Ortho-para-isomerism in the preparataion of diaminodiphenylmethane / by Harold King.

  • King, Harold
Date:
1920.]
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Licence: Public Domain Mark

Credit: Ortho-para-isomerism in the preparataion of diaminodiphenylmethane / by Harold King. Source: Wellcome Collection.

    2/6 (page 989)
    under reduced pressure, yielding 33 grains of crude diamino- diphenylmethane, which boiled at 236—240°/11 mm. From A nhydroformaldehydeamline.—One hundred grams of solid anhydroformaldehydeaniline, 249 c.c. of aniline, 43 o.c. of water, and 130 c.c. of concentrated hydrochloric acid were mixed and heated on the water-bath for twelve hours. The crude, dis¬ tilled aniline-free base boiled at 238—242°/15 mm., and amounted to 148'5 grams. Nitration of Diaminodiphenylmethane and Isolation of 4 -Nitro- 2:4'-diaminodiph enylmet hane. Fifty grams of distilled diaminodiphenylmethane were nitrated by Benda’s method (Ber., 1912, 45, 1787). The crude nitration product was collected and extracted once when dry with a limited volume of boiling alcohol. The insoluble solid consisted of 2 : 2/-dinitro*-4 :4'-diaminodiphenylmethane, and amounted to 60-5 grams, which is 83 per cent, of the theoretical yield. As the material soluble in alcohol could not be* purified by further crystal¬ lisation, the solution was evaporated to dryness, and the residual solid, amounting to 14 A grams, dissolved in hot 10 per cent, hydro¬ chloric acid solution and fractionally precipitated by addition of 10 per cent, solution of ammonia. After removal of tarry matter, further addition of ammonia to the hot solution caused the separation of a crystalline precipitate, and eventually a point was reached at which a turbidity developed, due to the incipient form¬ ation of an oil. The crystalline material was collected, and con¬ sisted of 6'3 grams of almost pure 2:2/-dinitro*-4:4/-diaminodi- phenylmethane. The filtrate was now completely precipitated with ammonia, and, when cold, the crude 4-nitro-2 :4/-diamino¬ diphenylmethane (4*3 grams) was collected. The total yield of dinitro-base was about 92 per cent., and of the crude mononitro- base 7 per cent. Another experiment, in which Ehrlich and Bauer s method {Ber., 1915, 48, 502) of nitration was employed, furnished a 10 per cent, yield of crude mononitrodiaminodiphenylmethane. k-Nitro^ : 41 -diaminodiphenylmethane dissolves in about twenty- three parts of boiling alcohol, and crystallises in glistening, orange needles melting at 157—158° (corr.) (Found: C = 64-4; H —5*5. C13H1302N3 requires C = 64‘2; H = 5'4 per cent.). The dihydrochloride crystallises in microscopic, hexagonal-shaped leaflets melting and decomposing at 262° (corr.) (Found: Cl = 22-3. C13H1302N3,2HC1 requires Cl = 22*4 per cent.). The diacetyl derivative crystallises from acetic anhydride or