O-Acyloxime photoinitiators

Matsumoto etal, US Patent 6,596,445 (July 22, 2003) Assignee Ciba Specialty Chemicals Utility Photopolymerization Initiators 

Sodium methoxide (0.206 mol) was suspended in 130 ml methyl alcohol and isoamyl nitrite (0.206 mol) and l-(4-methylsulfanyl-phenyl)-butan- 1-one dissolved 70 ml THF added. The solution was stirred at ambient temperature 2 days, eoncentrated, then neutralized with HO Ac. The mixture was extracted with EtOAc, washed, dried, purified by chromatography on silica using EtOAc/hexane, 15 85, and the product isolated. H-NMR data supplied. 

l-(4-Methylsulfanyl-phenyl)-butan-l,2-dione-2-oxime-0-acetate 

The product from Step 1 (15.7 mmol) was dissolved in 20 ml THE and cooled in an ice bath. Thereafter, acetyl chloride (17.3 mmol) and triethylamine (23.6mmol) were successively added, the reaction stirred 1 hour, and the mixture poured into water. The product was extracted with EtOAc, purified by chromatography on silica gel using EtOAc/hexane, 20 80, and the product isolated. H-NMR data supplied. 

Photoinitiators of the current invention become activated in the region between 190 and 600 nanometers. 

---