Thioamide
class of chemical compounds
A thioamide (rarely, thionamide, but also known as thiourylenes) is a functional group with the general structure R1−C(=S)−NR2R3, where R1, R2 and R3 are any groups (typically organyl groups or hydrogen). Analogous to amides, thioamides exhibit greater multiple bond character along the C-N bond, resulting in a larger rotational barrier.
Synthesis
Thioamides are typically prepared by treating amides with phosphorus pentasulfide, a reaction first described in the 1870s. An alternative to P2S5 is its more soluble analogue Lawesson's reagent. These transformations can be seen in the synthesis of tolrestat.
Specialized methods
The Willgerodt-Kindler reaction provides a route to thioamides from aryl-alkyl ketones.
Nitriles react with hydrogen sulfide to afford thioamides. The reaction can be catalyzed by both base and acid:
Imidoyl chlorides react with hydrogen sulfide to produce thioamides.
Thioacylation is possible, but not with thioic acids, as amines preferentially displace the sulfur. Thionoesters form amidines with primary amines, but thioacylate secondary amines perfectly well.
Begin with the source’s own compact description: “Thioamide” is class of chemical compounds. The dossier treats that line as a proposition to test through Thioamide, class and chemical, not as a finished interpretation.
Why this record matters
The phrase “class of chemical compounds” supplies a clear boundary for inquiry. It also exposes the unanswered questions: who defined that boundary, when it became stable and which sources sit outside it.
The date and method of observation matter as much as the stated conclusion, especially where classification or consensus has changed. The source revision retrieved here is dated Aug 5, 2026. The linked authority identifier is Q419481. None of the 0 selected statements returned an explicit reference.
A general summary may omit uncertainty, sample limits or methodological disagreement that is explicit in the technical record. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Check terminology, classification and the date of the cited evidence. Scientific names and technical consensus can change while older records retain historical value.
- Current terminology
- Classification context
- Finding cited technical literature
Primary datasets, specimen catalogues, standards bodies and the most recent peer-reviewed literature.
Three-step research path
- Establish the record: confirm the title “Thioamide”, its source revision and the description used here.
- Expand the search: follow Thioamide primary sources, Thioamide archive and Thioamide research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Thioamide”?
- Which observation, specimen, dataset or publication supports the account?
- Is the terminology current, historical or disputed?
Search terms from this dossier
This entry incorporates text from “Thioamide” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.