Process for preparation of 4-(1-(4-(perfluoroethoxy)phenyl)-1H-1,2,4-triazol-3-yl)benzoyl azide
View Patent ↗By either forming a triaryl acid halide or a triaryl mixed anhydride and subsequently treating with aqueous sodium azide, triaryl acyl azides are prepared in high yield using inexpensive reagents in a process in which by-products are easily removed from the triaryl acyl azide.
1. A process for preparing triaryl acyl azides of the Formula (I),
wherein
R 1 represents (C 1 -C 6 ) haloalkyl or (C 1 -C 6 ) haloalkoxy,
which comprises
a) contacting a triaryl acid of Formula (II)
wherein
R 1 is as previously defined,
with chlorocarbonate of Formula (IV)
wherein
R 2 represents (C 1 -C 6 ) alkyl, phenyl or benzyl,
in the presence of a base in an organic solvent that is tetrahydrofuran or dimethoxyethane to provide a triaryl mixed anhydride of Formula (V)
wherein
R 1 and R 2 are as previously defined, and
b) contacting the triaryl mixed anhydride of Formula (V) with an aqueous solution of sodium azide in the organic solvent tetrahydrofuran or dimethoxyethane.
2. The process of claim 1 in which R 1 is OCF 2 CF 3 .
3. The process of claim 1 in which R 2 is CH 2 CH 3 .
4. The process of claim 1 in which the base is an alkali metal carbonate, a tertiary amine or an aromatic amine.