Phenyl-substituted cyclic enaminones

Fischer etal, US Patent 6,455,472 (September 24, 2002) Assignee Bayer Aktiengesellschaft Utility Pesticide 

2-Ethoxypyrroline (1.2 g), 4-chlorobenzoylacetonitrile (1 g) and 20 ml toluene were heated to 100°C 1 hour and ethyl alcohol azeotropically distilled off. The mixture was cooled, crystals precipitated upon the addition of hexane, and the product isolated in 74% yield, mp= 156-158 °C. 

At 0°C, the product from Step 1 (1 g) was dissolved in 10ml THF, NaH (0.3 g, 60% pure) added, and the mixture warmed to 20°C 2 hours. Thereafter, chlorobenzoyl chloride 

The reagent of Step 1 and derivatives were prepared by reacting pyrrolidine with triethoxyoxonium tetrafluoroborate (Meerwin s salt) and is described (1). 

Cyclic enaminones of the current invention were also prepared by reacting benzoyl-acetonitrile with methylpyrrolidone with triphosgene as described by the author and illustrated in Eq. 1  

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