Org. Synth. 1930, 10, 10
DOI: 10.15227/orgsyn.010.0010
BENZOPHENONE OXIME
Submitted by Arthur Lachman
Checked by C. R. Noller
1. Procedure
A mixture of
100 g. (0.55 mole) of benzophenone (Org. Syn. Coll. Vol. I, 1941, 95),
60 g. (0.86 mole) of hydroxylamine hydrochloride (Org. Syn. Coll. Vol. I, 1941, 318),
200 cc. of 95 per cent ethyl alcohol, and 40 cc. of water is placed in a
2-l. round-bottomed flask. To this is added in portions, with shaking,
110 g. (2.75 moles) of powdered sodium hydroxide. If the reaction becomes too vigorous, cooling with tap water may be necessary. After all the
sodium hydroxide has been added, the flask is connected to a
reflux condenser, heated to boiling, and refluxed for five minutes. After cooling, the contents are poured into a solution of
300 cc. of concentrated hydrochloric acid in 2 l. of water. The precipitate is filtered with suction, thoroughly washed with water, and dried
(Note 1). The yield is
106–107 g. (
98–99 per cent of the theoretical amount) of a product melting at
141–142°. On crystallizing
20 g. from
80 cc. of methyl alcohol,
13 g. of crystalline material of the same melting point is obtained
(Note 2).
2. Notes
1.
This crude material dried overnight at about 40° is practically pure and if used at once is satisfactory for the preparation of
diphenylmethane imine hydrochloride (p. 234).
2.
In the presence of
oxygen and traces of moisture,
benzophenone oxime is gradually converted into a mixture of
benzophenone and nitric acid.
1 A good method of preserving this oxime is to dry it in a
vacuum desiccator, fill the desiccator with pure
carbon dioxide, re-evacuate, and fill again with
carbon dioxide. The preparation may then be transferred to a
bottle, also filled with
carbon dioxide, and sealed against access of air.
3. Discussion
Benzophenone oxime has been prepared in quantity by treating an aqueous alcoholic mixture of
benzophenone and
hydroxylamine hydrochloride with
hydrochloric acid,
2 with
sodium carbonate,
3 with alcoholic
potassium hydroxide,
4 or with aqueous
sodium hydroxide.
5 It has also been obtained by treating
bisnitrosylbenzohydryl with alcoholic
potassium hydroxide,
6 and by the oxidation of
α-aminodiphenylmethane with
magnesium persulfate solution.
7
This preparation is referenced from:
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
bisnitrosylbenzohydryl
ethyl alcohol (64-17-5)
hydrochloric acid (7647-01-0)
methyl alcohol (67-56-1)
sodium hydroxide (1310-73-2)
nitric acid (7697-37-2)
sodium carbonate (497-19-8)
oxygen (7782-44-7)
carbon dioxide (124-38-9)
potassium hydroxide (1310-58-3)
Benzophenone (119-61-9)
Hydroxylamine hydrochloride (5470-11-1)
Benzophenone oxime (574-66-3)
diphenylmethane imine hydrochloride (5319-67-5)
α-aminodiphenylmethane (91-00-9)
magnesium persulfate
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