Ethanolamine → 2-Phenyl-2-oxazoline

Linear polyethyleneimine with a number average molecular weight of about 30,000 as determined by gel permeation chromatography was prepared as follows. Ethanolamine (304 grams) was added over a period of 90 minutes to a stirred suspension of 16.5 grams of cadmium acetate dihydrate in 512 grams of benzonitrile at 130° C. After 16 hours, distillation of the mixture yielded a clear fraction of 2-phenyl-2-oxazoline boiling at 82° C. and at a pressure of 1.5 millimeters of mercury. Subsequently, 2-phenyl-2-oxazolium perchlorate was prepared by adding 19.5 grams of perchloric acid to 20 grams of 2-phenyl-2-oxazoline in 20 milliliters of water and 20 milliliters of ethanol. The resultant solution was cooled to -20° C. to form white crystals of 2-phenyl-2-oxazolium perchlorate, which were isolated by filtration and dried in vacuo at 30° C. Polymerization of 2-phenyl-2-oxazoline was then effected by heating a mixture of 0.52 gram of 2-phenyl-2-oxazolium perchlorate and 100 grams of 2-phenyl-2-oxazoline to 150° C. in an oil bath with stirring under argon. The mixture became too thick to stir within 1 hour. The resulting light yellow solid is poly(2-phenyl-2-oxazoline).

1. customwas prepared
2. distillationdistillation of the mixture

ORD record

ord-c954194991ff4f2ba6e8f1261a7cab0e

Source dataset

uspto-grants-1991_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05017644