Patented Mar.

27, 1934
1952,591
PATENT OFFICE
1952,591
METHOD FOR PRODUCING DAZOD
NROPHENO
Roy. S. Hancock and Leslie C. Pritchett, Kenvil,
N.J., assignors to Hercules. Powder Company,
Wilmington, Del, a corporation of Delaware
No Drawing. Application July 1, 1932,
. Serial No. 620,529
5 Claims. (CL 260-69)
This invention relates to a method for the diazotization of the picramate and nitrite, as,
production of diazodinitrophenol and more par for example, hydrochloric acid or equivalent
ticularly to a method whereby diazodinitro amounts of sulphuric, phosphoric, acetic, etc.
phenol may be produced directly in a free-flowing acids...
5 form. In carrying out the method the picramate and
Diazodinitrophenol has been known hereto the nitrites will be in solution or in Suspension,
fore and methods for its production have been or partly, in solution and partly in Suspension in
disclosed. . . Thus, for example, dia2Odinitro water. Thus, for example, a suspension of so
phenol and a method for its production are dis dium picramate with a concentration as high as
10 closed in the United States Patents to Dehn Nos. 9.7% has been successfully diazotized by the
1,404,687, 1428,011 and 1,460,708. The com method of this invention Without indication that
pound constitutes a very valuable detonating ma the figure is in any Way limiting. The Solution
terial for use, for example, in charging blasting or SuSpension will desirably be substantially neu
caps. However as directly produced by methods tral, and the concentration of the Salts, while
is heretofore known, it is not free-flowing and they may Wary Widely, will be Such desirably as
hence cannot be readily loaded. to give efficient and economic results. The tem
Now in accordance with this invention a novel perature during the diazotization will be con
method is provided for the production of diaZO trolled and Will desirably be maintained, by any
dinitrophenol and one in its more specific em Suitable means, within about the range 10-16 C.
20 bodiment by which free-flowing diazodinitro Where the acid is added gradually for the pro 's
phenol may be prepared directly. duction of diaZOdinitrophenol in a free-flowing
Having now indicated in a general Way the form, the addition will be at a relatively slow
nature and purpose of this invention, We Will rate, Say, for example, at the rate of about 0.001.
proceed to a more detailed description thereof grams HCl per minute per gram of Sodium
25 from the broad and from the more specific picramate, or at equivalent rates for other acids 80
StandpointS. and/or other picramates. AS Will be understOOd,
From the broad standpoint the method em however, the most desirable rate of addition of
bodying this invention involves the diazotization the acid in any given case will depend upon the
of a salt of picramic acid by a Salt of nitrous temperature and other Variables, but will readily
30 acid and an acid. Thus broadly, this invention be determined in a given case by those Skilled 85
involves the diazotization of a picramate by a in the art. Alternative to adding all of the acid
nitrate and an acid. gradually a part, Say about 25%, may be added
More specifically, and especially where the rapidly and the balance added gradually.
direct production of diaZOdinitrophenol in a As illustrative of the practical application of
35 free-flowing form is desired, the acid will be the method in accordance With this invention, 90
added gradually at a Siow rate, or a portion of for example, about 6.2 pounds (dry Weight) of
the acid may be added rapidly at the Start With Water wet sodium picramate, from Which foreign
gradual addition of the balance. The rate of material has been removed, as by Screening, Say
addition of the acid, where Such is added grad through a 40 mesh, Screen, is charged into a
40 ually, following the more specific procedure in Wooden diazotization. tub, fitted with an agitator, 95
accordance with this invention, will depend upon With about 90 gallons of Water. About 19 pounds
temperature and other variables obtaining dur of Sodium nitrite dissolved in 10 gallons of Water
ing the addition. are then run into the tub and the agitator started.
In the practical adaptation of this invention The temperature is adjusted, by any Suitable
45 any suitable salt of picranic acid, Or picramate, means, for example, by the addition of ice to 00
may be used. Thus, for example, Sodium say about 15° C. About 40 liters of 1:1 hydro
picramate, ammonium picramate, magnesium chloric acid are then added, preferably at a rate
picramate, etc., may be used, one being Substitut Such as to require about 300 minutes for the
able for the other in equivalent quantities. addition of the acid. During the course of the
50 Likewise, various Salts of nitrous acid, or run the temperature is maintained at about 05
nitrites, may be used, Such, for example, as 15-16 C. by suitable means, as by the addition
SOdium nitrite, potassium nitrite, barium nitrite, of ice as required. About five minutes after
etc., being used in Substitution for One another in completion of the addition of the acid the solu
equivalent quantities. tion is tested with, for example, potassium iodide
55 The acid may be any suitable acid for effecting starch paper and if a strong positive test is ob O
 2 1,952,591
tained an excess of nitrous acid in the solution
1. The method for producing diazodinitro
is indicated which shows that the diazotization phenol in a free flowing form which includes
of the sodium picramate has been completed. diazotizing a picramate by the gradual addition of
The agitation is then stopped and the charge an acid thereto in the presence of a nitrite and
dumped, for example, into a Suction filter, the Water. 80
mother liquor drawn off and the diazodinitro 2. The method for producing diazodinitro
phenol Washed With Water to free it from im phenol in a free flowing form. Which includes
purities. .
gradually adding an acid to a Substantially neu
. . . . . . .

Following the above procedure the diazodi tral mixture of a Salt of picramic acid and a salt
O initiophenol produced will be in free-flowing form of nitrous acid and water. 85
without any subsequent treatment and free-flow
iing diaZOdinitrophenol may be obtained by vary
3. The method for producing diazodinitro
phenol in a free flowing form which includes
ing the above procedure to an extent by adding diazotizing a picramate by the gradual addition
part of the acid, say for example, 10 liters, quickly. of an acid thereto in the presence of a nitrite and
5 at the start with gradual addition of the balance. water while maintaining the temperature of the 90
Where the diazodinitrophenol is not desired in a reagents within about the range 10-16 C.
free-flowing form the acid may be added without 4. The method for producing diazodinitro
any special attention to the rate of addition. phenolin a free flowing form which includes
As has been indicated, the procedure given in gradually adding an acid to a Substantially neu
20 the above illustration by Way of example, may be tral mixture of sodium picramate and Sodium 95
widely varied without departing from this in nitrite in water.
vention. Likewise, various picramates, nitrites 5. The method for producing diazodinitro
and acids may be used in varying proportions and phenol in a free flowing form which includes.
the conditions of diazotization, as temperature, gradually adding an acid to a substantially neu
etc. may be widely varied within operative limits. tral mixture of a Salt of picramic acid and a salt 90
As will be obvious, the method in accordance of nitrous acid in water while maintaining the
With this invention is not dependent upon the use temperature of the reagents within about the
of any particular form of apparatus, means for range 10-16 C.
cooling, or the like. - -
ROY S. HANCOCK.
What we
Patent is:
claim and desire to protect by Letters LESLIE C. PRITCHETT. 195

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