This invention relates to a novel class of organosilanes. The characteristic feature of these silanes is the presence of a hydantoin residue that is bonded to silicon through an alkylene group.

BACKGROUND OF THE INVENTION 
This invention relates to a novel class of organosilanes. The 
characteristic feature of these silanes is the presence of a hydantoin 
residue that is bonded to silicon through an alkylene group. 
SUMMARY OF THE INVENTION 
The organosilanes of this invention exhibit the general formulae 
##STR1## 
wherein R.sup.1 is selected from the group consisting of alkyl, aryl, 
cyanoalkyl, trifluoropropyl, alkenyl, alkynyl and halophenyl; R.sup.2 is 
selected from the group consisting of alkyl, alkaryl and cycloalkyl; 
R.sup.3 is alkylene; R.sup.4 and R.sup.5 are individually selected from 
the group consisting of hydrogen, alkyl, aryl, aralkyl and alkaryl; 
R.sup.6 is 
##STR2## 
or is selected from the same group as R.sup.4 and n is 0, 1, 2 or 3 with 
the proviso that any alkyl or alkylene group contains from 1 to 12 carbon 
atoms and any alkenyl or alkynyl group contains from 2 to 12 carbon atoms. 
This invention also provides a method for preparing a hydantoinyl silane, 
said method consisting essentially of the following steps: 
(1) Reacting substantially equimolar amounts of (a) an anhydrous alkali 
metal salt of a hydantoin represented by the general formula 
##STR3## 
wherein M represents an alkali metal and (b) a haloalkylsilane represented 
by the general formula 
##STR4## 
in a reaction medium comprising a dipolar, aprotic liquid; 
(2) maintaining the mixture containing the hydantoin salt and said 
haloalkylsilane at a temperature of from ambient to the boiling point of 
said mixture for a period of time sufficient to obtain a substantially 
complete reaction, and 
(3) isolating said hydantoinyl silane from the reaction mixture. 
DETAILED DESCRIPTION OF THE INVENTION 
The novel silanes of this invention can be prepared using conventional 
procedures employed for reacting halosilanes with compounds containing a 
labile proton. A preferred method involves the reaction of an anhydrous 
alkali metal salt of hydanotoin or one of the substituted hydantoins 
represented by the formula 
##STR5## 
with a haloalkylsilane represented by the formula 
##STR6## 
wherein X represents chlorine, bromine or iodine. This reaction is 
preferably conducted in the presence of a dipolar aprotic organic liquid 
medium which is a solvent for the aforementioned alkali metal salt of the 
hydantoin. Suitable dipolar aprotic liquids include N,N-dimethylformamide, 
N-methylpyrrolidone and dimethylsulfoxide. 
Since the reaction between the hydantoin salt and the haloalkyl silane may 
be exothermic, it is preferable to first dissolve the hydantoin salt in 
the liquid reaction medium and gradually add the haloalkylsilane to the 
resultant solution under an inert atmosphere such as nitrogen to exclude 
even trace amounts of water, which would rapidly hydrolyze the alkoxy 
groups present on the haloalkylsilane. It is often desirable to heat the 
reaction mixture at temperatures of from 40.degree. to about 100.degree. 
C. for from 0.5 to 5 hours or longer to ensure that the reaction is 
complete. The reaction product is often soluble in the reaction medium, in 
which instance the product is readily isolated by filtering to remove the 
solid alkali metal halide byproduct and distilling the dipolar aprotic 
liquid under reduced pressure to minimize heat-induced decomposition of 
the desired product. 
The product of the aforementioned reaction contains one silicon atom and 
one hydantoin residue that is bonded to silicon through an alkylene group 
represented by R.sup.3 in the foregoing formula. Compounds containing 3 
hydrocarbyl and 1 hydrocarbyloxy group bonded to silicon are readily 
converted to the corresponding 
bis(hydantoinylalkyl)tetrahydrocarbyldisiloxane by hydrolysis in the 
presence of a methanol-water or ethanol-water mixture containing a trace 
amount of an alkali metal hydroxide such as potassium hydroxide. 
THe hydantoin employed to prepare the compounds of this invention can be 
unsubstituted, in which instance the substituents represented by R.sup.4, 
R.sup.5 and R.sup.6 in the foregoing formulae are hydrogen. Alternatively, 
one can employ any of the available substituted hydantoins or a compound 
containing the desired substituents can be prepared using synthetic 
procedures and reactions disclosed in the chemical literature. 
Representative substituted hydantoins which are commercially available or 
have been reported in the chemical literature include 
5,5-dimethylhydantoin 
5,5-diphenylhydantoin 
5-ethyl-5-(2-methylbutyl)hydantoin 
5-phenylhydantoin 
The synthesis of hydantoin, also referred to as 2,4-diketoiminazolidine, 
and a number of substituted hydantoins, is described in a text entitled 
"Chemistry of Carbon Compounds" edited by E. H. Rodd (Elsiner Publishing 
Company, 1957) and in an article by E. Ware [Chemical Reviews 46, 403-470 
(1950)].

The following examples describe the preparation of 4 preferred species 
selected from the present class of novel silanes and disiloxanes. These 
examples should not be considered as limiting the scope of the 
accompanying claims. 
EXAMPLE 1--Preparation of 5,5-dimethyl-3-trimethoxysilylpropyl Hydantoin 
A mixture containing 12.8 g (0.1 mole) 5,5-dimethylhydantoin, 5.6 g (0.1 
mole) potassium hydroxide and 100 cc ethanol was heated to the boiling 
point until a clear solution was obtained. The ethanol was then evaporated 
under reduced pressure to isolate the solid, anhydrous salt. The salt was 
combined with 100 cc of dry N,N-dimethylformamide and the resultant 
mixture was heated at 50.degree. C. until a clear solution formed. A 19.8 
g (0.1 mole) portion of chloropropyl trimethoxysilane was then added 
dropwise to the aforementioned salt solution under a nitrogen atmosphere 
with stirring. The temperature of the reaction mixture increased slightly 
during the addition, which is indicative of an exothermic reaction, and a 
white precipitate (potassium chloride) began to form when the silane 
addition was begun. Following completion of the addition the reaction 
mixture was heated at 95.degree. C. for three hours. Analysis by vapor 
phase chromatography of the liquid phase demonstrated that the initial 
chloropropyl trimethoxysilane had been converted to a product exhibiting a 
high retention time. The reaction mixture was then cooled and filtered, 
following which the liquid phase was distilled to remove the 
N,N-dimethylformamide. A second fraction was collected at a temperature of 
194.degree. C. and a pressure of 4 mm of mercury and subsequently 
solidified to a white solid. Analysis by vapor phase chromatography 
indicated that this material was 98% pure and contained a trace amount of 
the initial hydantoin. The infra-red spectrum of the material was 
consistent with the proposed structure 
##STR7## 
The product was found to contain 9.74% by weight of silicon and 9.92% 
nitrogen. The calculated values for the expected product are 9.64% silicon 
and 9.66% nitrogen. 
EXAMPLE 2--Preparation of 3-Dimethoxymethylsilylpropylhydantoin 
A mixture containing 10.0 g (0.1 mole) hydantoin, 5.6 g (0.1 mole) 
potassium hydroxide and 100 cc ethanol was heated to the boiling point 
until a clear solution was obtained. The resultant salt was then isolated 
and dried as described in the preceeding example, following which it was 
solubilized in 100 cc of anhydrous N,N-dimethylformamide and reacted with 
18.2 g of chloropropylmethyldimethoxysilane under a nitrogen atmosphere 
using dropwise addition. The reaction mixture was heated at 110.degree. C. 
for about sixteen hours following completion of the silane addition. The 
reaction mixture was then cooled and filtered to remove the potassium 
chloride byproduct. Analysis of the liquid phase by vapor phase 
chromatography demonstrated that the original silane had been consumed and 
replaced by a material having a significantly longer retention time. The 
desired product was recovered following distillation to remove the 
N,N-dimethylformamide. 
EXAMPLE 3--Preparation of 
Bis[5,5-dimethylhydantoin-3-yl)propyl]tetramethyldisiloxane 
A sample of 5,5-dimethyl-3-dimethylmethoxysilylpropylhydantoin was prepared 
and isolated using the general procedure described in the preceeding 
examples with 0.1 mole of each of the three reagents, namely 
5,5-dimethylhydantoin, 3-chloropropyldimethylmethoxysilane and potassium 
hydroxide. A 24.4 g portion of the final product was dissolved in a 
mixture of 5.4 g of water and 300 cc methanol containing one pellet of 
potassium hydroxide. The resultant mixture was stirred at ambient 
temperature for 16 hours, at which time the methanol-water mixture was 
removed by distillation under reduced pressure. The identity of the final 
product as a disiloxane was confirmed by its infra-red spectrum and by 
vapor phase chromatography. 
EXAMPLE 4--Preparation of 
1,3-Bis(trimethoxysilylpropyl)-5,5-dimethylhydantoin 
A 2.4 g portion of a dispersion containing 50% by weight of sodium hydride 
in a liquid paraffin was added in portions under an inert atmosphere to a 
solution containing 14.5 g (0.05 mole) 
5,5-dimethyl-3-trimethoxysilylpropyl hydantoin and 150 cc of anhydrous 
N,N-dimethylformamide. The temperature of the reaction mixture was 
maintained at from 15.degree. to 20.degree. C. during the addition of the 
hydride. Following completion of the addition the mixture was stirred 
until hydrogen evolution ceased, at which time it was heated to 85.degree. 
C., and 98.8 g of chloropropyltrimethoxysilane were added dropwise to the 
reaction mixture. A white precipitate formed as the addition progressed. 
Following completion of the addition the reaction mixture was heated at 
95.degree. C. for 16 hours, at which time the reaction mixture was cooled, 
filtered and the liquid phase distilled under reduced pressure to remove 
the N,N-dimethylformamide. The liquid paraffin was washed from the product 
using hexane. The identity of the residue as the expected silylhydantoin 
was confirmed using infra-red and nuclear magnetic resonance spectroscopy. 
The silanes and disiloxanes of this invention are particularly useful as 
coupling agents for bonding glass fibers to organic resins and as 
self-bonding adhesion promoters for room temperature curable silicone 
adhesives. Some prior art room temperature curable polysiloxane products 
employing an acetoxysilane as the curing agent require a primer to achieve 
adequate adhesion with the substrate to which they are applied. Primers 
are not required using the hydantoinyl silanes of this invention.