Appeal No. 2006-2428 Page 3
Application No. 10/362,500
which is unsubstituted or substituted by R4 or together are an alkylene bridge having
two or three carbon atoms which optionally contains a hetero atom selected from the
group consisting of NR5, O and S,
R3 is H or C1-C12 alkyl which is unsubstituted or substituted by R4,
R4 is unsubstituted or substituted aryl or heteroaryl, and
R5 is H or C1-C12 alkyl.
The specification states that SO2Cl2, or sulfuryl chloride, is advantageous as the
chlorinating agent because “more material can be prepared in the same unit of time
than when Cl2 is employed, certain waste substances are produced in significantly
smaller amounts by that means, and there are further advantages besides.” Pages 2-3.
However, “[t]he known preparation processes are . . . not satisfactory in every respect,
which is why there is a need to provide improved preparation processes for the
compounds of formula (I) and especially of formula (III).” Page 2.
Specifically, the use of SO2Cl2 as the chlorinating agent for converting the
compound of formula (II) to the compound of formula (III) is said to “ha[ve] the
significant disadvantage that stoichiometric amounts of SO2 are produced, which have
to be removed, either by recycling the SO2 to SO2Cl2 using Cl2 or by having to convert
the SO2 into SO42- by oxidation.” Page 3. According to the specification, SO42- is an
undesirable waste product because it “attacks the concrete walls of waste water
purification systems. . . . The conversion of SO2 to SO2Cl2 using Cl2, on the other hand,
naturally requires a specific production system to be set up.” Id.
The specification discloses methods which maintain the yield advantages of
using sulfuryl chloride as the chlorinating agent, while avoiding the waste problems
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