ALLENC. BUCK AND HERMAN P. LANDLMLA
2396
Vol. 70
[CONTRIBUTION FROM THE MORLEY CHEMICAL LABORATORY O F WESTERN RESERVE UNIVERSITY]
Thiophosphoric Amides : Aminolysis B Y ALLEN c . BUCK^
AND
Mixed thiophosphoric triamides of the type (RNH)ZPS(NHRl) where R is an aromatic radical and RI an aliphatic radical have been prepared by Michaelis1 by the stepwise aminolysis of thiophosphoryl chloride
+ PSCla + (R1NH)PSClz + RlNH2.HCl (R1NH)PSCIi + 4RNHz + (RlNH)P(NHR)z + 2RNHz.HCl S
2Rln”z
HERMAN P.
LANKELMA
concurrent formation of a mixed triamide by loss of hydrogen sulfide between dithiophosphoric dianilide and benzylamine and displacement of aniline by benzylamine
+
(C6HjXH)zPSSH 3CsHsCHzNHz --+ (Ce”CHzNH)3PS 2CsHsKHz
(1)
+
+ HzS
(6)
The displacement of aniline by benzylamine with the formation of benzylamine triamide in (2) each of these cases suggested the possibility of a similar reaction occurring also with a triamide. Xichaelis could not use this method to prepare The reaction of triamides with primary aliphatic mixed triamides in which both radicals were aro- amines and with primary aromatic amines was matic since the intermediate, RNHPSC12, lost hy- therefore studied. This reaction could lead to drogen chloride to give RN=PSCl. S S A new approach to the preparation of mixed mixed triamides (RNH)ZP(NHR’) and (RNH)Pthiophosphoric triamides was suggested by the (NHR/)2by partial displacement or to (RNH)sPS addition of aniline to dimeric thiophosphoric anil by complete displacement. The results of this anilide2 The addition of amines to dimeric thio- study are shown in Table I. phosphoric anil anilide could yield mixed thiophosThe reaction of thiophosphoric trianilide with phoric triamides tributylamine and with dimethylaniline was tried to determine the effect of tertiary amines, which S (C6HjY--P--n”CsH5)2 RNHz + could not enter into displacement reactions. I 1 When thiophosphoric trianilide was heated a t S 130’ in a large excess of tributylamine, hydrogen 2 (CsH6NH)zP-XHR (3) sulfide was continuously evolved for twenty hours. When RNHz in equation (3) was benzylamine, in Aniline and the phosphate ion were identified as excess, the product a t temperatures of 30 and 60’ decomposition products. Dimethylaniline prowas a mixture containing triamides of both benzyl- moted a similar decomposition, but required a amine and aniline. No pure mixed triamide much longer reaction time. I n neither case could could be isolated. When the reaction tempera- any thiophosphoric trianilide be recovered. ture was raised to 130’ tribenzylthiophosphoric It is apparent that this decomposition not only amide was isolated in good yield. This product resulted in the rupture of nitrogen-phosphorus could have formed only through the addition of bonds, but that the rate at which these bonds were benzylamine to dimeric thiophosphoric anil anil- broken was related to the basicity of the tertiary ide and the replacement of aniline by benzylamine amine used. It would follow that thiophosphoric triamides heated in excess primary aliphatic or S (CeH&-P-~HCsHj)n GCsHbCHzNH2 -3 aromatic amines would have nitrogen-phosphorus I I bonds severed in an analogous fashion. In this ~ ( C ~ H S C H Z N H ) ~ P4CsHsNHz S (4) case, however, a new triamide could form from the A second approach to the preparation of mixed excess amine present. Thus is it possible that thiophosphoric triamides appeared to be possible displacement reactions involving primary amthrough the reaction of dithiophosphoric dianilide ines and thiophosphoric triamides with primary with amines according to the equation amine residues attached to phosphorus be expressed as a mobile equilibrium (C6Hah”)zPSSH RNHz +
+
+
+
+
s
+
(CF,H~NH)ZP--(PU”R) HzS
(5)
This reaction has already been carried out with aniline to give thiophosphoric trianilide. When dithiophosphoric dianilide was treated with benzylamine, tribenzyl thiophosphoric amide rather than a mixed triamide was obtained. Tribenzylthiophosphoric amide must have resulted from the a Standard Oil Co.,Ohio, Fellow in Chemistry 1946-1947; present address, E. I. d u Pont d e Nemours and Co., Parlin, New Jersey. (1) Michaelis, Ann., 326, 129-258 (1903). (2) Buck, Bartleson and Lankelma, THISJOURNAL, 70, 744
(1948).
(RNH)aPS
+ 3R’NHz
