G. Patrick Stahly

Nucleophilic addition of difluoromethyl phenyl sulfone to aldehydes and various transformations of the resulting alcohols

Abstract Nucleophilic addition of difluoromethyl phenyl sulfone ( 1 ) to various aldehydes occurred in a two phase system (50% aqueous sodium hydroxide, dichloromethane. Aliquat® 336) to give difluoro(phenylsulfonyl)methyl substituted alcohols ( 2 /2 8 ). The product alcohol derived from para -tolualdehyde was converted to the difluoromethylated alcohol by desulfonylation and to the α, β, β-trifluorostyrene by a fluorination-elimination sequence. In the absence of aldehydes, 1 reacted in the two phase system to give difluoro(phenylsulfonyl)methyl phenyl sulfide ( 9 ). The pathway of the latter conversion was studied.

Optical purification of profen drugs

Abstract Ibuprofen ( 1 ) and naproxen ( 2 ) are optically purified by crystallization of their sodium salts ( 3 and 4 ) from optically enriched mixtures. Treatment of an acetone solution of 76% ee 1 with NaOH afforded 100% ee 3 . Calculated melting point phase diagrams of compounds 1–4 are presented.

Trifluoromethylation of 1,3,5-trinitrobenzene

Abstract The trifluoromethyl anion was trapped as Meisenheimer complex 2 on heating a mixture of potassium trifluoroacetate and 1,3,5-trinitrobenzene (TNB) in DMF or DMSO. Treatment of 2 with tert -butylhypochlorite afforded 1-trifluoromethyl-2,4,6-trinitrobenzene ( 3 ).

A Diels-Alder Approach to 4,4′-Ihiobis-(Phihalic Acid) Derivatives

Abstract Reactions of 3,3′-thiobis(2,5-dihydrothiophene 1,1 dioxide) (2) with several dienophiles afforded Diels Alder adducts 4–7. Compound 7 was aromatized to give 4,4′-thio-bis(dimethyl phthalate) (9), a potential intermediate to sulfur- bridged polyimides.