Diazolidinyl urea

Chemistry

Synthesis

Diazolidinyl urea is produced by the chemical reaction of allantoin and formaldehyde in the presence of sodium hydroxide solution and heat. The reaction mixture is then neutralized with hydrochloric acid and evaporated:

:[[File:Allantoin.svg|150px|Allantoin]] + 4 H2C=O → [[Image:Diazolidinyl urea correct formula.png|200px|Diazolidinyl urea]]

Structure

Diazolidinyl urea was poorly characterized until recently and the single Chemical Abstracts Service structure assigned to it is probably not the major one in the commercial material. Instead, new data indicate that one of the hydroxymethyl functional groups of the imidazolidine ring is attached to the carbon, rather than on the urea nitrogen atom: :{| |- align="center" valign="middle" | [[Image:Diazolidinyl urea erroneous formula.png|200px|Originally reported structure]] | [[Image:Diazolidinyl urea correct formula.png|200px|Hoeck's revised structure]] |- align="center" | Originally reported structure | Hoeck's revised structure |}

Safety

Some people have a contact allergy to imidazolidinyl urea causing dermatitis. Such people are often also allergic to diazolidinyl urea.

In addition to being an allergen, it is a formaldehyde releaser, since it generates formaldehyde slowly as it degrades. Although the formaldehyde acts as a bactericidal preservative, it is a known carcinogen.

In 2005–06, it was the 14th-most-prevalent allergen in patch tests (3.7%).

References

References

1. {{GHS class NZ
2. (2006). "Characterization and chemistry of imidazolidinyl urea and diazolidinyl urea". Contact Dermatitis.
3. [https://web.archive.org/web/20131107214747/http://ntp.niehs.nih.gov/ntp/htdocs/Chem_Background/ExSumPDF/ImidazolidinylUrea_508.pdf Review of toxicological data] (NTP NIEHS)
4. (May–June 2009). "Patch-test results of the North American Contact Dermatitis Group 2005–2006". Dermatitis.