1974 2329Dimethylaminolysis of Dichlorophosphinothioyl CompoundsBy Gordon Bulloch, Rodney Keat,” and Norman H. Tennent, Department of Chemistry, University ofGlasgow, Glasgow G I 2 8QQThe reactions of [CI,(S)P],NR ( I ; R = Me or Ph) with dimethylamine have been investigated. When R = Me,mono-, non-geminal bis-, and tetrakis-dimethylamino-derivatives have been isolated, and the new ring compound(11). Me,N(S)b*NMe*P(S) NMe,.S, obtained by reaction with 6 mol dimethylamine heated under reflux in chloro-form solution. The analogous N-ethyl ring compound has been obtained from (I ; R = E t ) . Attempts to synthesisethe gerninal bis(dimethy1amino) derivatives, CI,(S) P*NR*P(S) (NMe,),, have been unsuccessful, although thereaction of CI,(S)P*NHPh with dimethylamine gives (Me,N),(S)P*NPh*P(S) (NMe,) (NHPh).Aminolysis ofC I , ( 0 ) P - N M e P ( S ) C I , by d i met h y I a m i n e , ( d i met h y I a m i no) t r i met h y I s i 1 a n e , a n d ( d i e t h y I am i n o ) t r i met h y I si I a n einitially occurs a t the phosphinothioyl centre in non-donor solvents, but in diethyl ether solution dimethylaminolysispreferentially occurs a t the phosphinoyl centre. Similar results have been obtained for CI,(O) P*N Ph.P(S) CI,.By contrast, dimethylaminolysis of the cyclodiphosphazane CI (0) P-NMe.P(S) CI.NBut occurs exclusively a t thephosphonoyl centre in donor and non-donor solvents. Non-gerninal bis- and tetrakis-dimethylamino-derivativesof CI,(O) P*NMe.P(S)CI, have also been isolated.-7I IDIMETHYLANINOLYSIS of halogenated compounds con-taining the P-N-P grouping has been studied 1*2 in somedetail during recent years.It is established that thecourse of replacement of chlorine atoms in (I; X = Y =0) bears certain similarities to that which occurs withR(I)hexachlorocyclo (tripliosphazene) , N3P,C1,, perhaps themost important of which is a non-geminal chlorine-atomreplacement scheme. Substrates of type (I) may alsobe expected to provide useful comparisons of the relativereactivity of phosphinoyl and phosphinothioyl groups tonucleophilic species, and with this in mind we undertooka study of diniethylaminolvsis of (I; X = 0 or S,Y = S).RESULTS AND DISCUSSIONBis(dichlorophosphinothioyl)methylamine, (I ; X =Y = S, R = Me) underwent ready reactions with di-methylamine in diethyl ether solution to give good yieldsof mono- and bis-dimethylamino-derivatives [equations(1) and (2)1.A41though Cl,(S)P*NPh*P(S)(Cl)NMe, was2NHMe,Cl,(S)P*N,Me-P(S) (Cl)NAie, +Me,H2NC1[Cl,( S) PI ,NMe-Me,N (Cl) (S) P-NMe-P (S) (Cl) -(2) NMe, + 2Me2H,NC1was obtained from (I; X = Y = S, R = Ph) in theI. Irvine arid 13. Keat, J.C.S. Dalton, 1972, 17.K. Keat, J.C.S. Dalton, 1974, 876.same way, it was necessary to heat under reflux in chloro-form to effect iormation of the bis(dimethy1aniino)derivative, Me2N(Cl) (S)P*NPh-P( S) (Cl) NMe,. The form-ation of non-geminal bis(dimethy1amino) derivatives as amixture of diastereoisomers was readily confirmed by theappearance of two 1 : 2 : 1 triplets in the lI-1 n.m.r. spec-trum of the AT-methyl compound and two singlets in lH-decoupled 31P n.m.r.spectra of the N-methyl and -phenylcompounds. The presence of diastereoisomers was alsoindicated by analytical-scale t .l.c., although meso- andm-forms were not distinguished. I t was hoped tosynthesise the isomeric geminal bis(dimethy1amino)derivatives by the route (3), but when R == hIe an(I\IIe,N),(S)P*NHR + P(S)Cl, -+adduct of triethylamine and t hiophosphoryl chloride wasobtained, and when R = Ph the synthesis of (Me,N),-(S)PNHPh proved impractical because of reaction (4).2CI,(S)P*NHPh + 7NHMe, --+(Me,N),(S) P.NPh*P( S) (KHPh) NMe, +EtsN(Me,N),(S)P*NR*P(S)Cl, -1- HC1 (3)4Me2H,NC1 (4)The condensation product formed was identified byelemental analysis, and lH and 31P n.1n.r.spectroscopy.A feature of the lH n.m.r. spectrum was the presence ofthree dimethylamino-proton doublets, two of which wereassignable to a (Me,N),(S)P group adjacent to an asym-metric (Me,N) (PhNH) (S)P centre. The spectrum wasonly slightly temperature and solvent dependent, incon-sistent with hindered rotation about the 1’-N bonds.R. Keat and 13. A. Shaw in ‘ Organic Phosphorus Com-pounds,’ eds. G. M. Kosolapoff and L. Maier, Wiley, New York,1973, vol. 6, p. 533.R. Keat, J.C.S. Dalton, 1972, 21892330 J.C.S. DaltonOther minor products were also obtained but not expected for diastereotopic -CH,- protons. Both cyclicidentified. compounds showed a complex set of dimethylamino-Attempts to synthesise tris(dimethy1amino) derivatives proton signals which formed the X part of an (AX,), spinof (I; X = Y = S) were also unsuccessful, although ~ y s t e m .~when R = Me the major products from the reaction with The tetrakis(dimethylamin0) derivative, (Me,N)(S)P*6 mol dimethylamine heated under reflux in chloroform NMe.P(S) (NMe,),, was readily obtained by reaction withsolution were the cyclic compound (11; R = Me), excess of dimethylamine heated under reflux in chloro-TABLE 1N.m.r. data a1H S l pr'- ~- ~ ,---A___-S(Nille) b,' 3J(P-N-C-H)/ 6(NMe,)/ 'J(P-N-C-H)/ S(31P) '/ 2J(P-N-PZH Z p.p.m. Hz p.p.m. Hz Compound p.p.m.CI,(O) P.NMe.P( S)C1, 3.46Cl,(O) P.NMe.P(S) (Cl)NMe, 3-21Me,N(CI) (0)P-NMe-P(S)Cl, 3.32Me,N (CI) (0) P-NMe-P( S) (CI) NMe, 3.10 (2)3.11 (1)(Me,N) ,(O)P-NMe*P( S) (NMe,) ,C1,( 0) P-NMe.P( S) (Cl)NEt,Cl,( 0) P*NPh.P(S)Cl,C1,(0) P-NPh*P(S) (CI)NMe, - C1( 0) P.NMe.P( S) CI-NBut3.202-90 (2)2.92 (1) - rtle,N( O)P.NMe-P(S)Cl.NBut 2.8(Me,N) ,(S)P.NHMe 2-63hle,N(S)P.NMe.P(S) NMe,.S 2.58Me,N(S)PNEt.P(S)NMe,*S ca.3-15 (CH,)(Me,N) ,(S) P*NPh.P(S) (NMe,)NHPh- r-2.81 [P(S)-(NMe,) (NHPh)l13-7 (PO),16-215.9 (PO),13.211.3 (PO),15.913.012.1 (PO),12.2 (PO),13.216.0 (PO),13.416.1 (PO),16-916-8 (PO),17.2e11.915.3e12.02.952.812.79 (PO),2.922.80 (PO),2.942.72 (PO),2.763.43 (CH,)14.112.9,13.3 (PO),14.6,13.3,14.29.5 (PO),10.8,0.416-40.5 d0 . 3 d1.65 0.7 -1.5 (PO),[ W u t 11 40(isomers) [(O)P-N-C-C-H] 43(both) ('J- - 2 (PO),ca. "-[ ( S ) P-N-C-C-HI)2.82 11.2 6.5 (PO),46.52.63 11.9 79.52.97 15-2 f 592-99 15.2 J 582.53 14.0, 75 [P(S)-1.0 d (NMe2)21, 602-43 14.2,0-8315.714.613.99.713.3303531.543-032.89.89.06.0All d a t a obtained from CH,Cl, solutions.b Figures in parentheses indicate isomer ratios. Relative t o 857; H3P0,.5J[(S)P-N-P-N-C-H]. e Not measured. f 3J(P-N-C-H) + J(P-N-P-N-C-H).Me,N(Cl) (S) P*NMe*P( S) (Cl)NMe,, and (Me,N),( S) P*NMe*P(S) (NMe,),. The reaction was repeatable whenMe2 N ( S 1 P<L>P (S lNMe2R(II 1R = Et, but not when R = Ph, which gave mainlyMe,N(Cl)(S)P*NPh*P(S)(Cl)NMe,. Only oEe of the twopossible geometrical isomers of (11) was apparentlyformed in each case.Evidence for formation of thecentrosymmetric trans-isomer (or less likely the cis-isomer without a plane of symmetry) of (11; R = Et)was, obtained from the 31P-decoupled lH n.m.r. spectrum.This showed two quartets in a 1 : 1 ratio, assignable toinner quarters of the AB part of an ABX, spin systemform solution. This derivative was used in an attemptto prepare the tris(dimethy1amino) derivative by heatingtogether bis- and tetrakis-dimethylamino-derivatives, amethod which proved successful in the preparation ofC1(Me,N)(0)P*NMe*P(O)(NMe,),,l but here the startingmaterials were recovered unchanged.methylamine, (I; X = 0, Y = S, R = Me), reactedwith dimet hylamine or (dimet hylamino) trimet hylsilanein chloroform, methylene chloride, or carbon tetra-chloride solution to give good yields of mono-, bis-, andtetrakis-dimethylamino-derivatives [Scheme 11.Thefact that aminolysis occurs initially at the phosphino-thioyl centre was unambiguously established from themultiplicity of lines associated with the low-field (phos-(Dichlorophosphinothioyl) (dichlorophosphinoyl) -R. K. Harris, Canad. J . Chem., 1964, 42, 22751974 2331phinothioyl) signal in the ,1P n.m.r. spectrum, and byzH(31P) double resonance which clearly established thatCl2(O)l3-NMe.P(S)C1, Cl,(O)P.NMe-P(S) (Cl)NMe,(i)(411Me,N( C1) (O)P.NMe.P.(S) (Cl) NMe,meso +- dl(ii)(Me,N) ,(O) P*NMe*P(S) (NMe,) ,SCHEME 1 ( 1 ) RNMe, (R = H or Me3Si); (ii), HNMe, andCHCI,the dimethylamino-proton doublet collapsed on irradi-ation at the higher 31P-decoupling frequency (lower field).Attempts to prepare the isomeric monodimethylamino-derivative by the reactions (5) and (6) were unsuccessful.EtxNFinally, a comparison was made of the results of di-methylaminolysis of (I; X = 0, Y = S) with that of thecyclodiphosphazane C1( 0) P*NMe-P( S) C1*NBut .6 In thiscase n.m.r.experiments showed that dimethylaminolysisoccurred exclusively at the phosphonoyl centre, ir-respective of whether the experiment was carried out inmethylene chloride or diethyl ether solution [equationThe ease with which the mono(dimethy1amino) deriva-tives, C1,( S) P*NR-P( S) (Cl) NMe,, were isolated contrastswith the difficulties experienced in obtaining puresamples of Cl,(O)P*N&Ie*P(O) (Cl)NMe, which was alwaysaccompanied by substantial proportions of startingmaterial and the bis(dimethy1amino) derivative. I t isdifficult to understand why steric effects should makesuch a difference and we are tempted to conclude thatI( 7 ) ~Me,N (Cl) (0) P*N HMe + P (S) C1, 2,-(5)+ Me,N (Cl) (0) P*NMe*P( S) C1, + HC1E t,N(6)Me,N (0) PC1, + MeHN (S) PCl,-\-The st art ing dime t h ylamino-derivatives were recoveredunchanged and unidentified adducts or condensationproducts were precipitated.The presence of a mixture of diastei-eoisomers showedagain that the dimethylamino-groups were non-geminaiin the bis(dimethy1amino) derivative. No tris(dimethy1-amino) derivative was identified.Preferential reactionsat the phosphinothioyl centre appear to be a generalfeature of this class of compound because Cl,(O) P*NMe*P(S)(Cl)NEt, and Cl,(O)P*NPh*P(S)(Cl)NMe, were ob-tained in a similar way using non-donor solvents.Theuse of diethyl ether, however, had a very marked effecton the course of the reaction of (I; X = 0, Y = S ,R = Me) with Me,NH. The relative molar proportions(3 : 2 : 1 : 3) of the products CI,(O)P*NMe-P(S)Cl,,Me,N (Cl) (0) P*NMe*P( S) Cl,, C1,( 0) P*NMe*P( S) (Cl)NMe,,and Me,N(Cl)(O)P=NMe*P(S) (Cl)NMe,, estimated by l Hn.m.r. spectroscopy, suggest that preferential reactionwith dimethylamine now occurs at the phosphinoylcentre. There seems little doubt that the small propor-tion of Cl,(O)P*NMe*P(S) (Cl)NMe, is not due to facileconversion to the bis(dimethy1amino) derivative, becausereaction of Cl,(O)P*NMe*P(S)Cl, with 3.6 mol dimethyl-amine in diethyl ether gave only this mono(dimethy1-amino) derivative and the bis(dimethy1amino) derivativein a 1 : 5 molar ratio.It was not possible to separate thecomponents of the mixture to obtain a pure sample ofMe,N(Cl) (O)P*NMe*P(S)Cl,, but comparisons of theresults of lH, 31P, and 1H(31P) n.m.r. experiments leftlittle doubt as to its identity. The same mixture of bis-(dimethylamino) derivative diastereoisomers was ob-tained with excess of dimethylamine in diethyl ether, but,as with ( I ; X = Y = S, R = Me), complete replacementof all the chlorine atoms was only achieved on heatingunder reflux in chloroform solution.electron density is transmitted more effectively from onephosphorus atom to the next in the >P(S)*NR*P(S)<system than in >P(O)-NR*P(O)<.An alternative explan-ation for this behaviour, that deactivation of the secondMeCl(0)PON\P(S)CI + 2Me2NH - “’ButMeButMe2N(0)P<i)P(S)C\ +Me2H2NC1 ( 7 1phosphorus atom to nucleophilic attack by an intra-molecular interaction, (111), is discounted on the basis ofthe ‘ hard-soft ’ nature of the phosphorus and sulphuratoms (see also below).Rcm)It is not surprising to find that dimethylaminolysis ofthe bis(dichlorophosphinothioy1)amines (I; X = Y = S)proceeds by a non-geminal reaction scheme. Thissuggests that, as in the case of the phosphinoyl analogues(I; X = Y = 0), the rate of replacement of the firstchlorine atom at each phosphorus is determined by anassociative process, as is common to most nucleophilicdisplacements at phosphorus(v) .7 A further similarityto the phosphinoyl analogues is apparent in the absenceof a tris (dimethylamino) derivative.G.Bulloch and R. Keat, unpublished work.R. F. Hudson, ‘ Structure and Mechanism in Organo-phosphorus Chemistry,’ Academic, London, 19652332The isolation of the ring compound (11) during attemptsto synthesise the tris(dimethy1amino) derivative is some-what surprising since P-S bond formation and cleavageevidently occurs. Although we have no evidence relat-ing to the mechanism of cyclisation, it is interesting tonote that formation of this ring system seems particularlyJ.C.S.DaltonThe observation that the compounds (I; X = 0,Y = S, R = Me or Ph) undergo preferential reactions atthe phosphinothioyl centre in non-donor solvents istotally unexpected since phosphoryl halides are generallymore readily aminolysed than thiophosphoryl halide^.^These findings, and the pronounced solvent dependenceTABLE 2Preparative detailsSubstrate(amount/mmol)Cl , (S) P-Nh1e.P (S) C1 , (30)(1 20)C1,( S)P-NMe*P( S)C1, (24)CI,(S)I’-NEt.P(S)Cl, (365)Cl,P(S)-NPh*P(S)Cl, (18)1 e,N) ,( S) P-NMe.P(S) -(’I(NVI %)2 (15)C1,( S) P-NHPh (43)C1,( S) P-NHMe (92)(Me,N),(S)P*NHMe (14)Cl2(0)P.NMe.P(S)C1, (10)C1,( 0) P*NPh-P( S) C1, ( 14)Cl,(O)P.NNIe*P(S)Cl, (11)(11)(15)(22)(20)Me,Pu’(Cl) (O)P*NHMc (35)Cl,(S)P.NHMe (18)C1( 0) P.NMe.P(S) C1-N ButI-- ---1(10)s u bscqu en tR eac t an t s Solvcnt treatmcnt(amount/mmol) V/cm3 0J”C (t/h)NHiLIc, (60) Et,O (250) -78 Stirred (1)(480) (500) -78 Stirred ( i )(excess) CHC1, (150) -78 licfluscd(24)(30) Et,0 (200) -78 Stirred ( 2 )!SO) CHCI, (200) -78 Kefluxcd ( 3 )(220) (150) -78 Refluxcd(111) (100) -78 Reflusctl(12)(15)Rle,N (Cl) (S)P*NiLle- (100) 25 RefluscdP(S)(CI)NMe, (15) (24)hTHMe, (excess) (200) -78 llcfluxetl ( 1 )(400)PSCl, (14),Et,N (15)NHMe, (21)Me,SiNEt, (1 1)NHMe, (28)( 2 2 )(61)(132)(200) - 78 Hefluxetl (4)(100) 25 Reflused (3)CH,CI, (250) - 78 Stirred (1)(100) 25 Reflused (1)(100) - 78 Stirred (1)Et30 (300) - 78 Stirred ( 1 )(250) - 78 Stirred (1)(250) -78 Stirred (2)CHCI, (200) -78 Refluxcd(15)(Excess)PSCI, (35),Et,N (35)Me,NP(O)CI, (18) C,H, (75) 20 nekukeci (3)Et,N (18)(200) -78 RefluxedEt,O (150) 0 Refluxed(10)f 0.5)NHMe, (21) Et,O or -78 Stirred (1)CH,CI,(100)X p .,O,/”CO,/”Cor b.p.,Products (yo) ( P /n1n1Hg.)Cl,(S)P-NhIe.P(S) (Cl) Nhle, (35) 7 2-7 3Me,N(Cl) (S)P-XMe-P(S) (Cl)NMc, (46) 49-50(Me2N) (S)I’-X3Ie*l’(S) (Xb‘le,) ” (40) 55-86Cl3(SIL’.Nl’h.1’~S)(Cl)~~1e,)~ ( 7 1 ) 84-85Mc,N( C1) (S) I’-SPh-P( S) (Cl) NJlc,(both diastereoisomcrs)1 19-1 2 0(64)(both cliastcreoisomers)~ - m,s(s) ~-XM~-P(S)NJI& (3) i:10--150I - 1 JIc,?r’(S)l’.NEt.P(S)NiCle,.S (2.5) 93-97k,9 (Cl) ( S ) P.N€’h.l’( S) (Cl) NJlY,(major procluc t)S o reaction(RIe,S) (S) P-XI’h-P(S) (S3I(~,)SIIPh 142-1 4379 - 80(50)E t 3x -P (S) c1, ?(51e,N) ,(S) PSHJIc (74)CI,(O)P.SMe*P(S) (Cl)Xhle, (68) 68 (0.05)(Sle,N),(S) P-NHhlc,CI,(O)P*?TRSe-P(S) (Cl)NEt, (72) 107 (0.05)C1,(0) P-XPh.P(S) (CI)NhIe,CI,( 0) P.NMe-P(S)Cl, [3],(not purified)hIe,N(CI) (0) P-NILlc-P(S)Cl, [2;,Cl,(O)PNiLIe.P(S) (Cl)NMe2 [ 11,Me,N(CI) (O)P-SMe.P(S) (C1)-NMe, [31CI,(O)P.NMe.P(S) (CI)N;CIc, [l],Me,N(Cl) (0) P*NR.Ic-P(S) (C1)-NMe, [5]RIe,N(CI) (O)P.YMe-P(S) (CI)NMe, 5-1-55.5 c(67) (both diastercoisomers)Me,N( C1) (0) P.NMe*P(S) (Cl)NMc,[I], (Me,N),(O)P-NMe*-(Me,N) ,( 0) P.NMe.P( S) (NRle,) (56) 1 15 (0.1)Me,N(Cl) (O)P*NHMe,Me,N-P( O)C1,, [Cl(S) P.NhIe],, =?P(S) (NMe,), PIEt,IS.P(S)Cl, ?I ~~~ 1Me,N(O) P.NMe.P(S) C1-NBut(not purified)Relative proportions are indicated in square brackets.Separated by t.1.c. [alumina plates, eluted with light petroleum (b.p.60-80 “C)]. C Major diastereoisomer ; separated b y fractional crystallisation from light petroleum.favoured because the closely related heterocycle of the reaction, lead us to believe that an intramolecularI associative effect is responsible for the enhanced reactivityMe(S)~’NSiMe,*p(S)Me.S was Obtained from of the phosphinothioyl centre as shown in (IV) withthe reaction of trimethvlsilvl azide with Me 6)-I I P-S*P( S) MeS.8 H. W. Roesky and M. Dietl, Angew. Chem. Internat. Edn.,0 E. Fluclr, Topics Phosphorus Chenz., 1967, 4, 332.1973, 12, 425.CI, ; ,CICL - P< ‘P- CI // xfl1974 2333X = 0, Y =I S, or X = S, Y = 0.The former inter-action is favoured since (Me,N),PO is known lo to forman adduct with thiophosphoryl chloride, [(Me,N),P*O=P(S)Cl,]Cl-, but there is no evidence (n.m.r.) for any reac-tion between (Me,N),PS and phosphoryl chloride atambient temperatures. An interaction (IV; X = 0,Y = S) would be favoured over an intermolecular inter-action on entropy grounds, and would increase the im-portance of heterolysis of the (S)P-C1 bond in the rate-determining step of the reaction. We further suggestthat in diethyl ether, a donor solvent, the importance ofintramolecular effects are diminished and more ' normal 'orders of reactivity are observed. Intramoleculareffects of this type will not be possible in the cyclodi-phosphazane C1( 0) P-NMe-P(S)C1*NBut, which is con-sistent with the fact that it undergoes reactions withdimethylamine at the phosphonoyl-centre in bothI-- 1structure of the tris(dimethy1amino) derivative, but noevidence for its presence in reaction mixtures was ob-tained.C I(XIN.m.r.data for the (phosphinothioyl) (phosphinoy1)-amines are given in Table 1 and analogous data for thebis(phosphinothioy1)amines will be published elsewhere.12EXPERIMENTALEthanol wasremoved from chloroform by contact with basic alumina.Phosphoryl chloride and thiophosphoryl chloride werepurified by distillation. Triethylamine was dried by distil-lation from sodium. Dimethylamine and Et,N.SiMe, wereSolvents were dried by conventional means.conlpoulltlCI,(S) P-NbIe.P(S) (CI)NMe,[bIe,N(Cl) (S) P],NMc[ (Mc,N) ,(S) P],N RileTABLE 3Found Calc.Analytical data @P A r- r 1 C H N C.1 title C H N C1 m/eb11.7 3.2 33.5 304 12.0 3.0 33.8 30418.8 4.8 313 19.1 4.8 31332.7 8-25 21.4 33 1 32-6 8.2 21-1 331Me,N(S) P-N;Lle-P( S) NMc,*S 22.1 5-5 15.5 35.1 275 21.8 5-5 15.3 34.YC 276Me,N( S) P-NEt.P( S) NMe,.SC1 , (S) P*N Ph-l'( S) (CI) NMe,[Me,N (Cl) (S) P ] ,NPh(Me,N) (S) P.NPh-P( S) (NMe,) NHPhCl,(O) .P.NMe.P( S) (Cl) NMe,Me,N(Cl) (0) P*NMe.P( S) (Cl) Nhle,(Me,N) ,(O) P.NMe.P( S) (NMe,) ,Cl,(O)P-NMe*P(S) (Cl)NEt,25-2 5.8 14-95 28926-35 3.15 7.8 29-05 36632.0 4-55 18.7 39349.0 6.5 16.1 13-gd 44112.5 3.2 9.520-0 5.1 14.2 29732.9 8.5 20.5 31520.0 4.1 8.5 32.3 31624.926.1531.948.9512.420.1534.318.95.9 14-5 2893.0 7.6 28.9 3664-55 18.85 3936.6 15.9 14.0d 4413-1 9-75.1 14.1 2978.6 22.2 3154.1 8.8 33.5 316C1( 0) P-NMe*P( S)C1.NBut 20.8 4.7 8.7 280 21-4 4.3 10.0 280(Me,N) ,(S) PNHMc 33-3 8-95 23.05 181 33.15 8-9 23-2 181IMe,N(O) P*Nhle.€'(S) C1-NBut 289 289(1 Elemental analyses figures are given in 9;.b For ions containing 35Cl. e S analysis. d P analysis.met hylene chloride and diethyl ether solutions. Nucleo-philic displacements at phosphorus(v) in four-memberedrings generally take place with retention of configur-ation.ll This may be the case here, but we have noreason to believe that formation of the expected tri-gonal-bipyramidal intermediate and any subsequentpseudo-rotation step will invalidate the conclusion that,in general, the phosphonoyl centre is more reactive thanthe phosphonothioyl centre to dimethylamine.The formation of a bis(dimethy1amino) derivative,Me,N(Cl) (O)P*NMe*P(S) (Cl)NMe,, is anticipated in termsof the reduced electrophilic nature of the phosphino-thioyl centre in non-donor solvents.An interaction ofthe type (V) might be possible even in diethyl ether solu-tion, and may, in part, be responsible for the relative easewith which the bis(dimet1iylamino) derivative is formedin this solvent. It would also be instructive to know thelo H. Binder and E. Fluck, Z . anorg. Chem., 1969, 365, 170.l1 J. R. Corfield, R. K. Oram, D. J. H. Smith, and S. Trippett,l2 G. Hagele, R. K. Harris, M. I. M. Wazeer, and R. Keat,J.C.S. Perkin I , 1972, 713.J.C.S. Dalton, in the press.obtained commercially and used without further purific-ation. The compounds Me,N-SiMe3,13 C1,(0) P*NMe,,l4CI,(S) P*NHMe,4 Cl,(S) P.NHP1i,4 [Cl,(S) P],NMe,4 [Cl,(S) PI2-NEt,4 C1,(0)P-NMe-P(S)C1,,4 C12(0)P.NPh-P(S)C.I,,4 andC1(0)P*NMe-P(S)C1]NBut were prepared by literaturemethods.1H and 31P N.ni.r. spectra were recorded on a Jeol C60HLspectrometer and selective-noise 31P and lH decouplingcarried out with a Schomandl ND lOOM frequency synthesiserand a Jeol SDHC unit. Aminolysis reactions were carriedout as previously described 1 9 , and details are given inTable 2. Analytical data are given in Table 3 and n.m.r.data in Table 1.-We thank Dr. W. McFarlane for some 1H.[31P) n.m.r.measurements and the S.R.C. for the award of a researchstudentship (to G. B.) and funds for n.m.r. equipment.[4/955 Received, 16th May, 19741R. A. Pike and R. L. Shank, J . Org. Chem., 1962,27, 2190.I4 E. Fluck and W. Haubold in ' Organic Phosphorus Com-pounds,' eds. G. M. Kosolapoff and L. Maier, Wiley, New York,1973, vol. 6, p. 579