Appeal No. 2006-2247
Reexamination Nos. 90/006,554 and 90/006,894
1 0.1% of the amine on a molar basis - will be sufficient...” (Column 4, lines 69-74.)
2 Witman further states that the hydrogen peroxide may be in the form of an aqueous
3 solution containing from about 10% to about 90% by weight of hydrogen peroxide.
4 (Column 5, lines 5-7.) Witman also discloses that the reaction medium containing
5 an aqueous solution of hydrogen peroxide may contain an additional solvent
6 (preferably miscible with water) and that, when the amine is a heterocylic amine,
7 the most useful solvents are lower aliphatic carboxylic acids, preferably glacial
8 acetic acid. (Column 5, line 71 to column 6, line 5.) Witman describes the
9 recovery of the N-oxide product as follows:
10 Where a solvent was used, in many cases the solvent too may be
11 removed by distillation. It must be noted that in a great many cases
12 the N-oxide is somewhat unstable, so that distillation of the water or
13 water and solvent must be accomplished at such a low pressure that
14 the N-oxide product is not decomposed. It has been found that in a
15 great percentage of cases, the hydrohalide (e.g., hydrochloride) of the
16 N-oxide is more stable than is the N-oxide itself. In such cases, the N-
17 oxide is best recovered by first converting it to the hydrohalide , then
18 removing water or water and solvent. Also, the N-oxide hydrohalides
19 usually are crystalline, whereas the N-oxides are not; conversion of
20 the N-oxide to the hydrohalide thus provides a simple technique for
21 obtaining a pure product by recrystallization techniques. [Column 7,
22 lines 38-52.]
23
24 In Example V, Witman describes a process in which: (a) 31.6 parts of
25 pyridine, 20 parts water, and 5.0 parts of molybdic anhydride were mixed together
26 and heated to 60°C; (b) 32.8 parts of 50% by weight hydrogen peroxide was added
27 over a ten minute period; (c) the temperature of the reaction mixture was
21
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