Patent ID: 7772409

Claim:
A method of preparing a sultine of formula (V) from a dihalogeno compound of formula (IV) said method comprising the steps of: reacting said dihalogeno compound (IV) with a hydroxymethanesulfinate salt in a DMSO solvent so as to prepare said sultine (V); and reacting said sultine (V) with maleic anhydride at elevated temperature to generate tetrahydronaphthalic anhydride as a Diels-Alder adduct, wherein: R 1 , R 2 , R 3 and R 4 are each independently selected from the group consisting of: hydrogen, hydroxyl, C 1-20 alkyl, C 1-20 alkoxy, amino, C 1-20 alkylamino, di(C 1-20 alkyl)amino, halogen, cyano, thiol, C 1-20 alkylthio, nitro, C 1-20 alkylcarboxy, C 1-20 alkylcarbonyl, C 1-20 alkoxycarbonyl, C 1-20 alkylcarbonyloxy, C 1-20 alkylcarbonylamino, C 5-20 aryl, C 5-20 arylalkyl, C 5-20 aryloxy, C 5-20 arylalkoxy, C 5-20 heteroaryl, C 5-20 heteroaryloxy, C 5-20 heteroarylalkoxy and C 5-20 heteroarylalkyl; and X is selected from the group consisting of: Cl, Br and I.