Method for making 1,3,5,2,4,6-trioxatriphosphorinanes

An improved process for preparing 2,4,6-tris(substituted phenoxy)-1,3,5,2,4,6-trioxatriphosphorinanes is realized when the appropriate substituted-phenylphosphorodichloridite is reacted with water in the presence of a trialkyl amine wherein the alkyl groups contain 4 to 8 carbon atoms in acetone as the sole solvent, to provide the desired 2,4,6-tris(substituted phenoxy)-1,3,5,2,4,6-trioxatriphosphorinanes in increased yields and of a higher purity.

BACKGROUND OF THE INVENTION 
Novel stabilizers for organic materials subject to degradation, 
2,4,6-tris(substituted phenoxy)-1,3,5,2,4,6-trioxatriphosphorinanes that 
form effective stabilizer combinations with hindered phenol compounds, 
particularly hydroxyphenylalkyleneyl isocyanurates, have been prepared by 
the reaction of substituted phenylphosphorodichloridites, water and 
triethylamine in tetrahydrofuran. At least one other solvent is required 
to isolate and purify the product for use. A less complex single solvent 
process that also provides improved yields of product of a higher purity 
is desired. 
SUMMARY OF THE INVENTION 
An improved process for preparing 2,4,6-tris(substituted 
phenoxy)-1,3,5,2,4,6-trioxatriphosphorinanes is realized when the 
appropriate substituted-phenylphosphorodichloridite is reacted with water 
in the presence of a trialkyl amine wherein the alkyl groups contain 4 to 
8 carbon atoms, in acetone as the sole solvent, to provide the desired 
2,4,6-tris(substituted phenoxy)-1,3,5,2,4,6-trioxatriphosphorinanes at 
increased yields and of a higher purity. 
DETAILED DESCRIPTION 
Use of this novel process provides a number of advantages over other 
processes and methods that have been used to make 2,4,6-tris(substituted 
phenoxy)-1,3,5,2,4,6-trioxatriphosphorinanes. Improved yields of desired 
product are obtained. The 2,4,6-tris(substituted 
phenoxy)-1,3,5,2,4,6-trioxatriphosphorinane is more readily separated from 
the amine hydrochloride byproduct that forms during the reaction. The 
2,4,6-tris(substituted phenoxy)-1,3,5,2,4,6-trioxatriphosphorinane is in a 
purer state and substantially free of an undesired acid byproduct formed 
when lower trialkyl amines such as triethylamine are used. A less complex 
process comprising less handling and fewer processing steps is realized 
for a savings of energy and labor costs. For example, only one solvent is 
required that is less expensive than solvents previously used. This avoids 
costly solvent recovery, storage, recycling, etc., and eliminates the 
possibility of solvent contamination when more than one solvent is used. 
The 2,4,6-tris(substituted phenoxy)-1,3,5,2,4,6-trioxatriphosphorinanes may 
be represented by the general formula (1) 
##STR1## 
wherein t is t-butyl or t-pentyl and R.sub.1 is hydrogen, primary, 
secondary, and tertiary alkyl radicals containing 1 to 9 carbon atoms such 
as methyl, ethyl, isopropyl, n-butyl, t-butyl, amyl, t-amyl, hexyl; 
heptyl, 2-methylhexyl, 2-ethylhexyl, octyl, isooctyl, and the like; 
cycloalkyl radicals containing 3 to 6 carbon atoms; halogen; C.tbd.N; 
alkoxy radicals containing 1 to 8 carbon atoms, such as methoxy, ethoxy, 
butoxy and the like; phenyl, COOR.sub.2 wherein R.sub.2 is an alkyl 
radical containing 1 to 18 carbon atoms; --CH.sub.2 CH.sub.2 COOR.sub.3 
wherein R.sub.3 is an alkyl radical containing 1 to 18 carbon atoms, and 
--C(CH.sub.3).sub.2 CON(R.sub.4).sub.2 wherein R.sub.4 is an alkyl group 
containing 1 to 9 carbon atoms. 
Preferably t is t-butyl and R.sub.1 is hydrogen, an alkyl radical 
containing 1 to 4 carbon atoms, alkoxy radicals containing 1 to 4 carbon 
atoms, --COOR.sub.2, --CH.sub.2 CH.sub.2 COOR.sub.3, and 
--C(CH.sub.3).sub.2 CON(R.sub.4).sub.2 radicals wherein R.sub.2, R.sub.3 
and R.sub.4 are alkyl radicals containing 1 to 4 carbon atoms. 
Typical 2,4,6-tris(substituted phenoxy)-1,3,5,2,4,6-trioxatriphosphorinanes 
are: 2,4,6-tris(2,6-di-t-butylphenoxy)-1,3,5,2,4,6-trioxatriphosphorinane 
and 2,4,6-tris(2,6-di-t-butyl-4-substituted 
phenoxy)-1,3,5,2,4,6-trioxatriphosphorinanes wherein the radicals 
substituted at the 4-position are those described above. Typical compounds 
are 
2,4,6-tris(2,6-di-t-butyl-4-methylphenoxy)-1,3,5,2,4,6-trioxatriphosphorin 
ane, 
2,4,6-tris(2,6-di-t-butyl-4-ethylphenoxy)-1,3,5,2,4,6-trioxatriphosphorina 
ne, 
2,4,6-tris(2,6-di-t-butyl-4-propylphenoxy)-1,3,5,2,4,6-trioxatriphosphorin 
ane, 
2,4,6-tris(2,6-di-t-butyl-4-isopropylphenoxy)-1,3,5,2,4,6-trioxatriphospho 
rinane, 
2,4,6-tris(2,6,-di-t-butyl-4-n-butylphenoxy)-1,3,5,2,4,6-trioxatriphosphor 
inane, 
2,4,6-tris(2,6-di-t-butyl-4-isoamylphenoxy)-1,3,5,2,4,6-trioxatriphosphori 
nane, 
2,4,6-tris(2,6-di-t-butyl-4-methoxyphenoxy)-1,3,5,2,4,6-trioxatriphosphori 
nane, 
2,4,6-tris(2,6-di-t-butyl-4-ethoxyphenoxy)-1,3,5,2,4,6-trioxatriphosphorin 
ane, 
2,4,6-tris(2,6-di-t-butyl-4-carbomethoxyphenoxy)-1,3,5,2,4,6-trioxatriphos 
phorinane, 
2,4,6-tris(2,4,6-tri-t-butylphenoxy)-1,3,5,2,4,6-trioxatriphosphorinane, 
2,4,6-tris[2,6-di-t-butyl-4-(2-carboethoxyethyl)phenoxy]-1,3,5,2,4,6-triox 
atriphosphorinane, 
2,4,6-tris[2,6-di-t-butyl-4-(1-methyl-1-diethylcarbamoylethyl)phenoxy]-1,3 
,5,2,4,6-trioxatriphosphorinane, and 
2,4,6-tris[2,6-di-t-butyl-4-(2-carbooctadecyloxyethyl)phenoxy]-1,3,5,2,4,6 
-trioxatriphosphorinane. 
To make the 2,4,6-tris(substituted 
phenoxy)-1,3,5,2,4,6-trioxatriphosphorinanes, a substituted 
phenylphosphorodichloridite is reacted with water and a tertiary alkyl 
amine in acetone at low temperatures for short periods of time; and the 
resulting 2,4,6-tris(substituted 
phenoxy)-1,3,5,2,4,6-trioxatriphosphorinane is readily obtained by 
filtering the reaction mixture, to separate the 
1,3,5,2,4,6-trioxatriphosphorinane and washing the crude product with 
acetone. 
Substituted phenylphosphorodichloridites used in the process of the 
invention include those substituted at the 2,6- and 2,4,6-positions on the 
phenyl group. The 2- and 6-positions are substituted with the t-butyl or 
t-pentyl groups, while the 4-position may be substituted with the alkyl, 
alkoxy, carboxyester, and like radicals as set forth for the 
##STR2## 
radical above. These substituted phenylphosphorodichloridites are readily 
prepared by reacting the alkylphenol with a molar excess of PCl.sub.3 to 
form the substituted phenylphosphorodichloridite that may be isolated by 
distillation. Procedures for preparing the substituted 
phenylphosphorodichloridite are found in U.S. Pat. No. 3,271,481. One of 
the advantages of this invention is that isolation of the substituted 
phenylphosphorodichloridite by distillation is not required, and the 
substituted phenylphosphorodichloridite may be prepared in situ and used 
per se in the improved method of this invention. 
Typical substituted phenylphosphorodichloridite reactants include 
2,6-di-t-butyl-4-methylphenylphosphorodichloridite, 
2,6-di-t-butyl-4-ethylphenylphosphorodichloridite, 
2,6-di-t-butyl-4-propylphenylphosphorodichloridite, 
2,4,6-tri-t-butylphenylphosphorodichloride, 
2,6-di-t-butyl-4-t-butylphenylphosphorodichloridite, 
2,6-di-t-butyl-4-methoxyphenylphosphorodichloridite, 
2,6-di-t-butyl-4-ethoxyphenylphosphorodichloridite, 
2,6-di-t-butyl-4-carbomethoxyphenylphosphorodichloridite, 
2,6-di-t-butylphenylphosphorodichlororidite, 
2,6-di-t-butyl-4-(1-methyl-1-diethylcarbamoylethyl)phenylphosphorodichlori 
dite, 2,6-di-t-butyl-4-(2-carboethoxyethyl)phenylphosphorodichloridite, 
2,6-di-t-butyl-4-nonylphenylphosphorodichloridite, and the like. 
The amines are trialkylamines wherein the alkyl radicals contain 4 to 8 
carbon atoms, including for example, tributylamine, tripentylamine, 
triisopentylamine, trihexylamine, triheptylamine, trioctylamine, and the 
like. The preferred tributylamine has a specific gravity of 0.775.+-.0.005 
at 20.degree. C., less than 0.1 weight percent water and a color value 
measured at 420 nanometers of less than 0.25 absorbance units. 
The molar ratios of the reactants normally used are about one mole of the 
substituted phenylphosphorodichloridite, one mole of water and two moles 
of the amine. While these proportions may be varied within a range of 
about 1 to 0.8 to 2.0 of water and 0.5 to 10 of amine, better yields are 
obtained when about a 1:1:2 mol ratio is observed. Of course, an excess of 
any reactant may be used but good yields will depend on there being at 
least about one mol of water and one mole of amine present. The amount of 
acetone used will vary from 3.5 to 25 moles based on one mole of 
substituted phenylphosphorodichloridite used. 
The reaction is quite rapid and usually is conducted at about 25.degree. C. 
to control the reaction rate, although the reaction temperature may vary 
from about 0.degree. C. to 50.degree. C. The reaction products prepared in 
accordance with this novel process normally need only be filtered as the 
reaction product has precipitated from the solvent, is separated by 
filtration, washed with acetone, and dried. 
The structures of the 2,4,6-tris(substituted 
phenoxy)-1,3,5,2,4,6-trioxatriphosphorinanes are confirmed by infrared and 
nuclear magnetic resonance spectra. Molecular weights were determined and 
confirmed by field desorption mass spectra (FD/MS) and fast atom 
bombardment mass spectra (FAB/MS). In some cases elemental analysis for 
carbon, hydrogen and phosphorus was done and the amounts found were 
consistent with the formula of the material.

The following Example is a typical preparation of the phosphorinanes by a 
process used prior to this invention. 
EXAMPLE I 
2,4,6-tris(2,6-di-t-butyl-4-methylphenoxy)-1,3,5,2,4,6-trioxatriphosphorina 
ne 
6.0 grams (0.019 mol) of 2,6-di-t-butyl-4-methylphenylphosphorodichloridite 
and 3.78 grams (0.037 mol) of triethylamine were dissolved in 100 ml of 
tetrahydrofuran, and the solution was cooled to 0.degree.-5.degree. C. 
0.34 gram (0.019 mol) of water was added to the solution and the mixture 
was stirred for 0.5 hour. The resulting reaction mixture was filtered and 
the filtrate was evaporated to a dry white glass. The dry product was 
stirred twice with saturated aqueous sodium bicarbonate solution for ten 
minutes, filtered, washed with water and air dried to provide the white 
solid (4.04 grams) 84% of theoretical yield. After washing in methanol, 
the solid had a mp 170.degree.-184.degree. C., and the melt was cloudy and 
had an orange color. It was determined by infra red analysis that this 
phosphorinane was contaminated with an acidic byproduct derived from the 
phosphorodichloridite. Calculated for C.sub.15 H.sub.23 O.sub.2 P: C, 
67.65; H, 8.71; P,11/63. Found: C, 67.7; H, 8.68; P, 11.53. FD/MS: 799 
(actual 798.96), 266 
##STR3## 
219 
##STR4## 
FAB/MS: 799. IR (Nujol) 950, 930 (P-O), 848, 820 cm.sup.-1. .sup.1 H 
NMR(CDCl.sub.3): 1.35 (S,18H), 1.47 (S,36H), 2.26 (S, 3H), 2.29 (S, 6H), 
7.07 (S, 2H), 7.11 (S, 4H). .sup.31 P NMR (CDCl.sub.3): 120.0 (d,J=10, 
2P), 127.9 (t,J=10, 1P). 
EXAMPLE II 
2,4,6-tris(2,6-di-t-butyl-4-methylphenoxy)-1,3,5,2,4,6-trioxatriphosphorina 
ne 
6.31 grams (0.06 mole) of triethylamine was charged to a reactor. 10.0 
grams (0.032 mol) of 2,6-di-t-butyl-4-methylphenylphosphorodichloridite 
dissolved in 110 ml of acetone was then added to the reactor and the 
solution was adjusted to 20.degree.-25.degree. C. 0.56 gram (0.037 mol) of 
water in 15 ml of acetone was added to the solution in the reactor and the 
mixture was stirred for 0.5 hour. The resulting reaction mixture contained 
a white solid precipitate of both the 
2,4,6-tris(2,6-di-t-butyl-4-methylphenoxy)-1,3,5-2,4,6-trioxatriphosphorin 
anes and triethylamine hydrochloride. The reaction product was filtered, 
the recovered solid product was washed with water to wash out the 
triethylamine hydrochloride by-product, and air dried to provide the white 
solid, 45% yield, melting point 181.degree.-185.degree. C. The melt was 
cloudy and had an orange color. The presence of the undesired acidic 
by-product obtained when triethylamine is used is determined by infra red. 
EXAMPLE III p 5.77 grams (0.031 mol) of tributylamine was charged to a 
reaction vessel equipped with stirring, heating and cooling means. 5 grams 
(0.016 mol) of 2,6-di-t-butyl-4-methylphenylphosphorodichloridite 
dissolved in 65 ml of acetone was added to the reactor. With the solution 
at a temperature of 20.degree.-25.degree. C., 0.28 grams (0.016 mol) of 
water dissolved in 10 ml of acetone was slowly added, with stirring, to 
the reaction mixture and stirred for 0.5 hour. The 
2,4,6-tris(2,6-di-t-butyl-4-methylphenoxy)-1,3,5,2,4,6-trioxatriphosphorin 
ane crystallized from the reaction mixture and was removed by filtration. 
The tributylamine hydrochloride by-product was soluble in the acetone, as 
compared to Example II where the triethylamine hydrochloride precipitated 
out with the phosphorinane and had to be removed in an additional step. 
The white solid was washed with acetone to yield 3.33 grams of 
2,4,6-tris(2,6-di-t-butyl-4-methylphenoxy)-1,3,5,2,4,6-trioxatriphosphorin 
ane for a yield of 80%. This product was free of tributylamine 
hydrochloride. The melting point was 177.degree.-181.degree. C., the melt 
was clear and free of acidic by-product impurity. This is to be compared 
to Example I, where the use of triethylamine rather than tributylamine 
resulted in the acid byproduct. 
EXAMPLE IV 
Example III above was repeated with the difference that methyl ethyl ketone 
was used as the solvent rather than acetone. In this Example, the 
2,4,6-tris(2,6-di-t-butyl-4-methylphenoxy)-1,3,5,2,4,6-trioxatriphosphorin 
ane did not crystallize or precipitate from the reaction mixture but was 
dissolved in the methyl ethyl ketone. The reaction solution had to be 
heated to strip off the methyl ethyl ketone. After heating the reaction to 
dryness, the residue was stirred for 0.5 hour in 75 ml of acetonitrile to 
separate the insoluble phosphorinane from the soluble tributylamine 
hydrochloride. The resulting white solid was removed by filtration and 
washed with acetonitrile. 2.62 grams of 
2,4,6-tris(2,6-di-t-butyl-4-methylphenoxy)-1,3,5,2,4,6-trioxatriphosphorin 
ane was obtained for a yield of only 63 percent and a melting point of 
181.degree.-185.degree. C. This Example and Example I, demonstrate the 
undesirable results obtained with solvents other than acetone. The melt 
was cloudy and yellow colored. 
When Example III is repeated with 
2,4,6-tri-t-butylphenylphosphorodichloridite and/or with other higher 
alkyl amines, as tripentylamine, triisopentylamine, trihexylamine, 
triheptylamine and trioctylamine, yields of about 80% are readily 
obtained. On a cost and handling basis, tributylamine is preferred. 
To further demonstrate the advantages of this invention using acetone as 
the solvent and tributylamine as the hydrogen chloride acceptor, the 
preparation of the substituted phenylphosphorodichloridite may be done in 
situ and used per se in the phosphorinane formation as shown in Example V. 
EXAMPLE V 
2,6-di-t-butyl-4-methylphenol (40 g, 0.18 moles) and tributylamine (100.9 
g, 0.55 moles) were charged to a reaction vessel and phosphorus 
trichloride (24.9 g, 0.18 moles) was added. After heating this mixture for 
1 hour at 110.degree. C., the mixture was cooled to 25.degree. C. and 100 
ml acetone was added. Water (3.27 g, 0.18 moles) dissolved in 25 ml of 
acetone was dropped in slowly to maintain the reaction temperature below 
30.degree. C. A cooling bath may be used if needed. After addition was 
complete, the mixture was stirred for 0.5 hour. The solid was removed by 
filtration, washed with acetone and was air dried to give an 82% yield of 
2,4,6-tris(2,6-di-t-butyl-4-methylphenoxy)-1,3,5,2,4,6-trioxatriphosphorin 
ane, melting point of 176.degree.-181.degree. C. 
Example V was repeated using tributylamine that had a specific gravity of 
0.785 and an absorbance of 0.55 unit at 420 nanometers. A reduced product 
yield of only 68.5% was obtained that had a melting point of 
173.degree.-182.degree. C. 
Organic materials stabilized by the 
2,4,6-tris(2,6-di-t-butyl-4-methylphenoxy)-1,3,5,2,4,6-trioxatriphosphorin 
ane prepared in accordance with this invention include both natural and 
synthetic polymers. For example, the phosphorinane stabilizers are useful 
for the stabilization of cellulosic materials; natural rubber; halogenated 
rubber, conjugated diene polymers like polyisoprene, polychloroprene; 
vinyl polymers such as poly(vinyl chloride); hompolymers and copolymers of 
acrylate monomers; epihalohydrin polymers; polyether-, polyester- or 
polyol-derived polyurethanes; acetal homopolymers and copolymers; 
polycarbonates; polyesters such as polyethylene terephthalate; polyamides; 
epoxy resins, and the like. 
In addition to polymeric materials, the phosphorinane compounds may be used 
to stabilize a wide variety of other organic materials. Such materials 
include: waxes, synthetic and petroleum-derived lubricating oils and 
greases; animal oils such as, for example, fat, tallow, lard, codliver 
oil, sperm oil; vegetable oils such as castor, linseed, peanut, palm, 
cotton seed, and the like; fuel oil; diesel oil, gasoline and the like.