a base and then providing the product to the process the preferred formaldehyde source is paraformaldehyde or about a 37 formaldehyde solution the preferred acid used in this process is concentrated hydrochloric acid however other strong protic acids are suitable other suitable acids include hydrobromic hydroiodic sulfuric and phosphoric acids these acids may be regarded as strong protic acids the concentration of the protic acid should be about 3 6 mole equivalents of acid per mole equivalent of formaldehyde source the reaction may proceed by first adding hydantoin followed by the formaldehyde source and while stirring adding concentrated hydrochloric acid however the exact sequence of reactant addition is not important the total water content of the initial reaction mixture is about 35 90 weight the preferred amount is about 35 75 weight and the most preferred amount is about 35 50 weight at the end of the reaction period water is added the reaction mixture is filtered and the mbh product is dried to a nitrogen purged three neck round bottom flask equipped with overhead stirrer water condenser and nitrogen line were added 10 11 grams 100 mmol of 99 hydantoin and 1 58 grams 50 mmol of 95 paraformaldehyde while the mixture was stirred 14 ml of concentrated hcl was added the mixture was stirred at room temperature overnight the initial water content in this reaction mixture was 37 by weight after about 20 hours 15 ml of water was added to the.