Appeal No. 2006-2247
Reexamination Nos. 90/006,554 and 90/006,894
1 amine reactant charged, will effectively catalyze the reaction between
2 the amine and the hydrogen peroxide” and in “many cases, even less
3 of the catalyst - e.g., as little as 0.1% of the amine on a molar basis -
4 will be sufficient...” (Column 4, lines 69-74.)
5 24. Witman further states that the hydrogen peroxide may be in the form
6 of an aqueous solution containing from about 10% to about 90% by
7 weight of hydrogen peroxide. (Column 5, lines 5-7.)
8 25. Witman also discloses that the reaction medium containing an
9 aqueous solution of hydrogen peroxide may contain an additional
10 solvent (preferably miscible with water) and that, when the amine is a
11 heterocylic amine, the most useful solvents are lower aliphatic
12 carboxylic acids, preferably glacial acetic acid. (Column 5, line 71 to
13 column 6, line 5.)
14 26. Witman describes the recovery of the N-oxide product as follows:
15 Where a solvent was used, in many cases the solvent too may
16 be removed by distillation. It must be noted that in a great
17 many cases the N-oxide is somewhat unstable, so that
18 distillation of the water or water and solvent must be
19 accomplished at such a low pressure that the N-oxide product is
20 not decomposed. It has been found that in a great percentage of
21 cases, the hydrohalide (e.g., hydrochloride) of the N-oxide is
22 more stable than is the N-oxide itself. In such cases, the N-
23 oxide is best recovered by first converting it to the hydrohalide,
24 then removing water or water and solvent. Also, the N-oxide
25 hydrohalides usually are crystalline, whereas the N-oxides are
8
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