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CHEMISTRY
E. V. KUZNETSOV and M. I. BAKHITOV
ADDITION OF DIALKYL PHOSPHOROUS ACIDS TO 3,3′-DIMETHOXY-DIPHENYL-4,4′- AND DIPHENYLMETHANE-4,4′-DIISOCYANATES
(Presented by Academician B. A. Arbuzov, 26 VI 1961)
We have previously shown that dialkyl phosphorous acids, in the presence of sodium alcoholate, readily add to 1,5-naphthylene-, 1,6-hexamethylene-, and 2,4-toluylene diisocyanates \((^{1–2})\). Continuing investigations in this direction, we decided to study the addition of dialkyl phosphorous acids to 3,3′-dimethoxy-diphenyl-4,4′- and diphenylmethane-4,4′-diisocyanates.
It was found that dialkyl phosphorous acids, in the presence of a small amount of sodium, also add readily to these diisocyanates. In general form, the interaction of diisocyanates with dialkyl phosphorous acids can be represented by the following equation:
\[ (\mathrm{RO})_2\mathrm{POH} + \mathrm{Na} \rightarrow (\mathrm{RO})_2\mathrm{PONa} \]
\[ \begin{aligned} &\mathrm{R} \begin{matrix} \diagup\ \mathrm{N}=\mathrm{C}=\mathrm{O}\\ \diagdown\ \mathrm{N}=\mathrm{C}=\mathrm{O} \end{matrix} +(\mathrm{RO})_2\mathrm{POH} \xrightarrow{(\mathrm{RO})_2\mathrm{PONa}} \mathrm{R} \begin{matrix} \diagup\ \mathrm{N}=\mathrm{C}-\mathrm{OH}\\ \diagdown\ \mathrm{N}=\mathrm{C}=\mathrm{O} \end{matrix} \begin{matrix} \mathrm{O}=\mathrm{P}(\mathrm{OR})_2\\ | \end{matrix} + \\[1em] &\quad +(\mathrm{RO})_2\mathrm{POH} \xrightarrow{(\mathrm{RO})_2\mathrm{PONa}} \mathrm{R} \begin{matrix} \diagup\ \mathrm{N}=\mathrm{C}-\mathrm{OH}\\ \diagdown\ \mathrm{N}=\mathrm{C}-\mathrm{OH} \end{matrix} \begin{matrix} \mathrm{O}=\mathrm{P}(\mathrm{OR})_2\\ |\\ \\ |\\ \mathrm{O}=\mathrm{P}(\mathrm{OR})_2 \end{matrix} \rightleftarrows \mathrm{R} \begin{matrix} \diagup\ \mathrm{NHCOPО}(\mathrm{OR})_2\\ \diagdown\ \mathrm{NHCOPО}(\mathrm{OR})_2 \end{matrix} \end{aligned} \]
The mechanism of this reaction is analogous to the mechanism of the interaction of dialkyl phosphorous acids, in the presence of sodium alcoholates, with 1,5-naphthylene diisocyanate.
The equilibrium is strongly shifted toward formation of the ketone form \((^3)\). Thus, for example, by the action of sodium ethoxide on a benzene solution of the 3,3′-dimethoxy-4,4′-diphenyl bis-diethyl ester of amidophosphonuravic acid, the sodium derivative was obtained according to the scheme:
\[ \begin{aligned} &(\mathrm{C}_2\mathrm{H}_5\mathrm{O})_2\mathrm{POCONH} \ \mathrm{C}_6\mathrm{H}_3(\mathrm{OCH}_3) -\mathrm{C}_6\mathrm{H}_3(\mathrm{OCH}_3) \ \mathrm{NHCOPО}(\mathrm{OC}_2\mathrm{H}_5)_2 +2\mathrm{C}_2\mathrm{H}_5\mathrm{ONa} \rightarrow \\[0.5em] &\rightarrow (\mathrm{C}_2\mathrm{H}_5\mathrm{O})_2\mathrm{POCONNa} \ \mathrm{C}_6\mathrm{H}_3(\mathrm{OCH}_3) -\mathrm{C}_6\mathrm{H}_3(\mathrm{OCH}_3) \ \mathrm{NCOPО}(\mathrm{OC}_2\mathrm{H}_5)_2\mathrm{Na} +2\mathrm{C}_2\mathrm{H}_5\mathrm{OH}. \end{aligned} \]
In this case the addition product reacts with sodium ethoxide in the ketone form. Studies in this direction are continuing. All the synthesized substances crystallize on prolonged standing, with the exception of products Nos. 9–12 (Table 1).
Table 1
| No. | R | m.p.,* °C | Phosphorus content, %, found | Phosphorus content, %, calculated | Nitrogen content, %, found | Nitrogen content, %, calculated | Yield, % | Empirical formula |
|---|---|---|---|---|---|---|---|---|
\[ (\mathrm{RO})_{2}\mathrm{POCONH} \ \langle\!\langle\mathrm{C}_{6}\mathrm{H}_{4}\rangle\!\rangle -\mathrm{CH}_{2}- \langle\!\langle\mathrm{C}_{6}\mathrm{H}_{4}\rangle\!\rangle \mathrm{NHCOP(O)(OR)}_{2} \]
| No. | R | m.p.,* °C | Phosphorus content, %, found | Phosphorus content, %, calculated | Nitrogen content, %, found | Nitrogen content, %, calculated | Yield, % | Empirical formula |
|---|---|---|---|---|---|---|---|---|
| 1 | CH₃ | 155–156 | 12.92 12.80 |
13.19 | 5.74 5.70 |
5.95 | 70 | C₁₉H₂₄O₈N₂P₂ |
| 2 | C₂H₅ | 115–116 | 11.40 11.45 |
11.78 | 5.21 5.18 |
5.32 | 76 | C₂₃H₃₂O₈N₂P₂ |
| 3 | n-C₃H₇ | 88–89 | 10.53 10.50 |
10.65 | 4.67 4.57 |
4.81 | 83 | C₂₇H₄₀O₈N₂P₂ |
| 4 | iso-C₃H₇ | 178–179, with considerable decomposition | 10.62 10.45 |
10.65 | 4.70 4.68 |
4.81 | 88 | C₂₇H₄₀O₈N₂P₂ |
| 5 | n-C₄H₉ | 68–70 | 9.49 9.38 |
9.71 | 4.19 4.23 |
4.38 | 66 | C₃₁H₄₈O₈N₂P₂ |
| 6 | iso-C₄H₉ | 102–103 | 9.51 9.37 |
9.71 | 4.09 4.13 |
4.38 | 84 | C₃₁H₄₈O₈N₂P₂ |
| 7 | ClCH₂CH₂ | 111–113 | 9.04 9.00 |
9.33 | 3.96 4.08 |
4.21 | 85 | C₂₃H₂₈O₈N₂P₂Cl₄ |
\[ (\mathrm{RO})_{2}\mathrm{POCONH} \ \langle\!\langle\mathrm{C}_{6}\mathrm{H}_{3}(\mathrm{OCH}_{3})\rangle\!\rangle - \langle\!\langle\mathrm{C}_{6}\mathrm{H}_{3}(\mathrm{OCH}_{3})\rangle\!\rangle \mathrm{NHCOP(O)(OR)}_{2} \]
| No. | R | m.p.,* °C | Phosphorus content, %, found | Phosphorus content, %, calculated | Nitrogen content, %, found | Nitrogen content, %, calculated | Yield, % | Empirical formula |
|---|---|---|---|---|---|---|---|---|
| 8 | CH₃ | 102–104 | 11.77 11.86 |
12.01 | 5.12 5.09 |
5.42 | 62 | C₂₀H₂₆O₁₀N₂P₂ |
| 9 | C₂H₅ | 148–150 | 10.38 10.49 |
10.83 | 4.45 4.67 |
4.89 | 68 | C₂₄H₃₄O₁₀N₂P₂ |
| 10 | iso-C₃H₇ | 146 | 9.76 9.70 |
9.86 | 4.45 4.27 |
4.45 | 79 | C₂₈H₄₂O₁₀N₂P₂ |
| 11 | iso-C₄H₉ | 125–126 | 8.92 8.64 |
9.06 | 3.93 3.86 |
4.09 | 84 | C₃₂H₅₀O₁₀N₂P₂ |
| 12 | ClCH₂CH₂ | 127–128 | 8.37 8.33 |
8.73 | 3.61 3.48 |
3.94 | 86 | C₂₄H₃₀O₁₀N₂P₂Cl₄ |
* The melting point was determined in sealed capillaries.
They were purified by twofold recrystallization at low temperature from methyl alcohol. These are white crystalline substances, readily soluble in alcohol, benzene, dioxane, acetone, etc. They are insoluble in water. The properties of the addition products are presented in Table 1.
Thus, the addition of dialkyl phosphorous acids to 3,3′-dimethoxy-diphenyl-4,4′- and diphenylmethane-4,4′-diisocyanates has been studied.
In conclusion, we consider it our duty to express our gratitude to B. M. Tsi-gin for kindly providing the diisocyanates for our investigations.
Kazan Chemical-Technological Institute
named after S. M. Kirov
Received
20 VI 1961
References Cited
- E. V. Kuznetsov, M. I. Bakhitov, DAN, 134, 830 (1960).
- E. V. Kuznetsov, M. I. Bakhitov, ZhOKh, 31, issue 9, 1391 (1960).
- V. V. Alekseev, M. S. Malinovskii, ZhOKh, 30, 2967 (1960).