NOTES
Feb. 20, 1955
907
lium,l0 silicon,ll tin,llal* lead,l1*J* p h o s p h o r u ~ , ~ ~ J ~ arsenic, 14. 16-l7 antimony 4, l6 and bismuth. We found that treatment of germanium tetrachloride with one equivalent of diazomethane in ether solution a t -GO to -70” in the presence of copper powder gave a 93.7y0 yield of chloromethylgermanium trichloride. Higher boiling residues from three preparations of approximately 0.1 mole each were combined and fractionated t o give 5.5 g. COLLEGE OF CHEMISTRY AND PHYSICS of bis-(chloromethy1)-germanium dichloride. SimiSTATE UNIVERSITY THEPENNSYLVANIA STATECOLLEGE, PENNA. larly, the reaction of diazomethane with methylgermanium trichloride gave chloromethylmethylgermanium dichloride in 78% yield. Treatment of The Preparation of Chloromethyl Derivatives of CHSGeCla with a slight excess of diazomethane Germanium and Silicon by the Diazomethane over that required for introduction of two methylene groups under the same conditions resulted in a Method 20.5% yield of methyl-bis-(chloromethy1)-germaBY DIETMAR SEYFERTH’ AND EUGENEG.ROCHOW nium chloride and a 33.5% yield of the mono-(chloromethyl) derivative. However, no methylenated RECEIVED AUGUST19, 1954 product was obtained from the reaction of dimethThis paper reports the application of the reaction ylgermanium dichloride with diazomethane a t -GO of diazomethane with germanium and silicon halides or a t 0’. (or their organic derivatives) to the preparation of Under similar conditions the reaction with silichloromethyl compounds of these two elements. con tetrachloride gave chloromethyltrichlorosilane It is shown that the reaction proceeds more readily in only 45-4770 yield, while treatment of methyltriwith the halides of germanium than with those of chlorosilane with diazomethane resulted in a 13% silicon, permitting yields as high as %yoof theoret- yield of chloromethylmethyldichlorosilane. llb ical for germanium (in the preparation of chloroWe have found that trichlorosilane, HSiCls, remethylgermanium trichloride) and 73% for silicon acts readily with diazomethane in ether solution at (in the preparation of chloromethyldichlorosilane) . -GO to -70” in the presence of copper powder to Other methods for the same purpose are available. give a 73.3% yield of chloromethyldichlorosilane, a Side-chain chlorination of tetramethylsilane12 of heavy, colorless liquid that fumes strongly in air. methylchlorosilaness-6 and of methyl~iloxanes~ can Trimethylchlorosilane, triphenylchlorosilane and be accomplished by treatment with chlorine under tetraethoxysilane do not react with diazomethane the influence of ultraviolet light or by reaction with a t -GOo or a t 0”. Only the unreacted silanes, tosulfuryl chloride in the presence of a peroxide cata- gether with small amounts of their hydrolysis prodlyst. However, similar reactions have not been ucts, were recovered. reported for any methylgermanium compounds. Chloromethyltrimethylgermane, chloromethyldiThese methods cannot be applied to the preparamethylsilane and chloromethyldiethylsilane were tion of chloromethyl derivatives of silanes containing an SI-H bond, since either reagent would prepared by the reaction of the chloromethyl derivacause chlorination of that bond as well. Even when tives obtained by the diazomethane method with they do apply, chlorinations give only moderate the appropriate Grignard reagent. The fully alkylyields of mono- (chloromethyl) derivatives, and so ated products were obtained from Grignard derivait seemed desirable also t o prepare our chloromethyl tives in about 90% yield. The preparation of chloromethyltrimethylgerderivatives of germanium by a more efficient mane is of importance because this compound may method. Hellerman and Newmans first described a novel serve as an intermediate for the study of the as yet method for the preparation of halomethyl deriva- unexplored field of organofunctional germanium tives of mercury: the reaction of diazomethane chemistry. The preparation of chloromethyltriwith a mercuric halide in ether solution methylsilane and other halomethyl derivatives of silicon similarly was instrumental in making the HgClz CHiNz ----f CIHgCHzCI Nz
changes in the conductance-viscosity product alone are not reliable as indicating changes in the degree of dissociation of a salt. The equations of Wishau and Stokes cannot account for an increase in the conductance-viscosity product and some significant change in the theory must be introduced before the behavior of salts a t extremely high concentrations is understood.
+
+
More recently Yakubovich and his co-workers have extended this “ m e t h y l e n a t i ~ n ”reaction ~ to the preparation of a-haloalkyl derivatives of thal(1) Charles Lathrop Parsons Scholar, 1963-1964. (2) F. C. Whitmore and L. H. Sornmer, THISJOURNAL, 68, 483 (1946). (3) R. H. Krieble and J. R. Elliott, ibid., 67, 1810 (1946). (4) G. F. Roedel, ibid., 71, 269 (1949). (6) F. Runge and W. Zimrnermann, Bcr., 87, 282 (1964). (6) J. J. McBride and H. C. Beachell, TBIS JOURNAL, 70, 2632
(1948).
(7) R. H. Krieble and J. R. Elliott, ibid., 68, 2291 (1946). ( 8 ) L. Hellerman and M. D. Newman, ibid., 64, 2859 (1932). (9) By “methylenation” is meant the introduction of the -CHIgroup, just as methylation indicates the introduction of the -CHI group.
147
(10) A. Ya. Yakubovich and V. A. Ginsburg, Doklady A k a d . N a u k S.S.S.R., 7 3 , 957 (1950); C. A . , 4 6 , 2867 (1951). (11) (a) A. Ya. Yakubovich, S. P. Makarov, V. A. Ginsburg, G. I. Gavrilov and E. N. Merkulova, ibid., 74, 69 (1950); C. A . , 46, 2868 (1951); (b) A. Ya. Yakubovich and V. A. Ginsburg, J . Gcn. Chcm. (U.S.S.R.), 2 2 , 1783 (1952); C. A , , 47, 9256 (1953). (12) A. Ya. Yakubovich, S. P. Makarov and G. I. Gavrilov, ibid., 22, 1788 (1952); C. A , , 47, 9257 (1963). (13) A. Ya. Yakubovich, E. N. Merkulova. S. P. Makarov and G. I. Gavrilov, ibid., 22, 2060 (1952); C. A . , 47, 9257 (1953). (14) A. Ya. Yakubovich, V. A. Ginsburg and S. P. Makarov, Dok. l a d y A k a d . N a u k S.S.S.R., 71, 303 (1950); C. A., 44, 8320 (1950). (15) A. Ya. Yakubovich and V. A. Ginsburg, J . Gcn. Chem. (U.S.S.R.), 22, 1534 (1962); C. A , . 47, 9254 (1953). (16) A. Ya. Yakubovich and S. P. Makarov, J . Ccn. Chrm. (u.s.s.R.) 21, 1628 (1952); c. A . , 47,8010 (19.53). (17) G. I. Braz and A.Ya.Yakubovich.J.Gen. Ch6m. (U.S.S.R.) 11, 41 (1941); C. A., 86, 6469 (1941).
908
Vol. 77
NOTES TABLE I CHLOKOMETHYL DERIVATIVES OF GERMANIUM AND SILICOX 0 5 4
93.7
..
~ZOD,ref. 5.
*
78 20 5 79.8 60 73.3 59 55 d*Opo, ref.
60-65 90 71-74 95-97 113-114 111-112 97-97.5 80-81 135-138 llb.
35 21 40 30 761.5 768.6 773 763 760
1.4989 1.5176 1.4890 1.5010 1.4389 1 ,4450" 1.4150 1.4357
1.833 1.642 1 189
Carbon Calcd. Found
Analyses, % ' Hydrogen Calcd. Found
5.26 9 91 11.55 16.2 28.71
5 58 10 16 11.66 15 4 28 A4
0.88 1.66 2.42 3.18 6.64
1.03 1.56 2.23 3.07 G.C5
8 03 33.2 43.94
8 14 33 31 43 62
2.02 8.35 9.58
2.11 8.14 9.51
Calcd. Chlorine Found
62.08 58.49 51.13
62.10 58.26 51.56
21.21
20.7.5
71.17
7l.jl
1 4776b
0.888
Methylenation of Trichlorosi1ane.-The identical procestudy of aliphatic organofunctional silicon chemisdure was used in the methylenation of 40 g. (0.296 mole) of try possible. trichlorosilane in 100 ml. of anhydrous ether with 0.194 mole Incidental to this work on the preparation of of diazomethane in 350 ml. of ether. A 73.3% yield of chloromethyl derivatives of germanium and silicon chloromethyldichlorosilane was obtained. A 60% yield of chlorotnethyltrichlorosilane was obit was found that dimethyl-his- (chloromethy1)-sitained in the methylenation of silicon tetrachloride when lane forms a dilithium derivative, (CHZ)$i(CHtLi)2. this procedure was used. Yakubovich and Ginsburg1Ib Only one report of dilithioalkanes has appeared18 had previously reported yields of 4 5 4 7 % . This proand no dilithium or di-Grignard reagent of a bis- cedure was also fol1o;ved in the attempted methylenation (haloalky1)-silane has been reported. Treatment of of trimethylchlorosilane, triphenylchlorosilane and tetradimethyl-bis-(lithiomethyl)-silane with trimethyl- ethoxysilane. Chloromethyltrimethylgermane.-To three moles of CHIchlorosilane gave 2,2,4,4,6,6-hexarnethyl-2,4,6-triMgBr in one liter of anhydrous ether there was added 58.8 g. silaheptane in 36.5y0yield. This silicon-containing (0.258 mole) of chloromethylgermanium trichloride and dilithium reagent has many possibilities for inter- 24.3 g. (0.1 16 mole) of chloromethylmethylgermanium dichloride (diluted with an equal volume of ether) at such a esting preparative work. rate that a moderate reflux was maintained. After the addition was completed the reaction mixture was refluxed for 14 hours, cooled t o O " , and 400 ml. of saturated NHiCl solution was added. The organic layer was separated from Diazomethane was prepared from n i t r o s ~ m e t h y l u r e aby ~ ~ the precipitated salts, which were then dissolved in dilute the method of Bachmann and Struve.20 The yield of diazohydrochloric acid, leaving a small organic layer that was methane was determined by treatment of a 10-ml. aliquot added to the previous one. After drying and removal of of its ethereal solution with a solution of excess of benzoic the ether, fractionation yielded 49.7 g. of chloromethyltriacid in ether and titration of the excess acid with a standard methylgermane. solution of alcoholic potassium hydroxide. The diazomethChloromethvldimethvlsilane and chloromethyldiethylsiane solutions were dried a t -50" over potassium hydroxide lane were prepared using procedures identical with that depellets. scribed above. Methylenation of Germanium Tetrachloride .-A solution The yields, physical constants and analyses of these new of 28.0 g. (0.12 mole) of germanium tetrachloride in 130 chloromethpl derivatives of germanium and silicon are listed ml. of anhydrous ether in a one-liter, three-necked flask in Table I. The analyses were performed by Dr. S. M . equipped with a mechanical stirrer, a Y-joint holding a penNagy and his associates, Microchemical Laboratory, Massdtane thermometer and a drying tube, and a 500-ml. dropping chusetts Institute of Technology. funnel, was cooled to -60" and about 0.5 g. of copper powDimethyl-bis-(lithiomethy1)-silane and its Reaction with der was added. A cold solution of 0.128 mole of diazometh- (CHa)sSiCI.-The procedure described in ref. 18 was ane in 250 ml. of ether was then added slowly with vigorous followed. The dilithium reagent was prepared from 5 g. stirring. Nitrogen evolution began immediately. After 10.7 g. atom) of Li shot and 20.4 g. (0.13 mole) of (CHihthe addition was completed the reaction mixture was stirred Si(CH2C1)2 in 200 ml. of anhydrous ether. After addition a t -60 to -70" for tn-o hours under an atmosphere of dry of the silane was completed the reaction mixture gave a nitrogen and subsequently was allowed to warm up to room positive Color Test I , 2 * Trimethylchlorospne, 56.5 g. temperature. Stirring was continued a t room temperature (0.52 mole), mas then added a t -15 to -20 . Hydrolysis for two hours. After distillation of the ether through a 12- of the reaction mixture with subsequent drying of the organic inch Vigreux column the residue was transferred to a small layer and fractionation gave 11.0 g. of [( CH?)ISiCH?lpSidistillation unit equipped with a 6-inch vacuum-jacketed CHI)^, b.p. 69-71 a t 7 mm., n 2 5 ~1.4391, dZ540.7961, a column packed with glass helices. Fractionation yielded 7.2 yield of 36.5%, and 6 g. of material boiling over a wide g. of unreacted GeC14and 20.8 g. of C1CH2GeCl3,a yield of range, 120-150' at 4 nun. and above. 93.7% based on the unrecovered germanium tetrachloride. Anal. Calcd. for C10Hz8Si3:C, 51.65; H , 12.14. Found: The higher boiling residues of this and two other preparations of similar size were combined and fractionated t o C, 51.02; H, 12.09. yield 5.5 g. of (CICH2)2GeCI2. Acknowledgments.-The authors are indebted to An identical procedure was used to methylenate methyl- the Linde Air Products Company for the trichlorogermanium trichloride and in the attempted methylenation silane used in this work, to the Research Laboraof dimethylgermanium dichloride. 21 Experimental
(18) R. West and E. G. Rochow, J. Org. Chem., 18, 1739 (1953). (19) F. Arndt in "Organic Syntheses," Coll. Vol. 11, John Wiley and Sons, Inc., New York, N.Y.,1943,p. 461. (20) W. E. Bachmann and W. S. Struve, Org. Reactions, 1, 50 (1942). (21) The methylgermanium chlorides were obtained by the direct reaction of methyl chloride with powdered germanium using copper as a catalyst; cf. E. G. Rochow, THISJOURNAL, BB, 1729 (1947).
tory, General Electric Company, for the dimethylbis-(chloromethy1)-silane,and to the Mallinckrodt Chemical Works for financial assistance.
DEPARTMENT OF CHEMISTRY HARVARD UNIVERSITY CAMBRIDGE 38, MASSACHUSETTS (22) H.Gilman and F. Schulze. ibid., 47, 2002 (1925).
