反应详情

The procedure of Example 13 is followed, but the endcapper is 4'-chloro-3-dimethylaminopropiophenone (0.10 g, 0.47 mmol) to yield the ketone-functionalized macromonomer. The product has structure 1, where G1 is benzoyl, G2 through G4 are hydrogen, E is 4'-(3-dimethyl-aminopropionyl)phenyl, and DPn ≈28. This oligomer can be converted to the more useful acrylyl-terminated form by thermally induced loss of dimethylamine. 4'-Chloro-3-dimethylaminopropiophenone is prepared by treating 4'-chloro-3-dimethylaminopropiophenone hydrochloride with aqueous base to remove the HCl. The free amine is extracted into diethyl ether and recovered by evaporation of the solvent. The hydrochloride salt is prepared by the method of Maxwell in Org. Synth. Coll. Vol. III, 305-306. Thus, a mixture of 4-chloroacetophenone, dimethylamine hydrochloride, and paraformaldehyde is refluxed for 2-4 hours in 95% ethanol with a small amount of added hydrochloric acid. The solid product is obtained after adding acetone and cooling overnight.

1. customterminated form by thermally induced loss of dimethylamine
2. customto remove the HCl
3. extractionThe free amine is extracted into diethyl ether
4. customrecovered by evaporation of the solvent
5. customThe solid product is obtained
6. temperaturecooling overnight