Appeal No. 2002-0440
Application 09/113,547
Feist discloses a method for making a carboxylic ester by
reacting a carboxylic acid bromide or (preferably) a carboxylic
acid chloride with an alcohol in the presence of a catalytic salt
which preferably is an onium salt (col. 2, lines 29-63; col. 3,
lines 62-63; col. 4, lines 10-11). “Advantageously, the molar
ratio of alcohol to carboxylic acid halide is between 0.9:1 and
1.1:1, or if the alcohol also serves as a solvent, up to 5:1"
(col. 3, lines 51-54). Like Braun’s method, Feist’s method is
particularly well suited for preparing esters of trifluoroacetic
acid or chlorodifluoroacetic acid using an alcohol which can be
methanol or ethanol (col. 3, lines 42-46). In Feist’s example 9,
a clear yellow solution containing methyl chlorodifluoroacetate
is produced by reacting 1.0 mole methanol with 1.0 mole
chlorodifluoroacetyl chloride. In Feist’s example 10, ethyl
chlorodifluoroacetate is produced by reacting 1.0 mole ethanol
with 1.0 mole chlorodifluoroacetyl chloride. “After addition of
0.5 mole of the acid chloride, a strong turbidity (phase
formation) was observed in the reaction solution, which upon
Page: Previous 1 2 3 4 5 6 7 8 9 Next
Last modified: November 3, 2007