| abstract |
The invention provides novel processes for preparing efficiently compounds of general formula (I) (wherein R1 and R2 are each independently hydrogen, optionally substituted C1-C10 alkyl, C3-C14 hydrocarbyl bearing an alicyclic skeleton, or the like) and intermediates thereof. Compounds of general formula (I) can be prepared by subjecting compounds of general formula (II) and/or salts thereof to cyclization hydrolysis in an aqueous basic solution. Further, compounds of general formula (II) can be prepared from industrially easily available diaminomaleonitrile in a high yield. |