hours and then is cooled to 25 u00b0 30 u00b0 c at 25 u00b0 30 u00b0 c the product is a slightly viscous yellow solution which does not crystallize the p 31 nmr spectra of a sample indicates the reaction product contains pvpac into a 250 ml flask equipped with a water condenser and a dropping funnel are charged 33 grams 0 20 mole of 49 9 orthophosphorous acid containing 3 1 grams of hcl and 4 2 grams of 37 hydrochloric acid for a total of 7 3 grams 0 20 mole of hcl to the acid mixture is added 31 8 grams 0 20 mole of polyvinyl benzpyrrolidone and 25 milliliters of water the mixture is heated with stirring until solution is obtained and heating is continued until reflux is obtained at approximately 108 u00b0 c the solution is maintained at reflux for one hour and then over a period of 2 hours there is slowly added 7 35 grams 0 22 mole of 90 paraformaldehyde after addition of formaldehyde the reaction mixture which is a clear pale yellow solution is held at reflux for an additional period of 6 hours a sample taken for nmr analysis shows a typical ppm chemical shift at 9 3 and indicates that 10 of the cyclic amide has been converted to pvpac of the present.