an isocyanide stretching f r e q u e i ~ c y . ~R strong broad band with maximum absorption a t 728 cm. -', considerably displaced from the Sic1 band at 800 cm.-' for Sic14 and a t 810 cm.-l for HSiCla, is undoubtedly the Sic1 band since it is the only other major band in the spectrum. A more detailed study of the spectrum for this (8) L . F. Leloir, C. E. Cardini and J. hl. Olsoarria, Arch. Biochem. compound is indicated before one can draw any Bioghys., 74, 84 (1968). well-founded conclusions concerning its structure. DEPARTMEXT O F MEDICAL MICROBIOLOGY, UNIVERSITY However, the features so far observed are compatOF SOUTHERN CALIFORSIA SCHOOL OF MEDICISE Los ANGELES,CALIFORNIA, AND L. I. HOCHSTPIN ible with either a very rapid cyanide-isocyanide 1. B. ~ V O L F E SCRIPPS CLINICAND RESEARCH FOITNDATION LA JOLLA, CALIFORNIA ~ iI.. N A K A D A equilibrium3 greatly favoring the cyanide form, or a cyanide model with asymmetry introduced by backRECEIVED J U N E 3 , 195% bonding involving the 3d orbitals of the silicon. This explanation could also account for the shift of the Sic1 band to longer wave lengths. PREPARATION AND SOME PROPERTIES OF TRICHLOROCYANOSILANE' An unsuccessful attempt to prepare SiClnCN Sir: has been reported4; Goubeau and Reyhing exam'l'reatnient of mercury(I1) cyanide with disilicon ined several metathetic reactions involvilig various hexachloride liquid or vapor a t approximately tetravalent silicon halides and differelit group I 100" results in a volatile, colorless liquid, melting cyanides. On the basis of the failure of this prrpoint -46.2 + 0.2", which can be separated from vious attempt and the conditions of the prcscnt unchanged disilicon hexachloride by distillation preparation, a mechanism involving addition of in z'acuo through traps maintained a t -63 and cyanyl radical to the silicon-silicon bond is sug-78'. The -63" trap retains unchanged di- gested. Further investigations of the chemical properties silicon hexachloride, identified by its - 1' melting point. The -78" trap retains the colorless liquid of the new compound and its derivatives are i n progress. which exhibits these vapor pressures :
corresponding N-acetylhexosaminic acids, thus differing from previously reported mechanisms for the metabolism of N-acetylhexosamines.8 The purified enzyme preparation did not catalyze the disappearance of glucosamine, galactosamine or glucose.
1, 'C.
P,, (obs.) P,,(calcd.)
-45.2
2.3 2.25
-30.7
6.2 6.24
-22.9
10.0 10.3
00.0
10
20
37.6 37.8
62.2 62.1
101.6 99.3
The calculated values are obtained from the equation log P,, = i . 7 5 1 - ( 1 6 8 i / T ) from which a AfTvap of '7,720 calories per niolc and an extrapolated boiling point of 73.2" can be calculated. Thus the Trouton constant for this liquid is 22.2. The formula SiClaCh' was established for this compound by analysis corresponding to the formula Sil.opC12.98(CN)o.s6 and by the vapor density measurement a t 2'7.8" corresponding to an apparent molecular weight of 158.8; calculated for SiC13CN, 160.4. The new compound is stable indefinitely a t -78" in vacuo and in the vapor phase a t room temperature. I n the liquid phase at room temperature the compound undergoes a slow decomposition, producing silicon tetrachloride and nnnvolatile brown solids. Trichlorocyanosilane undergoes rapid hj-drolysis. n'ith limited aniounts of water vapor hydrogen cyanide and hexachlorosiloxane result. The water solution from complete hydrolysis gives a strong Turnbull's Blue test for CN-. The infrared absorption spcctruiii of tlic vapor shows a strong sharp peak a t 2200 cni.-l characteristic of C N stretching2n3and a moderately strong sharp peak at 2080 cm.-', previously assigned as (1) T h e authors wish gratefully t o acknowledge t h e partial support of this work b y t h e Research Corporation under a Frederick Gardner Cottrell G r a n t . (2) H. R . Linton a n d E. R . Xixon, Speclrochim. Acln, 10, 299 (19.58). (3) T . A. Bither, W. H . K n o t h , R . V. Lindsay, Jr.. and U'. €1. Sharkey, THIS J O U R N A L , 80, 4151 (1968).
(4) J. Goubeau a n d J. Reyhing, 2. anorg. u . o i l g e m . C h e m . , 294, 96 (1958).
DEPARTMEST OF CHEMISTRY PURDUE USIVERSITY ALEXANDERKACZMARCZYK LAFAYETTE, INDIAXA GRAST UKRV RECEIVED JUNE 10, 1959
SIMPLE
SYNTHESES OF PYRIMIDINE-Z'-DEOXYRIBONUCLEOSIDES'
Sir : Recent studies with 5-fluoro-2'-clcoxyuridinc (P-FUDR) and j-fluoro-Z'-deoxycytidine (P-FCDK) have demonstrated their usefulness as anti-tumor agents in several experimental tumors2f3and in clinical trial^.^ P-FUDR was prepared5 by enzymic procedures while P-FCDR was synthesized6 from P-FUDR. I n view of the need for Fi-fluorinated-2'-deoxynucleosides, we report the total syntheses of pyrimidine-2'deoxyribonucleosides by the mercuri p r o c e d ~ r e . ~It~ was ~ found that crys(1) T h i s investigation was supported in p a r t ( t o t h e Sloan-Ketterinp Institute) b y f u n d s from t h e National Cancer Institute a n d t h e National I n s t i t u t e s of Health, Public Health Service (Grant No. CY3190). (2) C . Heidelberger, L. Griesbach, 0 C r u z , R . J . Srhnitzer a n d E
