Selecting Wikipedia articles by InChI

  1. Using dbpedia + SPARQL:
    SELECT DISTINCT ?compound WHERE {  
      ?compound a <> .
      ?compound <> ?section .
      ?section <> "1/C6H3Cl3/c7-4-1-2-5(8)6(9)3-4/h1-3H"@en
  2. In theory, using WikiXMLDB (Sedna) + XQuery:
    declare default element namespace "";  
    declare ordering unordered; 
    doc("wiki")/mediawiki/page/revision/text/template[@head="Identifiers"]/field[@name="InChI"][. = "1/C6H3Cl3/c7-4-1-2-5(8)6(9)3-4/h1-3H"]
    but it times out due to lack of indexes (probably).
  3. Convert the InChI to a ChemSpider ID, then look up external references for that internal identifier:
  4. As Egon points out in the comments, provides a linking/metadata service for compounds (doesn't seem to work if the InChI is URL-encoded):

The infoboxes in Wikipedia don't seem to be using Standard InChIs yet - i'll be good if they can be updated programmatically from ChemSpider.