2,4-Dimethylphenylhydrazine hydrochloride synthesis

Yield:60480-83-3 35.8%

Reaction Conditions:

Stage #1:2,4-Xylidine with hydrogenchloride;sodium nitrite in water at 0 - 5;
Stage #2: with tin(ll) chloride in water at 5;

Steps:

13
Example 13, Preparation of 2.4-xylylhydrazine hydrochloride (compound 13) To a mixture of 2.4-dimethylaniline (35.4 mL; 36.3 g; 0.3 mole) and concentrated hydrochloric acid (220 mL) chilled to 0°C, the solution of sodium nitrite (20.6 g; 0.3 mole) in water (60 mL) was added dropwise at such a rate to maintain reaction temperature not higher than 5°C. Then, the solution prepared was filtered off and added to a solution of stannous chloride (124 g; 0.65 mole) in concentrated hydrochloric acid (124 mL) chilled to 5°C, while vigorous stirring. The precipitate formed was separated by filtration, slurried in water (500 mL), and alkalized to pH 12 with solution of sodium hydroxide (440%). The reaction mixture was extracted with diethyl ether (3*200 mL). Ethereal extracts were dried over MgSO₄. Then, a stream of dried hydrogen chloride was bubbled via the ethereal solution of p-tolyl hydrazine. The precipitate formed was filtered, washed with ether, and dried in vacuum desiccator over P₂O₅. 2.4-Xylylhydrazine hydrochloride (compound 13) was obtained with yield of 18.5 g (35.8%). λ_max 281 nm. Mass-spectrum (MALDI) (C₈H₁₂N₂): found m/z 137.2, calculated m/z 136.19. ¹H- NMR (D₂O), δ (ppm): 2.03 (3H, s, p-CH₃), 2.08 (3H, s, -CH₃), 6.72 (1H, s, ArH), 6.93 (2H, d, ArH)

References:

UCHREZHDENIE ROSSIISKOI AKADEMII NAUK INSTITUT MOLEKULYARNOI BIOLOGII IM. V.A. ENGELGARDTA RAN (IMB RAN) EP2157088, 2010, A1 Location in patent:Page/Page column 43-44

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