173601-76-8Relevant academic research and scientific papers
Pesticides labelled with 14C. II. Synthesis of propiconazole labelled in three different positions
Koltai,Kling,Rutkai
, p. 903 - 908 (1995)
Propiconazole was labelled with 14C m three different positions: in the benzene ring, in the position 5 of the dioxolane ring, and in the triazole ring. The synthesis of three new key intermediates (m-dichloro[U-14C]benzene], 1,2,4-[
The synthesis of [U-14C phenyl] LS 840606, an agricultural fungicide
Madegard,Mestre,Raimond,Noel
, p. 1123 - 1132 (2007/10/03)
2,2',4'-Trichloro-[ring U-14C]acetophenone 3 was the key intermediate of this synthesis patterned after the industrial route. An unexpected poor yield was observed during the preparation of 3 by the Friedel-Crafts reaction of chloroacelyl chloride with 1,3-dichloro-[U-14C]benzene 10, possibly the result of an isotope effect although this poor yield might be explained by other factors. Two routes ware checked for the preparation of 1,3-dichloro-[U-14C]benzene 10. The action of CCl4 with 1,3-dinitro-[U-14C]benzene at 280°C was entailed with explosions. A safer route started from [U-14C]aniline via 2,4-dichloro-[ring U-14C]acetanilide, Friedel-Crafts reaction of 10 with acetyl chloride gave rise in 52% yield to 2',4'-dichloro-[ring U-14C]acetophenone 16 which was brominated to 2-bromo-2',4'-dichloro-[ring U-14C]acetophenone 17; 17 was condensed with 2,2-(ethylenedioxy)ethylmagnesium bromide to compound 18; 18 was condensed with 1,2,4-triazole to 5 then successively treated with HCl:water:dioxane and 2,2,2-trifluaroethanol/HCl. Separation of the two diastereomers by medium pressure liquid chromatography. 7% overall radioactive yield from [U-14C]aniline. Radiochemical purity 99%.
