Process for the preparation of N,N-disubstituted mono- and oligourethanes

N,N-disubstituted monourethanes and oligourethanes are produced by reacting (a) N-aliphatically and/or N-cycloaliphatically and/or N-araliphatically substituted monourethanes and/or oligourethanes with an alkylating agent in the presence of a solid alkali metal hydroxide. No solvent need by employed but if a solvent is used, that solvent should be an aprotic organic solvent. The alkali metal hydroxide must be used in an equivalent amount. A phase transfer catalyst may optionally be employed. The N,N-disubstituted urethanes obtained by this process are useful in the production of dyes, pharmaceutical products and thermostable synthetic materials.

BACKGROUND OF THE INVENTION 
This invention relates to a process for the preparation of 
N,N-disubstituted mono and oligourethanes. 
It is known that monourethanes can be reacted with lower alkyl halides and 
alkyl sulphates to form N,N-disubstituted monourethanes (See U. Petersen 
in Houben-Weyl, Volume E 4, published by Hagemann). However, the known 
processes have the disadvantage that good results can be obtained only if 
special, relatively expensive bases such as metal hydrides (e.g., NaH) are 
used. Furthermore, since the side reaction of olefin formation 
predominates under these reaction conditions when secondary alkylating 
agents are used, these processes are restricted to primary alkylating 
agents. 
It is also known that N-aryl substituted monourethanes may be N-alkylated 
under the conditions of phase transfer catalysis. Although secondary 
alkylating agents may be used in this process, the method completely fails 
with N-aliphatically substituted urethanes (See S. Julia, A. Ginebreda, 
Anales de Quimica (Madrid), Volume 75, page 348, lines 7 to 13). In the 
examples described in the Anales de Quimica publication, the solvent used 
is either methylene chloride or dimethyl sulphoxide or methyl ethyl 
ketone. Triethyl benzyl ammonium chloride is used in all cases as a phase 
transfer catalyst. These solvents have disadvantages which in some cases 
considerably reduce the reaction yields. For example, methylene chloride 
itself acts as an alkylating agent under these reaction conditions while 
methyl ethyl ketone forms aldol type by-products by auto condensation. 
Dimethyl sulphoxide forms toxic, malodourous by-products and is difficult 
to remove from the reaction products. 
Furthermore, in many cases the phase transfer catalysts required for the 
reactions make it difficult to work up the reaction mixtures due to the 
formation of emulsions. A great effort is required to remove them 
completely from the reaction products. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide an economical process 
for alkylating N-mono substituted urethanes which would avoid the 
disadvantages described above. It has now surprisingly been found that the 
desired N,N-disubstituted mono and oligourethanes are obtained when 
N-aliphatically, N-cycloaliphatically or N-araliphatically substituted 
mono and oligourethanes are reacted with alkylating agents in the presence 
of an at least equivalent quantity of a solid metal hydroxide, either 
without solvents or in an aprotic organic solvent. A phase transfer 
catalyst may optionally be present.

DETAILED DESCRIPTION OF THE INVENTION 
The present invention relates to a process for alkylating N-aliphatically 
monosubstituted urethanes. In this process, N,N-disubstituted mono- and 
oligourethanes corresponding to the general formula(e) 
##STR1## 
in which n is an integer from 1 to 6, preferably from 1 to 4, 
n.sub.1 is an integer from 1 to 6, preferably from 1 to 3, 
R.sub.1 represents an aromatic hydrocarbon group having 6 to 18 (preferably 
6 to 13) carbon atoms, an aliphatic hydrocarbon group having 1 to 18 
(preferably 1 to 6) carbon atoms, a cycloaliphatic hydrocarbon group 
having 4 to 30 (preferably 6 to 15) carbon atoms or an araliphatic 
hydrocarbon group having 7 to 30 (preferably 7 to 15) carbon atoms, 
R.sup.2 represents an aliphatic hydrocarbon group having 1-18 (preferably 
2-8) carbon atoms, a cycloaliphatic hydrocarbon group having 4-30 
(preferably 6-15) carbon atoms or an araliphatic hydrocarbon group having 
7-20 (preferably 7-13) carbon atoms, 
R.sup.3 represents an aromatic hydrocarbon group having 6-18 (preferably 
6-13) carbon atoms, an aliphatic hydrocarbon group having 1-18 (preferably 
1-12) carbon atoms, a cycloaliphatic hydrocarbon group having 7-30 
(preferably 7-15) carbon atoms or an araliphatic hydrocarbon group having 
7-30 (preferably 7-15) carbon atoms, 
are prepared in high yields by reacting urethanes corresponding to the 
formula(e) 
##STR2## 
in which n, n.sub.1 R.sup.1 and R.sup.2 have the meanings indicated above 
with alkylating agents in the presence of at least equivalent quantities 
of a solid metal hydroxide, either solvent free or in an aprotic organic 
solvent and optionally in the presence of a phase transfer catalyst. 
To obtain high yields, it is particularly advantageous to dissolve the 
urethane used as starting material, the alkylating agent and any phase 
transfer catalyst, in an aprotic organic solvent (preferably 
chlorobenzene, dimethylformamide or N-methyl pyrrolidone) or in an excess 
of alkylating agent, and then to add the metal hydroxide (preferably 
sodium or potassium hydroxide) in a solid form, either portionwise or 
continuously, at low reaction temperatures (e.g., 20.degree. to 30.degree. 
C.) optionally with cooling, and then to stir, optionally with heating to 
50.degree.-80.degree. C., until the reaction has been completed. If polar 
aprotic solvents such as dimethylformamide, N-methyl pyrrolidone or 
dimethyl sulphoxide are used, the addition of a phase transfer catalyst 
may be omitted without incurring any disadvantages and working up of the 
reaction mixture is thereby considerably simplified. 
Compared with the known processes, the process of the present invention 
surprisingly provides N,N-di-substituted urethanes by a simpler and more 
economical procedure and with higher yields, higher volume/time yields and 
greater purity, especially on a technical scale. 
In contrast to the expensive and dangerous metal hydrides used in the known 
processes, the metal hydroxides used in the present process are less 
expensive, quite safe and easier to handle. 
It must be considered particularly surprising that in contrast to what is 
stated in the literature, N-aliphatically substituted urethanes can also 
be alkylated by the process of the present invention. 
The urethane used as starting material for the process of the present 
invention may be prepared, for example, by the reaction of aliphatic mono- 
or oligoisocyanates with mono- or di- to hexahydric alcohols by known 
methods, either solvent free or in solution, optionally in the presence of 
a catalyst. 
These urethanes may also be prepared, for example, by the condensation of 
primary mono- or oligo-amines with chloroformic acid esters of mono- or 
di- to hexahydric alcohols. They may, of course, also be prepared by the 
reaction of carbamic acid chlorides with alcohols. 
Alcohols which may be used for the preparation of the urethanes used as 
starting materials in the process of the present invention include 
alcohols of the formula 
EQU R.sup.1 (OH).sub.n 
in which 
n represents an integer from 1 to 6 (preferably 1 to 4), and 
R.sup.1 represents an aromatic hydrocarbon group having 6 to 18 (preferably 
6 to 13) carbon atoms, an aliphatic hydrocarbon group having 1 to 18 
(preferably 1 to 6) carbon atoms, a cycloaliphatic hydrocarbon group 
having 4 to 30 (preferably 6 to 15) carbon atoms or an araliphatic 
hydrocarbon group having 7 to 30 (preferably 7 to 15) carbon atoms. 
Such alcohols include monohydric alcohols of the kind described in Ullmanns 
Enzyklopadie der Technischen Chemie, Volume 7, pages 205-206, 4th Edition, 
1974, as well as phenols and substituted phenols. 
Examples of suitable polyhydric alcohols are: ethylene glycol, (1,2)- and 
(1,3)-propylene glycol, (1,4)- and (2,3)-butylene glycol, (1,6)-hexane 
diol, (1,8)-octanediol, neopentyl glycol, 1,4-bis-hydroxy methyl 
cyclohexane, 2-methyl-1,3-propanediol, glycerol, trimethylol propane, 
(1,2,6)-hexanetriol, (1,2,4)-butanetriol, trimethylol ethane, 
pentaerythritol, quinitol, mannitol, sorbitol, formitol, methylglycoside 
and/or 1,4-, 3,6-dianhydrohexitols as well as polyvalent phenols such as 
pyrocatechol, resorcinol, hydroquinone and polynuclear phenols, such as 
bisphenol A. Mixtures of these alcohols may, of course, also be used. 
Isocyanates which may be used for the preparation of the urethanes used as 
starting materials correspond to the general formula 
EQU R.sup.2 (NCO).sub.n.sbsb.1 
in which 
n.sub.1 represents an integer from 1-6 (preferably 1-3), and 
R.sup.2 represents an aliphatic hydrocarbon group having 1-18 (preferably 
2-8) carbon atoms, a cycloaliphatic hydrocarbon group having 4-30 
(preferably 6-15) carbon atoms or an araliphatic hydrocarbon group having 
7-20 (preferably 7-13) carbon atoms. 
Specific examples of such isocyanates include: isocyanato-methane, -ethane, 
-propane, -butane, -pentane, and -hexane; 6-chlorohexyl isocyanate; 
isocyanatocyclohexane; benzyl isocyanate; tetramethylene diisocyanate; 
hexamethylene diisocyanate; decamethylene diisocyanate; 
1,3-di-(3-isocyanatopropoxy)-2,2-dimethyl propane; (1,4)-cyclohexane 
diisocyanate, (2,4)-methyl cyclohexane diisocyanate, methyl cyclohexane 
(2,6)-diisocyanate; 1,3-diisocyanatocyclohexane; mixtures of (2,4)-methyl 
cyclohexane diisocyanate and (2,6)-methyl cyclohexane diisocyanate; 
dicyclohexyl methane-4,4'-diisocyanate; 
1-isocyanato-3-isocyanato-methyl-3,5,5-trimethyl-cyclohexane (isophorone 
diisocyanate); 1,2-di-(iso- cyanato-methyl)-cyclobutane; m- and p-xylylene 
diisocyanate; .alpha.,.alpha.,.alpha.',.alpha.'-tetramethyl-m- and/or 
p-xylylene diisocyanate and hexahydroxylylene diisocyanate. In the case of 
cycloaliphatic diisocyanates, any stereoisomers or mixtures of these 
compounds may be used. 
Mixtures of the above-mentioned isocyanates may, of course, also be used. 
The alkylating agents used in the process of the present invention include 
those corresponding to the formula 
EQU R.sup.3 X 
in which 
R.sup.3 represents an aromatic hydrocarbon group having 6-18 (preferably 
6-13) carbon atoms, an aliphatic hydrocarbon group having 1-18 (preferably 
1-12) carbon atoms, a cycloaliphatic hydrocarbon group having 7-30 
(preferably 7-15) carbon atoms or an araliphatic hydrocarbon group having 
7-30 (preferably 7-15) carbon atoms, and 
X represents a suitable removable substituent such as halogen atom or a 
sulfate, sulfonate, phosphate or phosphonate group. 
The hydrocarbon R.sup.3 may, of course, carry other functional groups in 
addition to the group X, provided they are inert under the reaction 
conditions or react in a well defined manner with the reactants according 
to the invention. Examples of such functional groups include: nitro 
groups, certain ester, urethane, amide and sulfonyl groups, unactivated, 
aromatically bound halogen, epoxide groups, aziridine groups, ether groups 
and thioether groups. 
Specific examples of suitable alkylating agents include: methylchloride and 
bromide, ethylchloride and bromide, propylchloride and bromide, 
i-propylchloride and bromide, n-butylchloride and bromide, 
isobutylchloride and bromide, cyclohexylchloride and bromide, octyl, 
nonyl, decyl, undecyl and dodecyl chloride and bromide, benzyl chloride 
and bromide, allylchloride and bromide, p-nitro benzylchloride and 
bromide, 2,4-dinitrochlorobenzene, 2,4-dinitrofluorobenzene, 
2,4,6-dinitrochlorobenzene, 2,4,6-dinitrofluorobenzene, dimethylsulfate, 
diethyl sulfate, the methyl ester and ethyl ester of p-toluene sulfonic 
acid, ethylene chlorohydrin, ethylene bromo- hydrin and epichlorohydrin. 
Mixtures of these alkylating agents may, of course, also be used. 
The following are particularly preferred alkylating agents: methyl chloride 
and bromide, ethyl chloride and bromide, dodecyl chloride and bromide, 
allylchloride and bromide, benzyl chloride and p-tosyl ester. 
When readily volatile alkylating agents such as methylene chloride or 
bromide or ethyl chloride are used, the reaction is preferably carried out 
in an autoclave under pressure. 
The reaction of urethane with alkylating agent may be carried out either in 
an aprotic organic solvent or in excess, liquified alkylating agent, 
optionally in the presence of a phase transfer catalyst. 
The bases used in the process of the present invention are solid, 
preferably finely powdered metal hydroxides such as alkali metal 
hydroxides (e.g., potassium or sodium hydroxide). Sodium hydroxide is 
preferred on economic grounds. The hydroxide of lithium, rubidium or 
barium, for example, or moist silver oxide may, of course, also be used. 
It may in some cases be advantageous to use mixtures of these metal 
hydroxides. 
The metal hydroxides are used in equivalent quantities based on the amount 
of urethane groups. The above described urethanes used as starting 
materials may be reacted with the alkylating agent in stoichiometric 
quantities, less than stoichiometric quantities or in excess (based on the 
number of urethane groups present in the molecule). It is preferred to use 
0.3-5 mol, particularly 1-2 mol of alkylating agent for each mol of 
urethane groups. Only partial alkylation is, of course, obtained when a 
subequivalent quantity of alkylating agent is used but the use of a 
substantial excess of alkylating agent is uneconomical. 
The process of the present invention is generally carried out at a 
temperature of 0.degree.-180.degree. C., preferably 10.degree.-80.degree. 
C. and most preferably at room temperature, under excess pressure or 
reduced pressure or, preferably without application of pressure, and 
either continuously or batch-wise. 
The dwell time may be, for example, 0.5 to 24 hours and is preferably in 
the region of 0.5 to 10 hours. 
The reaction may be carried out in excess alkylating agent, or preferably, 
in an aprotic organic solvent. 
Aprotic organic solvents which are inert under the reaction conditions 
according to the invention may be used. Examples of such solvents are 
those described in Ullmanns Enzyklopadie der Technischen Chemie Volume 14, 
4th Edition, Verlag Chemie 1978, page 305. Specific examples of suitable 
solvents include: benzene, toluene, xylene, ethylbenzyl, cumene, methylene 
chloride, chloroform, dichlorobenzene, trichlorobenzene, nitrobenzene, 
acetone, methylethyl ketone, diethyl ketone, cyclohexanone, diethyl ether, 
diisopropyl ether, tetrahydrofuran, dioxane, dimethylformamide, dimethyl 
acetamide, dimethyl sulfoxide, tetramethylene sulfone, furfurol. 
nitromethane, nitroethane, nitropropane, N-methyl pyrrolidone and 
hexamethylene phosphonic acid triamide. Chlorobenzene, dimethylformamide, 
N-methyl pyrrolidone and tetramethylene sulfone are preferred. 
Mixtures of these solvents may, of course, also be used. 
It may in some cases be advantageous to carry out the reaction in the 
presence of a phase transfer catalyst. Catalysts of this kind are 
described, for example, by E. V. and S. S. Dehmlow in Phase Transfer 
Catalysis, 2nd Edition, Verlag Chemie 1983. Quaternary ammonium and 
phosphonium salts corresponding to the formula: 
##STR3## 
are suitable catalysts. In the above formula, Z represents nitrogen or 
phosphorus and R', R",R"' and R"", which may be identical or different, 
each represents an alkyl group with 1-18 carbon atoms although one of the 
groups may be an araliphatic group containing 7-15 carbon atoms, and the 
sum of carbon atoms of the four groups is preferably 12 to 29 and 
A.sup.(-) represents an halogenide or phosphonate. 
The following are typical examples of suitable catalysts: 
N-benzyl-N,N,N-triethyl-ammonium chloride or bromide, 
N-benzyl-N-dodecyl-N,N-dimethyl-ammonium chloride or bromide, 
N,N,N,N-tetra-n-hexyl-ammonium chloride or bromide, 
N-benzyl-N,N,N-tri-n-octyl-ammonium chloride or bromide and phosphonium 
salts corresponding to these ammonium salts. 
The quaternary ammonium and phosphonium salts mentioned as examples are 
preferably put into the process of the present invention in a solvent free 
form or as aqueous solutions (for example, with a solids content of 30 to 
60 wt. %) and preferably in a quantity of 1-10 mol %, based on the molar 
number of urethane groups present. 
Phase transfer catalysts may be omitted without any deleterious effect if 
polar aprotic solvents such as dimethylformamide, N-methyl-pyrrolidone, 
dimethyl sulfoxide or sulfolan are used. 
The process according to the invention may be carried out, for example, by 
introducing the urethane, alkylating agent and optional catalyst into the 
selected solvent and the solid, finely ground metal hydroxide may then be 
added either portion-wise or continuously with stirring and optionally 
cooling. The reaction mixture may then be stirred at room temperature or 
optionally at elevated temperature until thin layer chromotographic or gas 
chromatographic analysis shows complete conversion. 
The product may be worked up by known methods. When water-miscible solvents 
are used and the reaction products are solid and insoluble in water, the 
reaction mixture may be stirred into water and the precipitated reaction 
product may then be isolated by suction filtration in the usual manner. If 
the reaction products are oily, they are suitably worked up by one of the 
usual methods of extraction. The crude products may, if necessary, be 
purified by conventional methods such as recrystallization or 
distillation. 
The N,N-disubstituted urethanes which may be prepared by the process of the 
present invention are active ingredients and valuable starting materials 
for the preparation of dyes, pharmaceutical products and thermostable 
synthetic materials. The N,N-disubstituted urethanes produced in 
accordance with the present invention in particular show greater thermal, 
thermooxidative and photooxidative stability (see R. Vieweg, A. Hochtlen, 
Kunststoff Handbuch Volume VII, Polyurethane, Hanser Verlag, Munich 1966, 
pages 11 and 21) and better fire characteristics than the corresponding 
N-monosubstituted urethanes. 
The corresponding substituted secondary amines may be prepared by 
hydrolysis of the N,N-disubstituted urethanes. These amines are also 
important starting materials for the synthesis of active ingredients and 
the preparation of formulations for synthetic materials. 
The invention is further illustrated but is not intended to be limited by 
the following examples in which all parts and percentages are by weight 
unless otherwise specified. 
EXAMPLES 
All the reaction products were tested for purity by gas chromatography or 
thin layer chromatography and their identity was confirmed by IR and NMR 
Spectra. 
IR spectroscopy in particular provides a convenient method of checking the 
rate of conversion since the characteristic bands for N-monosubstituted 
urethanes at 3200-3500 cm.sup.-1 (N--H) and 1530-1560 cm.sup.-1 (N--H) 
disappear in the course of the reaction. 
EXAMPLE 1 
16 g of powdered sodium hydroxide were added portion-wise in the course of 
2 hours to a solution of 58.1 g of N-6-chlorohexyl-carbamic acid methyl 
ester and 51.7 g of diethyl sulfate in 300 ml of dimethyl-formamide (DMF) 
with stirring at 20.degree. C. When all the sodium hydroxide had been 
added, stirring was continued for a further 3 hours at room temperature 
and the solvent was then evaporated off under vacuum and the residue was 
taken up in 700 ml of methylene chloride. The organic phase was washed, 
first with saturated NH.sub.4 Cl solution and then with water, and 
dehydrated over Na.sub.2 SO.sub.4. After evaporation of the solvent, the 
oily crude product was fractionated in a high vacuum. 
Yield: 47.8 g (72%), b.p.: 90.degree. C./0.13 mbar. (colorless oil). 
EXAMPLE 2 
52.4 g of N-tertiary butyl-carbamic acid methyl ester, 57 g of benzyl 
chloride and 18 g of powdered sodium hydroxide were reacted in 300 ml of 
DMF in the same manner as in Example 1. 
After-stirring time: 15 hours (h) at 50.degree. C. 
Yield: 43.3 (49%), b.p.: 90.degree. C./0.13 mbar (colorless oil). 
EXAMPLE 3 
49.5 g of N-benzyl-carbamic acid methyl ester, 25.2 of allyl chloride and 
13.2 g of powdered sodium hydroxide were reacted in 300 ml of DMF in the 
same manner as in Example 1. 
After-stirring time: 15 h at 25.degree. C. 
Yield: 51.1 g (83%), b.p.: 118.degree. C./0.16 mbar (colorless oil). 
EXAMPLE 4 
49.5 of N-benzyl-carbamic acid methyl ester, 48 g of n-butyl bromide and 14 
g of powdered sodium hydroxide were reacted in 300 ml of DMF in the same 
manner as in Example 1. 
After-stirring time: 15 h at 50.degree. C. 
Yield: 50.4 g (76%), b.p.: 110.degree. C./0.2 mbar (colorless oil). 
EXAMPLE 5 
49.5 g of N-benzyl-carbamic acid methyl ester, 48 g of n-butyl bromide, 
12.1 g of methyl-tridecyl-ammonium chloride and 14 g of powdered sodium 
hydroxide were reacted in 400 ml of chlorobenzene in the same manner as in 
Example 1. 
After-stirring time: 15 h at 50.degree. C. 
Yield: 45.1 g (68%), b.p.: 110.degree. C./0.2 mbar (colorless oil). 
EXAMPLE 6 
49.5 g of N-benzyl-carbamic acid methyl ester, 61.4 g of p-toluene 
sulphonic acid methyl ester and 13.2 g of powdered sodium hydroxide were 
reacted in 300 ml of DMF in the same manner as in Example 1. 
After-stirring time: 15 h at 25.degree. C. 
Yield: 48.9 g (92%), b.p.: 96.degree. C./0.44 mbar (colorless oil). 
EXAMPLE 7 
49.5 g of N-benzyl-carbamic acid methyl ester, 49.2 g of 2-bromopropane and 
16 g of powdered sodium hydroxide were reacted in 400 ml of DMF by the 
method described in Example 1. 
After-stirring time: 15 h at 25.degree. C. 
Yield: 19.9 g (32%), b.p.: 89.degree. C./0.45 mbar (colorless oil). 
EXAMPLE 8 
49.5 g of N-benzyl-carbamic acid methyl ester, 67.5 g of dodecyl chloride 
and 24 g of powdered sodium hydroxide were reacted in 400 ml of DMF by the 
method described in Example 1. 
After-stirring time: 15 h at 50.degree. C. 
Yield: 85 g (85%) (yellowish oil). 
EXAMPLE 9 
49.5 g of N-benzyl-carbamic acid methyl ester, 30.5 g of epichlorohydrin, 
9.7 g of tetrabutyl ammonium bromide and 18.5 g of powdered potassium 
hydroxide were reacted in 400 ml of chlorobenzene by the method described 
in Example 1. 
After-stirring time: 15 h at 25.degree. C. 
Yield: 37.8 g (57%), b.p.: 135.degree. C./0.53 mbar (colorless oil). 
EXAMPLE 10 
46.4 g of diurethane (prepared from hexamethylene diisocyanate and 
methanol), 81.8 g of p-toluene sulfonic acid methyl ester and 17.6 g of 
powdered sodium hydroxide were reacted in 400 ml of N-methyl-pyrrolidone 
(NMP) by the method described in Example 1. 
After-stirring time: 15 h at 50.degree. C. 
Yield: 42.6 g (82%) (colorless oil). 
EXAMPLE 11 
46.4 g of diurethane (prepared from hexamethylene diisocyanate and 
methanol), 942 g of allyl chloride and 22 g of powdered sodium hydroxide 
were reacted in 300 ml of DMF in the same manner as in Example 1. 
After-stirring time: 15 h at 50.degree. C. 
Yield: 55.5 g (89%), b.p.: 159.degree. C./0.11 mbar (colorless oil). 
EXAMPLE 12 
57.2 g of diurethanes (prepared from isophorone diisocyanate and methanol), 
9,101.3 g of benzyl chloride and 32 g of powdered sodium hydroxide were 
reacted in 500 ml of tetramethylene sulfone (Sulfolan.RTM.) by the method 
described in Example 1. 
After-stirring time: 15 h at 60.degree. C. 
Yield: 71 g (76%) (yellowish oil). 
EXAMPLE 13 
57.5 g of diurethane (prepared from 1,4-cyclohexane diisocyanate and 
methanol), 42.1 g of allyl chloride and 22 g of powdered sodium hydroxide 
were reacted in 500 ml of N-methyl-pyrrolidone by the method described in 
Example 1. 
After-stirring time: 15 h at 50.degree. C. 
Yield: 60.5 g (78%) (yellowish oil). 
EXAMPLE 14 
65.6 g of diurethane (prepared from benzyl isocyanate and ethylene glycol), 
63.3 g of benzyl chloride and 20 g of powdered sodium hydroxide were 
reacted in 500 ml of DMF by the method described in Example 1. 
After-stirring time: 15 h at 50.degree. C. 
Yield: 95.5 g (94%), m.p.: 102.degree. C. (colorless crystals of 
isopropanol). 
EXAMPLE 15 
53.3 g of triurethane (prepared from benzyl isocyanate and trimethylol 
propane), 25.3 g of allyl chloride and 18.5 g of powdered potassium 
hydroxide were reacted in 300 ml of tetramethylene sulfone by the method 
described in Example 1. 
After-stirring time: 15 h at 50.degree. C. 
Yield: 50.9 g (78%) (yellowish oil). 
EXAMPLE 16 
49.5 g of N-benzyl-carbamic acid methyl ester, 66.8 g of 
2,4-dinitrochlorobenzene and 13.2 g of powdered sodium hydroxide were 
reacted in 400 ml of DMF by the method described in Example 1. 
After-stirring time: 15 h at 50.degree. C. 
Yield: 37.8 g (38%) (violet resin) 
EXAMPLE 17 
49.5 g of N-benzyl-carbamic acid methyl ester, 12.8 g of powdered sodium 
hydroxide and 6.8 g of triethyl benzyl ammonium chloride were reacted in 
200 ml of benzyl chloride by the method described in Example 1. 
After-stirring time: 3 h at 50.degree. C. 
Yield: 64.3 g (84%), b.p.: 139.degree. C./0.16 mbar (colorless oil). 
EXAMPLE 18 
33 g of N-benzyl-carbamic acid methyl ester, 8.8 g of powdered sodium 
hydroxide and 4.5 g of triethyl benzyl ammonium chloride were reacted in 
100 ml of n-butyl bromide by the method described in Example 1. 
After-stirring time: 3 h at 80.degree. C. 
Yield: 26.1 g (59%), b.p.: 110.degree. C./0.2 mbar (colorless oil). 
EXAMPLE 19 
82.5 g of N-benzyl-carbamic acid methyl ester, 70 g of benzyl chloride, 21 
g of powdered sodium hydroxide and 11.3 g of triethyl benzyl ammonium 
chloride were reacted solvent free by the method described in Example 1. 
Yield: 68.9 g (54%), b.p.: 139.degree. C./0.16 mbar. (colorless oil). 
Although the invention has been described in detail in the foregoing for 
the purpose of illustration, it is to be understood that such detail is 
solely for that purpose and that variations can be made therein by those 
skilled in the art without departing from the spirit and scope of the 
invention except as it may be limited by the claims.