Nucleosides from Homoribose' JOHN
Yc1rE:als
1
8.RIOXTGOMSRY A?*D ~e described the *:,ntlie-is of iiomoribose and hornw .di~nosinebv a different route I a) I< J R s a n , €I 1r/oomanian I 11 \r t o n , anti I, (Tooiiman, J Am Chem Soc , 8 6 , 2507 (1961) ('1) €1 Zinner, BET 83 1 5 3 (1Y50) 8 6 , 81; (1'3533 ( 6 ) i K . 1, Rinehart, Jr \\ 3 C h i t o n , AI H I ( tieris and \\ \ o n €'Inhp\I m Chem S o c , 8 4 , 3216 (19b2) Paro T dhimadatr and Y Islii(iii i'c1,pi~n Kcindic Zn 11)
rliis
1 I I P Lancer Chemotherapy q t itiite, Kational Institutes
(lCIl,O~
CHLOH I1
CH,COO TI I ('I
OOCCH,
NOTES
l'tarch 1966
236 TMS
I
8.0
. .
I
.
I
7.0
. . .
I
I
6.0
.
I . . . .
I
. . . I .
. I _ .
4.0
5.0
l . . . . l . . . . l . .
3.0
I .
2.0
. ,
I .
1.0
.
I
0
7 ( p . p. m.)
Figure l.-Proton
magnetic resonance spectra of 9-(2,3,5-tri-0-acetyl-~-~-r~bofuranosyl)-2,6-d~chlorop~~ri~~e (top) and VI11 (bottom).
deoxy-~-~-ribohexofuranosyl)-6-chloropur~ne (IX) as istic (4.0-4.2 ppm) and the coupling constant J 1 1 2 f to a glass. This material was deacetylated in the usual lie between 5.1 and 5.7 cps. I n the present work the manner to give 9-(5-deoxy-~-~-ribo-hexofuranosyl)-6values for the deacetylated nucleosides derived from chloropurine (VI), also obtained as a glass. Reaction VI11 and IX fall in these ranges (see Experimental of VI with sodium hydrosulfide in methanol gave Section). 9-(5-deoxy-p-~-ribo-hexofuranosyl) purine-6 (1H) - thione Treatment of VI11 with methanolic ammonia a t 5' (VII), a homolog of 6-mercaptopurine ribonucleoside. for 1 week resulted in removal of the acetyl groups Biological Activity.-The toxicity of NB, HEpfrom the sugar hydroxyls with concomitant displace2/S, and HEp-2/RiIP cells in culture of the homoriboment of the chlorine atom at C-6 of the purine moiety, nucleosides, 2-chlorohomoadenosine (IV) and 6-merbut in contrast to the results obtained with 9-(2,3,5tr~-0-acetyl-~-~-ribofuranosyl)-2,6-d~ch~oropur~ne,~ the product was a mixture of 2-chloro-9- (5-deoxy-P-DTABLE I __ EDso" ribo-hexofuranosy1)adenine (2-chlorohomoadenosine, HEpIV) and 2-chloro-6-methoxy-9-(5-deoxy-~-~-ribo-hexoCompd KB HEp-P/S 2/MP furanosy1)purine (V). The identity of V was firmly 2-Chloroadenine 11 established from its ultraviolet, infrared, and proton IV >lo0 >100 100 magnetic resonance spectra. The potent nucleophili6-Mer cap topurine 0.25 0.25 >loo city of the methoxide ion has been observed before.I4 VI1 3.1 2.8 >lo0 Reaction of I11 with 6-chloropurine as described a EDGOis that concentration of compound in pg/ml inhibiting above gave a 46% yield of 9-(2,3,6-tri-O-acety1-5- the growth of cells to 50% of controls. Cells were grown on glass
-
(14) J. A. Montgomery and C. Temple, Jr., d . A m . Chem. S o c . , 83,630 (1961).
and growth was measured by determination of protein content [V. I. Oyama and H. Eagle, Proc. SOC.Ezptl. Biol. Med., 91, 305 (1956)] after 4 days growth in the presence of the compound.
March 1Wti
237
SOTES
SCHEME I Norit, and evaporated to dryness to give a yellow oil which redissolved in warm ethanol. The crystals that formed were collected by filtration, washed with ethanol, and dried in z'aczio to give essentially pure product, yield 950 mg (34%), mp 121". Thin layer chromatography on silica gel H (Nerck) using CHC13-ethyl acetate (4: 1) as the eluent showed 2,6-dichloropurine as the only contaminant. Recrystallization of a sample V, R = CH3; 11' H I, X = CHzOH of the isolated material from boiling ethanol gave the pure prod\T, 11 = H: 11' = CHO 11. S = CH=O uct: nip 123'; A, [in mp ( € X p H 1, 7-222 (7.31, 111: F = CH=CHNO, 11-,X = CHzCHzNHz 273 (13.2), 280 (sh), pH 13-255 (sh), 258 (15.0), 265 (sh), 280 (sh); ; ,,, (in cm-l), 3115, 3060, 3050-3000 ( C H ) , l i 5 5 , 1740, 1725 (C=O), 1595, 1560 (C=C, C=S), 1240, 1205 (COC). Anal. Calcd for C17Hl8Cl2N4O7: C, 44.37; H, 3.94; iY,12.18. Found: C, 44.25; H , 3.99; N, 12.12. 6-Chloro-S-(2,3,6-tri-0-acetyl-5-deoxy-~-~-ribo-hexofuranosy1)purine (IX).-.4 mixture of 6-chloropurine (1.5 g, 9.7 rnmoles) and 1 , 2 , 3 , 6 - t e t r a - 0 - a c e t y l - 5 - d e o s y - ~ - ~ - r i b o ose (111, 3.4 g, 10.0 mmoles) was fused 2'n vacuo ( 2 5 nini) a t 130" with p-toluenesulfonic acid cat,alyst ( 7 5 mg) for 25 min. The XII, R = CH3 XIII, R = H resulting dark melt was cooled to room temperature, dissolved in XIS, R C& CHC13 (10 ml), and filtered to remove unreacted 6-chloropurine. The filtrate was washed (NaHC303,water), dried (3IgPO4), and pyridocarbazole isomeric with olivacine). A recent evaporated to dryness. The residue was triturated with ethanol synthesis4 of ellipticine, but in very low yield, is similar t o remove additional 6-chloropurine, and the filtrate and filtered was decolorized with Norit before it was evaporated to dryness in outline to the sequence in Scheme I which is conin L'UCUO. Petroleum ether extraction of this residue partially venient for quantities of XI1 and XIII. Preparation removed the blocked sugar contaminant from the insoluble oily of st p-chlorophenyl derivative of olivacine was underproduct', which was then dried in vacuo; yield 2.0 g (46%). taken, because of the often encountered activity enThin layer chromatography o n silica gel H (Merck) using CHCLhancement with thic, moiety, but the chlorine was lost ethyl acetate (3: 1 ) iindicated the material \?as suitable for use as u i i iiit'ermed iate. in the final dehydrogenation and a simple phenyl
P
Acknowledgment.-The authors are indebted to Dr. W. ,J. Barrett and members of the Analytical Section of Southern Research Institute ~ v h operformed the spectral and analytical determinations, to Dr. W. C. Coburn, Jr., arid hlrs. 21. Thorpe for their interpretation of the proton magnetic resonance spectra, and t o Miss E. A. Dulmage for the cytotoxicity data reported herein.
derivative XIV resulted. X similar sequence (Scheme 11) was uhed to prepare the benzoolivacine XXVII. SCHEMEI1
NH,NH
QCN CH3 XV
+
Preparation and Antitumor Activity of Olivacine and Some New Analogs' CARVL\V. NOSHER, C ~ B O R S E P. CREWS,EDWARD 11. A c w pi, ASU h o p i GOODMAN
XVII, X = CN XVIII, X = COOH XIX, X = COOEt
\
XYI
Life Sciences Research, Stanford Research Institute, illenlo Park, California Received September 7 , 1965
Preliminary reports from the Cancer Chemotherapy Sational Service Center' of potentially useful antitumor activit'y with the alkaloid olivacine (XII) necessitated the synthesis of large quantities for further biological t'est'ing. This has been accomplished (Scheme I) by revising a previous synthesis2 to reduce the nurnher of steps and avoid the use of diazomethane. The tn-o previous syntheses2, were useful niairily for the sinal1 amounts required for structure confirniation of XIT. Structural requirements for activity in substituted 1)yridocarbazoles were studied briefly by the prelmat'ion of several analogs of XII. demethyl derivative X I J I of olivacine was easily accessible by Scheme I ; this compound (XIII) is also a deniethyl derivative of the alkaloid ellipticine (the 5,ll-dimet'hyl(1) This work x a s carried out under the auspices of t h e Cancer Chernotherapy Sational Service Center, Sational Cancer Institute, Sational Institutes of Health, Public Health Service, Contract N o . PH-43-64-500. T h e opinions espressed in this paper are those of the aiit,liors and not necessarily those of t h e Cancer Chemotherapy National Service Center. (2) J. Schmutz and H. Wittwer. Helu. Chim. A d a , 43, 793 (1960). ( 3 ) E. Xenkort and li. G. Dave, J . A m . Chern. Sac., 84, 04 (1962).
XX, X X
XXI, XXII, XXIII, XXIT', XXV,
= COOEt = CH,OH X = CH=O X = CH=CHNOz X = CHzCHzNHz X = CHzCHzhHAc
XXVI
J/ CH3 1
XXVII
Biological Data.5-On the basis of incomplete testing results, the alkaloids related to olivacine and the corresponding dihydro compounds seemed to be poten(4) T. R . Govindachari, S. Rajappa, and V. Sudarsanam, Indian J. Clrem., 1, 247 (1063). ( 5 ) The compounds were screened under the auspices of the Cancer Cliernotlierapy National Service Center according to its protocols. outlined in Cancer Chemotherapy Rept., 25, 1 (1962).
