Bleach oxidation of N,N'-di-t-octylsulfamide to di-t-octyldiazene

Di-t-octyldiazene is prepared in improved yield, purity and economics by oxidizing N,N'-di-t-octylsulfamide with sodium hypochlorite solution in a strongly basic medium at a temperature of 65.degree.-90.degree. C. in a minimal amount of hydrocarbon or chlorinated hydrocarbon solvent for about 2 to 5 hours until completion of the reaction. The employment of phase transfer catalysts or t-butyl alcohol in the oxidation is optional. Di-t-octyldiazene is used as a polymerization initiator for vinyl monomers and as a curing agent for unsaturated polyester resins.

BACKGROUND OF THE DISCLOSURE 
1. Field of the Invention 
This invention relates to an improved process of preparing 
di-t-octyldiazene by oxidizing N,N'di-t-octylsulfamide with sodium 
hypochlorite and caustic and optionally in the presence of a phase 
transfer catalyst and/or t-butyl alcohol at a temperature of 
65.degree.-90.degree. C. in a minimal amount of solvent. 
2. Prior Art 
Among the many t-azoalkanes (I) known, 
##STR1## 
di-t-octyldiazene (II) is a particularly attractive compound to make 
commercially. 
##STR2## 
Di-t-octyldiazene is a known compound whose rate of thermolysis was 
studied by Timberlake and co-workers (B. K. Bandlish, A. W. Garner, M. L. 
Hodges and J. W. Timberlake, J. Am. Chem. Soc. 97, p.5856-5862, 1975). 
From their thermolysis data the 10 hr. half-life temperature (t1/2) was 
calculated to be about 107.5.degree. C. Thus, its decomposition 
temperature falls into a very useful temperature range for initiating 
vinyl polymerizations. The compound is a liquid at room temperature and is 
relatively non-volatile. Since it does not contain any cyano groups as do 
the commercial symmetrical and unsymmetrical azonitriles, it should not 
generate any toxic residues upon decomposition. Despite the attractiveness 
of this compound, no evidence was found that di-t-octyldiazene (II) is 
being produced or used commercially despite the commercial availability of 
t-octylamine. This is because prior to the present invention there wasn't 
any commercially feasible route to prepare di-t-octyldiazene. 
In 1965 R. Ohme and E. Schmitz developed a general synthetic method for the 
preparation of azoalkanes (R. Ohme and E. Schmitz, Angew Chem Int. Ed. 
Engl. 4, p.433, 1965). They found that the dialkylamides of sulfuric acid 
in a solution of N alkali react with 2 moles of NaOCl at 
20.degree.-60.degree. C., to form aliphatic azo compounds. They prepared 
the low molecular weight azopropane, azobutane, and azocyclohexane in this 
manner. 
In 1967 R. Ohme and H. Preuschof studied the mechanism of this oxidation as 
well as the oxidation of N,N'-disubstituted sulfamides and monosubstituted 
sulfamides (R. Ohme and H. Preuschkof, Liebigs Ann. Chem. 713, p.74-86, 
1968). During the course of their investigation they prepared 
2,2'-azoisobutane in 84% yield by oxidizing N,N'-di-tert-butylsulfamide in 
2N NaOH with 2 equivalents of NaOCl at 60.degree. C. J. C. Stowell 
prepared 2,2'-azoisobutane in 84% yield by running a similar type reaction 
for 3 hours in pentane (J. C. Stowell, J. Org. Chem. 32, p.2360, 1967). 
In 1972 J. W. Timberlake and co-workers attempted to prepare 
di-t-octyldiazene and di-t-heptyldiazene by this route but were 
unsuccessful (J. W. Timberlake, M. L. Hodges and K. Betterton, Synthesis 
1972, p.632-34). Treatment of either 
N,N'-bis[2,4,4-trimethyl-2-pentyl]sulfamide (i.e. 
N,N'-di-t-octylsulfamide) or N,N'-bis[2,3,3-trimethyl-2-butyl]sulfamide 
(i.e. N,N'-di-t-heptylsulfamide) under the conditions specified in Ohme's 
articles gave no azo compound. Timberlake recognized that the oxidation of 
sulfamides to azo compounds was not adaptable to all azos. The conditions 
were too vigorous for isolating unstable azo compounds and solubility 
problems in several cases led to quantitative return of starting 
sulfamides. Therefore Timberlake developed a more complex method of 
converting the N,N'-dialkylsulfamides into azoalkanes. He used a 
completely homogeneous mixture with potassium t-butoxide as the base, 
t-butyl hypochlorite as the chlorinating agent, and t-butanol as the 
solvent. He also developed a heterogeneous mixture with sodium hydride as 
the base and t-butyl hypochlorite as the chlorinating agent in an 
ether/pentane solvent. Timberlake prepared di-t-octyldiazene in 78% yield 
by treating the sulfamide with a slurry of 2 eqs. of sodium hydride in 
pentane for 2 hours at room temperature, the reaction cooled to 0.degree. 
C. and 2 eqs. of t-butyl hypochlorite added dropwise and the mixture 
stirred overnight. The excess sodium hydride was then destroyed by the 
careful addition of water and the pentane solution of the azo 
chromatographed over alumina. The azo was then distilled to obtain a 78% 
yield. Although the process was very useful for preparing laboratory scale 
samples, it was hardly practical for development on a commercial scale. 
In 1974 C. Ruchardt and co-workers proclaimed that they had a new simple, 
high yield procedure for the large scale synthesis of tert-azoalkanes (I) 
from readily available chloroazoalkanes and trialkyl- or triphenylaluminum 
(W. Duismann, H. Beckhaus and C. Ruchardt, Liebigs Ann. Chem. 1974, 
p.1348-1356). Ruchardt stated that the t-azoalkanes are excellent 
generators of free radicals but representatives of this class of compounds 
have still not acquired any significance as initiators in industry solely 
due to the difficulty in preparing them. The known syntheses are tedious 
and frequently produce low yields. None of the known preparative 
procedures are suited to general large-scale synthesis of t-azoalkanes. 
Ruchardt felt his process would overcome these shortcomings. Ruchardt and 
co-workers produced 28 different symmetrical t-azoalkanes by this process. 
They prepared di-t-octyldiazene in 82% yield. 
In 1976 M. Prochazka prepared di-t-octyldiazene by the oxidation of 
t-octylamine with IF.sub.5 (M. Prochazka, Collect. Czech. Chem. Commun. 
1976, 41(5), p.1557-1564 (Eng); C.A. 86, p.338c, 1977). The compound was 
prepared on a small scale for comparison of its rate of decomposition with 
other t-azoalkanes Prochazka prepared. 
In 1978 a Japanese patent described a process for oxidizing 
N,N'-di-t-octylsulfamide with bleach and caustic in the presence of a 
phase transfer catalyst (Japan Kokai 77, 128, 305; C.A. 88, p.120602m, 
1978). The reaction was run at 40.degree. C. and required 10 hours to 
complete. This was the first indication that di-t-ocyldiazene could be 
prepared by the aqueous bleach route. The process required a phase 
transfer catalyst and a long reaction period. 
In early 1982 a European patent (European Pat. No. 0,006,972) was published 
describing a photopolymerization process. In the patent, there is a 
description of the preparation of 2,2'-azobis(2,4,4-trimethylpentane) 
which is also referred to as di-t-octyldiazene. The di-t-octyldiazene was 
prepared by oxidizing N,N'-di-t-octylsulfamide with bleach and caustic 
solution for 20 hours at 35.degree. C. The yield was only 50% after 
purification by vacuum distillation. A complete description of the 
experiment was not provided. However, in other examples in the patent, 
2,2'-azobis-2-methylbutane and 1,1'-di-methyl-azocyclopentane were 
prepared by oxidizing the corresponding sulfamides with sodium 
hypochlorite solution in the presence of 10 parts pentane to 1 part 
t-butyl alcohol. The reactions were stirred for 24 hours at 
35.degree.-40.degree. C. Specific % yields were not reported. 
In 1971 A. Ohno and co-workers reported the preparation of 
azobis-(2-propyl)-2-propane by sodium hyprochlorite oxidation of the 
corresponding sulfamide (A. Ohno, N. Kito and Y. Ohnishi, Bull. Chem. Soc. 
Japan, 1971, 44, p.470-474). The azo was obtained in 38% yield after 
stirring 7.0 grams of the sulfamide in 50 ml of hexane with 150 ml of 10% 
NaOCl for 35 hours at room temperature. The crude product was purified by 
distillation. 
Although these reactions used cheap raw materials, i.e. sodium hydroxide 
and sodium hypochlorite instead of sodium hydride and t-butyl 
hypochlorite, the reaction time required to complete the reaction was much 
too long to be commercially attractive. Therefore, despite the fact that 
di-t-octyldiazene has been made by five various routes, there is no 
commercially attractive route to di-t-octyldiazene. In addition, there is 
no indication that the oxidation of the sulfamide can be carried out in 
high yield and short reaction time using the sodium hypochlorite-sodium 
hydroxide system. In fact the prior art indicates it cannot be done. 
SUMMARY OF THE INVENTION 
This invention is directed to an improved process of preparing 
di-t-octyldiazene comprising oxidizing N,N'-di-t-octylsulfamide with 
sodium hypochlorite (bleach) in a strongly basic solution at a temperature 
of 65.degree.-90.degree. C. in the absence of or in the presence of a 
minimum amount of a hydrocarbon or chlorinated hydrocarbon solvent (i.e., 
less than 4 parts solvent per part sulfamide) for about 2 to 5 hours until 
completion of the reaction. The crude product is given an aqueous sodium 
bisulfite wash to remove chloramine impurities. The improvements in the 
process will make it economically feasible to produce di-t-octyldiazene on 
a commercial scale. 
DETAILED DESCRIPTION OF THE INVENTION 
Since the N,N'-di-t-octylsulfamide is conveniently prepared and isolated in 
a hydrocarbon solvent such as pentane, hexane, cyclohexane, or heptane, 
the solvent content can be reduced to the desired range by evaporation 
under reduced pressure or by distillation, either before the oxidation 
reaction is started or during the course of the reaction. The rate of 
oxidation can be conveniently adjusted so that proper reaction control can 
be maintained by simply adjusting the reaction temperature and the rate of 
solvent removal. From maximum rate of oxidation, it is desirable to reduce 
the solvent to sulfamide ratio to a range of 2:1 to 0.5:1. The reaction 
will occur more rapidly if the solvent is completely removed but this is 
neither necessary nor advantageous. Operating above the 4:1 ratio of 
solvent to sulfamide slows the reaction down considerably and leads to 
lower assay product. 
Although only two equivalents of bleach and one equivalent of caustic per 
equivalent of sulfamide are necessary, it is advantageous to use excess 
bleach and caustic to speed up the reaction and insure complete oxidation 
since these raw materials are relatively inexpensive. Generally a mole 
ratio of 2.5-2.8:1 of bleach to N,N'-di-t-octylsulfamide and a mole ratio 
of 2.0-2.5:1 of caustic to sulfamide work well without being unduly 
wasteful. The excess bleach insures completion of reaction in a reasonable 
amount of time and the excess caustic stabilizes the bleach at the higher 
reaction temperatures. Since the ten hour t1/2 of di-t-octyldiazene is 
about 107.5.degree. C., it is advisable to hold the reaction temperature 
at 90.degree. C. or below to prevent thermal decomposition of the azo that 
forms. Normally, temperatures of 65.degree.-75.degree. C. are adequate for 
oxidizing the N,N'-di-t-octylsulfamide in a short period of time, that is, 
in less than 5 hours with 2 to 4 hours being preferred. 
The starting N,N'di-t-octylsulfamide is prepared from commercially 
available t-octylamine and sulfuryl chloride using either the method of 
Stowell (J. C. Stowell, J. Org. Chem. 32, p.2360, 1967) or of Timberlake 
(J. W. Timberlake, J. Alender, A. W. Garner, M. L. Hodges, C. Ozmeral and 
S. Syilagyi, J. Org. Chem. 46, p.2082-2089, 1981). The reaction is 
preferably run in hexane and the product isolated as a hexane solution. 
The hexane solution of the sulfamide can be concentrated prior to 
oxidizing the sulfamide or it can be concentrated during the oxidation. 
The sulfamide reaction can be run in hydrocarbon or chlorinated hydrocarbon 
solvents. Pentane, hexane, heptane, cyclohexane, and methylene chloride 
are preferred for the reaction. Hexane is the most preferred solvent for 
the reaction because it boils at a desirable temperature for the oxidation 
step and residual hexane can be readily removed from the product by 
stripping under reduced pressure. 
It is desirable to use 14-15% sodium hypochlorite in the oxidation. 
Normally, higher concentrations of bleach are not commercially available. 
Weaker solutions of bleach also work, but smaller batch sizes have to be 
run in a common reactor to accommodate the larger volume of weak bleach 
required. Sodium or potassium hydroxide are suitable bases for maintaining 
the high pH required throughout the course of the reaction but sodium 
hydoxide is preferred on an economical basis. 
The use of phase transfer catalysts and t-butyl alcohol are optional. The 
presence of a small amount of a phase transfer catalyst eliminates foaming 
during the oxidation step. An antifoaming agent would accomplish the same 
end. 
Normally small amounts of N-chloramines form in the oxidation step. 
Therefore, it is advisable to wash the crude azo with sodium bisulfite 
solution to reduce these bothersome impurities back to t-octylamine which 
goes out in the acidic bisulfite solution. 
This improved oxidation process works for other difficult to oxidize 
N,N'-di-t-alkylsulfamides such as N,N'-di-t-amylsulfamide. Examples IX and 
X demonstrate the reduction in reaction time required to oxidize 
N,N'-di-t-amylsulfamide as the reaction temperature is increased and the 
solvent distilled off. 
Di-t-octyldiazene is a useful free radical generator which has been used to 
cure a polyester resin to a hard Barcol at 250.degree. F. The process 
described in this invention is applicable to other difficult to oxidize 
N,N'-di-t-alkylsulfamides such as N,N'-di-t-heptylsulfamide, 
N,N'-di-t-amylsulfamide, N,N'-di-(1-methylcyclopentyl)sulfamide, and 
N,N'-di-t-hexylsulfamide (J. W. Timberlake, M. L. Hodges and K. Betterton, 
Synthesis 1972, p.632-34; European Pat. No. 0,006,972; A. Ohno, N. Kito 
and Y. Ohnishi, Bull. Chem. Soc. Japan, 1971, 44, p.470-474).

EXAMPLES 
The following examples will demonstrate the effect of reaction temperature 
and solvent concentrations on the rate of oxidation of 
N,N'-di-t-octylsulfamide with sodium hypochlorite and caustic. The 
conversion of sulfamide to di-t-octyldiazene was followed by gas 
chromatography. The solvent peaks were not integrated in the scans. The % 
conversion was estimated by using the area % integration of the azo peak. 
The sulfamide formed some intermediate peaks which converted to azo upon 
further reaction. There were also small amounts of impurties generated 
during the course of the reactions. These were removed in most cases with 
an aqueous sodium bisulfite wash. Therefore, the difference between the % 
azo in the scan and 100% was not necessarily the % sulfamide unreacted. 
Nevertheless, the disappearance of the sulfamide peak and the intermediate 
peaks was easily monitored on a 18 inch.times.1/8 inch 3% OV-17 column. 
Normally the temperature was programmed from 80.degree. C. to 200.degree. 
C. at 8.degree. or .+-.16.degree. C./min. The compounds were very easy to 
separate under a variety of gas chromatograph conditions. A Hewlett 
Packard 5710 A gas chromatograph coupled to a 3380S integrator was used 
for the monitoring. 
Final assays were determined accurately by gas chromatography using 
analytically pure standards and internal standards. It should be noted 
that the area % assays in the Examples are not correct assays (see 
Examples II, III, IV); they are used to monitor the course of reaction. 
EXAMPLE I 
This example demonstrates the increased oxidation rate obtained at 
65.degree. C. It also indicates the inability to obtain high assay 
material when the hexane solvent is not removed during the oxidation. 
N,N'-di-t-octylsulfamide (10.1 grams, 0.0315 m) was dissolved in 30 ml of 
warm hexane in 250 ml 3 neck flask equipped with a magnetic stirrer, 
thermometer, and reflux condenser. A solution of 5.0 grams (0.063 m) of 
50% aqueous NaOH in 70 grams (0.9 m) of 10% aqueous NaClO was added 
followed by 0.5 grams of Adogen 464 phase transfer catalyst. The reaction 
was stirred vigorously and warmed to 40.degree. over 15 minutes and 
stirred 1 hour at 40.degree.-48.degree. C. VPC analysis indicated no azo 
had formed. The reaction was then warmed to 65.degree. C. over 1/2 hour. 
Only 1.5% of azo was formed. After 1/2 hour at 65.degree. C. there was 11% 
of azo formed. After 11/4 hours at 65.degree. C. there was 40% azo, after 
21/4 hours 63%, after 31/2 hours 91%, and after 51/2 hours 93% azo by area 
%. The hexane solution was separated and the crude azo worked up and 
isolated. The crude product weighed 7.6 grams and assayed 93% by area %. 
However, upon accurate analysis using an internal standard, it only 
assayed 72.9%. Obviously, it contained some high boilers that didn't show 
up on the VPC scan. 
The reaction was repeated with almost identical results. The reaction was 
complete after 4 hours but the corrected assay was only 80%. 
For the sake of comparison the following experiment was run to demonstrate 
the ineffective oxidation of N,N'-di-t-octylsulfamide in hexane at 
temperatures below 60.degree. C. in the presence of a phase transfer 
catalyst. 
N,N'-di-t-octylsulfamide (28.3 grams, 0.088 m) was dissolved in 50 ml of 
hexane in a 500 ml round bottom flask equipped with a magnetic stirrer, 
thermometer and reflux condenser. A solution of 16 grams (0.2 m) of 50% 
NaOH in 150 grams (0.2 m) of 10% NaClO was added followed by 0.5 grams of 
Adogen 464 phase transfer catalyst. The reaction was stirred vigorously 
for 15 minutes without any apparent reaction. The reaction was warmed to 
45.degree. C. on a warm water bath over 15 minutes and then stirred 2 
hours at 40.degree.-45.degree. C. A gas chromotographic scan after the 
first hour indicated that there was about 6% of azo present. The reaction 
was stirred overnight without any external heating. After stirring 
overnight, the % azo increased to 8%. The reaction was warmed back up to 
50.degree. C. for an additional 81/4 hours. After 4 hours at 45.degree. 
-50.degree. C. the azo peak increased to 30% and by the end of the day it 
had increased to 64%. The reaction was allowed to stir overnight for a 
second night at room temperature. By the next morning the azo peak had 
increased to 71%. The reaction mixture was transferred to a separatory 
funnel and the bleach layer separated. The hexane solution was washed with 
water and saturated NaHCO.sub.3 solution, dried over anhydrous Na.sub.2 
SO.sub.4, filtered, and heated on a rotating evaporator under reduced 
pressure to strip off the hexane. The residue was a yellow-green liquid 
which weighed 24.1 grams but only assayed 70% by area %. 
EXAMPLE II 
This example demonstrates that the phase transfer catalyst in Example I was 
not necessary to obtain a fast reaction rate. 
The reaction of Example I was repeated except that the Adogen 464 was not 
used. VPC analysis indicated the reaction was complete after reacting 31/2 
hours at 65.degree. C. The crude product was worked up and isolated in the 
same manner as before. The crude product assayed 93.2% by area % but only 
78.3% by internal standard. The results were very similar to those 
obtained in Example I with a phase transfer catalyst. 
EXAMPLE III 
This example demonstrates how the N,N'-di-t-octylsulfamide is prepared in 
hexane and then oxidized without isolating the sulfamide. The reaction was 
run without a phase transfer catalyst. 
Into a 1000 ml 3-neck round bottom flask were added 84.0 grams (0.62 m) of 
95% t-octylamine and 200 ml of hexane. The flask was equipped with a 
mechanical stirrer, thermometer, and 25 ml pressure equalizing dropping 
funnel and was placed in a dry ice-isopropanol bath. The solution was 
cooled to -20.degree. C. and then 20.9 grams (0.15 m) of 97% sulfuryl 
chloride, diluted to 25 ml with hexane, was added dropwise over 20 minutes 
from a dropping funnel while holding the reaction temperature below 
0.degree. C. After the addition was completed, the isopropanol bath was 
removed and the reaction allowed to warm to 10.degree. C. over 10 minutes. 
A warm water bath was used to raise the temperature to 45.degree. C. The 
material caked in the necks of the flask was rinsed down with about 50 ml 
of hexane and the reaction was stirred 20 minutes at 40.degree.-50.degree. 
C. Then 100 ml of warm water was added. All the solids dissolved. The 
reaction mixture was transferred to a separatory funnel and the aqueous 
layer was separated and saved for t-octylamine recovery. The hexane 
solution was washed with 50 ml 10% HCl to remove any excess t-octylamine 
and the acid layer added to the aqueous layer. 
The hexane solution of the N,N'-di-t-octylsulfamide was transferred to a 1 
liter 3-neck round bottom flask and a solution of 30 grams (0.38 m) of 50% 
NaOH in 300 grams of 10% NaClO was added. The flask was equipped with a 
magnetic stirrer, thermometer, and reflux condenser. The flask was lowered 
into a pre-heated 80.degree. C. oil bath and the contents were stirred 
vigorously. The reaction was monitored by gas chormatography. It took 
approximately 1/2 hour for the contents to reach a gentle reflux. During 
the course of the reaction, the temperature rose to 68.degree. C. and 
there was considerable foaming in the flask. The bath had to be lowered 
and the reaction mass was cooled below 65.degree. C. so that the foaming 
would subside. The reaction started out very slowly and required 51/2 
hours of gentle refluxing before the oxidation was completed. The reaction 
mass was cooled to 30.degree. C. and transferred to a separatory funnel. 
The bleach layer was separated. The hexane solution was washed twice with 
water, and once with a 15% NaHSO.sub.3 solution, water, and saturated 
NaHCO.sub.3 solution. The hexane solution was dried over anhyrous sodium 
sulfate, filtered, and heated on a rotating evaporator under reduced 
pressure to strip off the hexane. The residue weighed 33.9 grams and 
assayed 88.5% by area %. It assayed 77.6% by internal standard. The 
correct yield was 26.3 grams (69% overall yield). 
EXAMPLE IV 
This example is a repeat of Example III except that a phase transfer 
catalyst was used in the oxidation to eliminate the foaming; after 31/4 
hours, the reflux condenser was replaced with a distilling head and most 
of the hexane was distilled off from the reaction mixture. 
The N,N'-di-t-octylsulfamide was prepared in the same manner as in Example 
IV except that only 150 ml of hexane were used in the reaction and the 
reaction temperature was held below 15.degree. C. instead of 0.degree. C. 
The hexane solution of the sulfamide was oxidized with a solution of 30 
grams of 50% NaOH in 300 grams of 11% NaClO using 0.2 grams of Adogen 464. 
The reaction was refluxed for 31/4 hours in the same nammer as in Example 
III. There was no foaming present. At this point the gas chromatograph 
indicated only 22% conversion to azo. Therefore, the reflux condenser was 
replaced by a distilling head connected to a downward condenser and the 
hexane was allowed to distill off. After 2 hours of additional stirring, 
the bleaching power of the aqueous layer was rather weak so an additional 
80 grams of 9% NaClO were added and the reaction mass was stirred an 
additional hour. The reaction was cooled to 30.degree. C. and worked up as 
in Example III. After stripping, the residue weighed 30.7 grams and 
assayed 92.2% by the internal standard method. The corrected yield was 
28.3 grams (74.2% yield). 
EXAMPLE V 
This example is essentially a repeat of Example IV except that the 
distilling head was put on the flask at the beginning of the oxidation and 
the hexane began to distill off as soon as the reaction got warm enough. 
The N,N'-di-octylsulfamide was prepared in the same manner as in Example IV 
except 200 ml of hexane and 89.9 grams (10% excess) of 95% t-octylamine 
were used. 
The hexane solution of the sulfamide was oxidized with a solution of 30 
grams of 50% NaOH in 300 grams of 13.9% bleach using 0.5 grams of Adogen 
464 and 5 grams of t-butyl alcohol. The reaction flask was lowered into an 
80.degree. C. oil bath and the reaction mass was stirred vigorously for 2 
hours while distilling off the hexane. It took about 1/2 hour before most 
of it had distilled off. Very little reaction occurred in the first 1/2 
hour. The oxidation was about 85% complete at the end of 1 hour and 
essentially complete (by VPC analysis) at the end of 11/2 hours. The 
reaction was stirred an additional 1/2 hour to insure complete oxidation 
but there was no change in the VPC scan. The reaction was cooled to 
30.degree. C. and worked up as in Example III. After high vacuum 
stripping, the residue weighed 32.4 grams and assayed 96.8% by internal 
standard. The correct yield was 31.4 grams (82.4% yield). 
The reaction was repeated two more times using only 5% excess t-octylamine. 
The crude product assayed 95.6% and 95.9% and the corrected yields were 
81.8% and 83% respectively. 
EXAMPLE VI 
This Example is essentially a repeat of Example V. The reaction was 
monitored by gas chromatography and the extent of reaction compared versus 
the amount of hexane distilled off. A phase transfer catalyst was not used 
in the oxidation step. 
The N,N'-di-t-octylsulfamide was prepared in the same manner as in Example 
V except 200 ml of hexane were used. 
The hexane solution of the sulfamide was oxidized with a solution of 30 
grams of 50% NaOH in 225 grams of 13.9% bleach using 5 grams of t-butyl 
alcohol. The reaction flask was lowered into an 80.degree. C. oil bath and 
the reaction mass was stirred vigorously. As the reaction mass heated up, 
the hexane began to distill off and was collected in a graduate and was 
measured at 15 minute intervals. At the same time, the reaction mass was 
sampled and injected into the gas chromatograph. A 0.25 minute delay was 
applied to the integrator so that the solvent peak would not integrate. 
The % azo formed was qualitatively determined by integrating the rest of 
the scan. The results are summarized in Table I. As the reaction 
progressed (about 50 minutes), the reaction mixture began to foam 
excessively; temperature of the oil bath had to be lowered and the 
stirring was stopped periodically to prevent the reaction mixture from 
foaming out of the flask. After 90 minutes, the reaction was essentially 
completed and the foaming had died out. The reaction mass was stirred an 
additional 45 minutes to insure completion of reaction. The reaction was 
cooled to 30.degree. C. and worked up as in Example III. After high vacuum 
stripping, the residue weighed 31.9 grams and assayed 94.3% by internal 
standard. The corrected yield was 30.1 grams (79.0%). 
TABLE I 
______________________________________ 
Reaction 
Time Bath Temp. 
Reaction % Azo Formed 
ml Hexane 
(minutes) 
.degree.C. 
Temp. .degree.C. 
(Area %) Collected 
______________________________________ 
0 78 25 -- -- 
30 77 61 0 25 
45 79 64 28.1 105 
60 77 73 64.4 155 
75 74 75 92.2 170 
90 71 67 97.2 175 
105 76 65 98.5 175 
120 78 68 99.0 175 
135* 78 68 99.5 175 
______________________________________ 
*Removing the delay on the integrator and reinjecting a sample of the 
organic layer at the end of the reaction indicated it still contained 
about 39% hexane despite the fact distillation had ceased. 
EXAMPLE VII 
This Example is a repeat of Example VI except that there wasn't any t-butyl 
alcohol present in the oxidation. The reaction was monitored by gas 
chromatography and the extent of reaction was compared with the amount of 
hexane distilled in Table II. Foaming problems were encountered during the 
oxidation due to the lack of a phase transfer catalyst. After high vacuum 
stripping, the residue weighed 31.9 grams and assayed 94.3% by internal 
standard. The corrected yield was 30.1 grams (79.0%). 
TABLE II 
______________________________________ 
Reaction 
Time Bath Temp. 
Reaction % Azo Formed 
ml Hexane 
(minutes) 
.degree.C. 
Temp. .degree.C. 
(Area %) Collected 
______________________________________ 
0 70 25 -- -- 
30 78 62 0 10 
45 78 63 0.8 35 
60 78 63 3.9 65 
90 78 73 48.1 160 
105 80 85 94.8 188 
120 82 76 98.0 190 
135 81 71 98.1 190 
150 80 69 98.1 190 
______________________________________ 
EXAMPLE VIII 
Curing an Unsaturated Polyester-Styrene Resin 
With Di-t-Octyldiazene 
An unsaturated polyester resin was prepared by reacting maleic anhydride 
(1.0 mole), phthalic anhydride (1.0 mole), and propylene glycol (2.2 
moles) until an acid number of 45-50 was obtained. To this was added 
hydroquinone at a 0.013% concentration. Seven parts of this unsaturated 
polyester was diluted with 3 parts of monomeric styrene to obtain a 
homogeneous blend having a viscosity of 13.08 poise and a specific gravity 
of 1.14. 
To 20 grams of this blend was added 0.28 gram of crude di-t-octyldiazene; 
the mixture was stirred well with a wooden spatula. The sample was poured 
into a test tube and placed in a 121.degree. C. oil bath. The internal 
temperature was recorded as a function of time and a peak exotherm of 
229.degree. C. was reached in 5.0 minutes indicating that an excellent 
cure of the unsaturated polyester-styrene resin blend had occurred. 
Without an initiator, no cure of the resin blend had occurred even after 30 
minutes. 
EXAMPLE IX 
This Example demonstrates the oxidation of N,N'-di-t-amylsulfamide at 
65.degree. C. in the presence of a phase transfer catalyst. 
N,N'-di-t-amylsulfamide (9.5 grams, 0.04 m) was slurried in 40 ml of hexane 
in a 3 neck 500 ml round bottom flask equipped with a magnetic stirrer, 
thermometer, and reflux condenser. A solution of 10 grams of 50% NaOH in 
150 grams of 13.9% bleach was added. The flask was lowered into a 
preheated oil bath (73.degree. C.) and was stirred vigorously. The extent 
of reaction was followed by gas chromatography. The gas chromatographic 
scans were a qualitative indication of how long the reaction had to be 
refluxed to complete the oxidation. The scans indicated that the reaction 
was completed after refluxing for 5 hours at 64.degree.-65.degree. C. The 
reaction was refluxed an additional 1/2 hour to insure complete reaction. 
The reaction mixture was cooled to room temperature and was transferred to 
a separatory funnel. The bleach layer was separated from the hexane 
solution layer; the hexane layer was washed with 50 ml portions of water, 
15% NaHSO.sub.3 solution, and saturated NaHCO.sub.3 solution and was 
dried over anhydrous Na.sub.2 SO.sub.4. The hexane solution layer was 
filtered and the hexane was stripped off on a rotating evaporator under 
reduced pressure at 10.degree. C. The crude product weighed 5.1 grams and 
assayed 93.3% by area % on the gas chromatograph. The crude % yield was 
69.6%. The reaction required 5 hours to run. 
This is a comparative experiment which demonstrates the ineffective 
oxidation of N,N'-di-t-amylsulfamide in pentane at 30.degree.-40.degree. 
C. in the presence of a phase transfer catalyst and t-butanol. The 
N,N'-di-t-amylsulfamide was prepared from t-amylamine and sulfuryl 
chloride in hexane. 
N,N'-di-t-amylsulfamide (9.4 grams, 0.04 m) was slurried in 40 ml of 
pentane in a 3 neck 500 ml round bottom flask equipped with a magnetic 
stirrer, thermometer, and reflux condenser. A solution of 10 grams of 50% 
NaOH in 150 grams of 13.9% NaClO was added followed by 4 grams of 
t-butanol. The reaction was stirred for 21/4 hours at 25.degree. C. A gas 
chromatographic scan indicated essentially no reaction had occurred. Then 
0.5 gram of Adogen 464 phase transfer catalyst was added and the reaction 
mass was stirred 21/2 hours at 30.degree. C. By this point all the 
sulfamide had dissolved and a gas chromatographic scan indicated that 
about 30% conversion to di-t-amyldiazene had occurred. The reaction was 
warmed to 36.degree. C. and refluxed gently for an additional 31/4 hours. 
Gas chromatographic analysis indicated about 65% conversion to 
di-t-amyldiazene. The reaction was stirred overnight at room temperature 
and the conversion increased to about 85%. The reaction was warmed to 
40.degree. C. and stirred until gas chromatographic analysis indicated 
that the oxidation was completed. This required an additional six hours. 
The reaction mixture was cooled to room temperature and transferred to a 
separating funnel. The bleach layer was separated from the pentane 
solution layer; the pentane layer was then washed with 50 ml portions of 
water, 15% NaHSO.sub.3 solution, and saturated NaHCO.sub.3 solution, dried 
over anydrous Na.sub.2 SO.sub.4, filtered, and heated on a rotating 
evaporator under reduced pressure at 0.degree. C. to strip off the 
pentane. The residue was a yellow-green liquid which weighed 5.9 grams and 
assayed 97.1% by area % on the gas chromatograph. The crude % yield was 
83.7%. 
This reaction took a total of 291/2 hours to go to completion. During the 
first two hours, the reaction mass did not have a phase transfer catalyst 
therein and only about 9 hours of the 291/2 hours were at reflux. 
Nevertheless, the reaction ran quite slow even at 35.degree.-40.degree. C. 
EXAMPLE X 
This Example is a repeat of Example IX except that most of the hexane was 
distilled off during the course of the reaction. 
N,N'-di-t-amylsulfamide (9.5 grams, 0.04 m) was weighed into a 3 neck 500 
ml round bottom flask equipped with a magnetic stirrer, thermometer, and 
distilling head connected to a condenser and receiver. To the flask was 
added 40 ml of hexane, 0.5 grams of Adogen 464 phase transfer catalyst, 
and a solution of 10 grams of 50% NaOH in 150 grams of 13.9% NaClO. The 
flask was stoppered and lowered into a preheated oil bath (80.degree. C.) 
and the reaction mass was stirred vigorously. The reaction was monitored 
at 1/2 hour intervals by gas chromatography. The gas chromatographic scans 
indicated that the reaction was completed in less than two hours. Little 
reaction occurred during the first 1/2 hour as the reaction mass warmed up 
to 65.degree. C. and the hexane began to distill over. The conversion to 
di-t-amyldiazene was only about 15%. During the second half hour most of 
the hexane distilled over and the conversion increased to 52% as the 
reaction temperature increased to 75.degree. C. The conversion increased 
to 95% over the third half hour and was completed by the time the two hour 
scan was run. The reaction was cooled back to room temperature and the 
hexane that was distilled off was added back to the reaction mixture. The 
bleach layer was separated from the hexane solution layer; then the hexane 
layer was washed with several 50 ml portions of water, 15% NaHSO.sub.3 
solution, saturated NaHCO.sub.3 solution, and was dried over anhydrous 
Na.sub.2 SO.sub.4. The solution was filtered and the hexane was stripped 
off on a rotating evaporator under reduced pressure at 10.degree. C. The 
crude product weighed 5.4 grams and assayed 94.3% by area % on the gas 
chromatograph. The crude % yield was 74.5%.