GLENND. COOPERAND ALFREDR. GILBERT
5042
cury with an immersed capillary t o serve as a manometer. The remaining air was displaced by mercury. The tube was heated a t 49' for about 20 hr. The rising Hg in the long capillary indicated a pressure of about 2 atm. Then the reaction mixture was cooled t o O0, transferred into a beaker and immediately treated with an excess of 3 N HC1 t o dissolve the resulting N(CH3)3 and the unused reactants. The oil was shaken with dilute HC1 several times, washed with water, separated and dried with anhydrous Na2C03. A small amount of niateridl was recovered from the aqueous layers by extracting with hexane. I n a number of experiments yields in the range of 50 to 56% of ( ~ S O - C ~ H ~ O ) ~were P B Hobtained, J the average being 53%. Reactivity of Trialkyl Phosphite Borines Toward I?. Method.--il weighed amount of the substance was dissolved in 2 ml. of CHIOH and added to aomixture of 50 ml. of 0.1 N IZand 100 ml. of CH,OH a t 23 , After 70 hr. the unreacted IZ was titrated with 0.1 N arsenite solution in the presence of NaHCOa. The Ip consumed is calculated in niilliequivalents and shown in the table below. The last column contains the number of equivalents of I? consumed per mole of substance. According t o the equation (R0)3PBHa 412 4H2O .= &Bod 8HI OP(OR)J one mole of trialkyl phosphite borine should consume 8 equivalents of 11.
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was subtracted from the amount of 0.1 N IZ consumed in the tests. (R0)sPBHs
Mmoles used
Meq. I? consumed
Eq. 1% consumed per mole substance
R = CH3 R = CzHb R = iso-C3H7
1.05 1.30 0.02
0.32 0.86 1.23
0.31 0.66 1.34
The results show that the numbers of equivalents of IZ consumed per mole of substance are smaller than in the previous experiments (in the absence of pyridine). However, the ratio of the reactivities of (CH~O)BPBHB, (C?H50)3PBHB arid (iso-CaH;O)aPBH3 is 1:2.13:4.3 which is close to the previous results found in the absence of pyridine. Proof of the Constitution of (RO)3PBH3,(CsHj0)3PBK) P[N(CHs),], + [(CHI)~X]~PB 4-HP(OC&)Z ~ (a) A mixture of 2.4 g. of (CoH50)3PRH3 and 3.6 g. of P[X(CHO):!]~ was heated a t 100' for 30 minutes. The reaction mixture was steam distilled. The distillate was acidified with HC1, the crystalline product filtered, washed with H20 and dried in air to a constant weight, producing 0.985 g: = 75.0y0 of [(CH3)2Sl3PBHa;m.p. 32:O". The constituEq. 1 2 has been established.2 tion of [(CH~)ZN]SPBH; Substance consumed 1 2 consumed, per mole used, (~so-OC~H~)~PB P[S(CH3)2 H~ 13 + HaBP(0R)r "ole meq. substance [(CHahNhPBHa (iso-C3HiOhP (b) R = CHs 0.71 0.35 0.49 A mixture of 2.22 g. of ( ~ S O - C ~ H , O ) ~ Pand B H 4.89 ~ g. of R = CIHS 0.92 1.11 1.20 P[x(CH3)2]3 was heated a t 110" for 45 minutes. The R = iso-CaHi 0.66 1.61 2.45 reaction mixture was worked up as in the foregoing experiH~, Because of a possible side reaction, the results obtained may ment; obtained 1.25 g. of [ I C H ~ ) Z S ] ~ P B70.5%. not represent the actual extent of the over-all reaction. ( C H Z O ) ~ P B H ~( ~ S ~ - C ~ F I ~---f C))~P However, qualitatively these attempts indicate that the (iso-C~H,0)3PBH3 P(OCH3)s f (c) order of reactivity of the trialkyl phosphite borines toward A . mixture of 13.78 g. of ( C H 3 0 ) D P B Hand ~ 40.0 g. of (isoI 2 1s C3H7)aPwas subjected t o distillation a t atmospheric pres(CH30)3PBH3 < ( C Z H ~ O ) ~ P B
