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Org. Synth. 1933, 13, 66
DOI: 10.15227/orgsyn.013.0066
α-METHYL-α-PHENYLHYDRAZINE
[Hydrazine, 1-methyl-1-phenyl-]
Submitted by W. W. Hartman and L. J. Roll.
Checked by Louis F. Fieser and J. T. Walker.
1. Procedure
A mixture of 200 g. (3.1 gram atoms) of zinc dust and 300 cc. of water is placed in a 2-l. three-necked flask equipped with an efficient mechanical stirrer, a thermometer, and a dropping funnel. The suspension is then stirred vigorously while a solution of 100 g. (0.73 mole) of N-nitrosomethylaniline (p. 460) in 200 cc. (210 g., 3.5 moles) of glacial acetic acid is added in a slow stream. The temperature is maintained between 10° and 20° by external cooling or by the addition of finely crushed ice. When all the acid solution has been added (about one and one-half to two hours is required, depending upon the rate of cooling) the mixture is stirred for an hour longer at room temperature and then warmed to 80° on the steam bath. The hot solution is filtered from the unreacted zinc, which is washed with three 100-cc. portions of a warm 5 per cent hydrochloric acid solution. The combined filtrate and washings are cooled and treated with sufficient 40 per cent sodium hydroxide solution to redissolve the zinc hydroxide precipitated. (About 1.2 l. is required.) The oily layer is separated and the aqueous layer extracted with two or three 100-cc. portions of ether. The combined oil and extracts are distilled from a steam bath until the ether is removed; the residue is then distilled under reduced pressure. The yield of colorless (Note 1) α-methyl-α-phenylhydrazine boiling at 106–109° 13 mm. is 46–50 g. (52–56 per cent of the theoretical amount).
2. Notes
1. α-Methyl-α-phenylhydrazine darkens on standing.
3. Discussion
α-Methyl-α-phenylhydrazine has been obtained by reducing nitrosomethylaniline with zinc and acetic acid1 or electrolytically;2 by reducing N-methylnitroformaldehyde phenylhydrazone with zinc and acetic acid;3 by heating methylbenzoylphenylhydrazine with concentrated hydrochloric acid;4 and by methylating phenylhydrazine with sodamide and methyl iodide.5

References and Notes
  1. Fischer, Ann. 190, 152 (1878); 236, 198 (1886).
  2. Wells, Babcock, and France, J. Am. Chem. Soc. 58, 2630 (1936).
  3. Bamberger and Schmidt, Ber. 34, 591 (1901).
  4. Tafel, ibid. 18, 1744 (1885).
  5. Grammaticakis, Compt. rend. 210, 303 (1940).

Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)

α-Methyl-α-phenylhydrazine

N-methylnitroformaldehyde phenylhydrazone

hydrochloric acid (7647-01-0)

acetic acid (64-19-7)

ether (60-29-7)

sodium hydroxide (1310-73-2)

Phenylhydrazine (100-63-0)

zinc (7440-66-6)

Methyl iodide (74-88-4)

Hydrazine, 1-methyl-1-phenyl- (618-40-6)

N-Nitrosomethylaniline,
nitrosomethylaniline

zinc hydroxide (20427-58-1)

methylbenzoylphenylhydrazine

sodamide (7782-92-5)