Oxime Derivatives and Their Use Thereof as Latent Acids

Patent Oxime Derivatives and Their Use Thereof as Latent Acids 

Asakura etal, US Patent 6,512,020 (January 28, 2003) Assignee Ciba Specialty Chemicals Utility Photoresist Latent Acid for Acid-Curable Resins 

2-Trifluoro-l-phenyl-ethanone (25 g) was dissolved in ethyl alcohol at 80 °C and hydroxylamine oxime (0.151 mol) and sodium acetate (0.245 mol) dissolved in 20 ml water added. The mixture refluxed overnight and was then concentrated. The residue was poured into water and a white precipitate isolated and directly in Step 2. 

2-Trifluoro-l-phenyl-ethanone-oxime-O-(10-camphoryl-sulfonate) 

The product from Step 1 (10.6 mmol) was dissolved in 40 ml THE, cooled in an ice bath, and 10-camphoryl chloride (11.6 mmol) and triethylamine (15.9 mmol) added. The reaction was stirred at 0°C 3 hours, poured onto ice, and the product extracted with EtOAc. The organic phase was washed with water and brine, dried, and concentrated. The mixture was purified by flash chromatography on silica gel using EtOAc/hexane, 9 1, and the product isolated in 52% yield as Z/E isomers, 9 1, respectively. H-NMR data supplied. 

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