanoate in 6 ml of DCM are added 1.6 ml (21.56 mmol) of TFA. Stirring is continued at RT for 3 hours. The mixture is concentrated to dryness, taken up in a minimum amount of DCM and entrained several times with toluene to give compound 50 in the form of a pale yellow oil (240 mg, quantitative).

References:

SANOFI US2012/225089, 2012, A1