About: http://webisa.webdatacommons.org/446396758

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	R1 and R2, independently of one another, are a hydrogen atom, a halogen atom, a C1 -C4 -alkyl group or a C6 -C10 -aryl group, preferably an alkyl group or a halogen atom, in particular a chlorine atom;
http://www.w3.org/ns/prov#wasQuotedFrom	google.fr