Pyridine → 2,2-Dimethyl-4-vinyl-1,3-dioxolane

Beteiligte Stoffe

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Reaktionsschritte

The maleamic acid copolymer of Example 8 was cyclized as follows. The procedure described in Example 8 was repeated, but prior to precipitation pyridine (2 grams, 25 mmol) was added, the solution stirred for 15 minutes, followed by the addition of 3 grams (29 mmol) of acetic anhydride. The solution was heated to 50° C. and stirred for 1 hour. The reaction mixture was then diluted with 5 grams acetone and precipitated into a heptane/ethyl ether (2:1) mixture. The solid product was collected using suction filtration and dried under vacuum at 40° C. for 20 hours. Yield was 0.54 grams of a maleamic acid/dioxolane copolymer 27% theory. Mn=2900, Mw=5420, Mw/Mn=1.87. The NMR spectrum indicates that the phenyl group has been incorporated in an approximately 1 to 1 ratio with the dioxolane group. The NMR spectrum is similar to the spectrum of a copolymer obtained by polymerizing a preformed n-phenyl maleimide monomer with a 2,2-dimethyl-4-vinyl-1,3-dioxolane monomer.

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