The plaintiffs, FMC Corporation and FMC Agro Singapore Pte Ltd (FMC), sought an interim injunction against the defendant, Insecticides India Limited (IIL). The plaintiffs asserted that IIL had used their patented processes to prepare anthranilic diamide insecticide compounds covered by Indian patent No. 298645 (the 645 patent). The 645 patent had been assigned to FMC by EI du Pont de Nemours and Company.
FMC alleged that IIL’s process was substantially similar to FMC’s. It contended that while IIL’s process utilised the carboxylic acid of formula two and the aniline compound of formula three, instead of the sulfonyl chloride, IIL employed thionyl (oxalyl) chloride. Further, IIL’s use of oxalyl chloride instead of sulfonyl chloride was an insubstantial difference. According to FMC, the two performed the same function (ie, activation of a carboxylic acid moiety) in the same way as the coupling of the carboxylic acid with aniline to achieve CTPR. Thus, the two manufacturing processes were equivalent.