Journal of Medicinal Chemistry, 1971, Vol. 14, No. 3 259
NOTES
anthracene and have them screened for possible antitumor activity. Of the several possible approaches, it appeared, based on our experience with benz [alanthracene derivatives,6 that the best approach would be to attach the mustard after the polycyclic system had been built. Therefore 7-(4-methylphenyl) benz [alanthracene' was photochemically converted into 7-(4-bromomethylphenyl)benz[alanthracene. This was treated with an amino alcohol leading to the polycyclic amino alcohols sho\\-n in Table I which were isolated as hydrochlorides. These were converted into the corresponding mustards. TABLF: I ALCOHOLS A N D MUSTARDS D):RIVI,;D FROM ~ - B E N Z [ANTHRACICN-7-YL21ENZYLAMINE U]
Qr
(9) Two additional mixed N and S mustards were prepared: p-bena[a]antliracen- 7 - y ~ (~2 [-( ~ - c ~ i l o r o e t ~tliiolet~iyl) iyI) -N-etiiylbenaylamine H C I , (Ca1H:oCINS.HCI) C, H, C1. N , S, mp 153-154' (70%); p-bena[a]anthracen7-yl-N-(3-[(2-chloroethyl~tliiolpropyl)benzylamine~HCI, (CsoIIzsClXS) C : calcd, 71.1: found, 68.0. Althougli a satisfactory C analysis could not be obtained, this compound was included in the antitumor screen. Anal. was satisfactory for H , CI, N , S, mp 211-212' (60%). (10) C: calcd, 71.1; found, 65.7. .tltliougli a satisfactory C anal. could not be olitained, this compd \!as included in tlie antitumor screen (11) CI: calcd, 8.6; found, 8.1. S : calcd, 7.8; found, 7 . 3 .
CII,N(CHL),,X.HC1
Yield,
It
S
11
7%
MP, 'C
CH3 OH 2 80 202-203 80 227-228 CZHS OH 2 CH2CH2OH OH 2 80 184-185 H OH 3 80 218-219 CH3 75 209-210 c1 2 2 75 220-221 CzHr c1 70 203-204 2 CHzCH2Cl C1 90 244-245 H c1 3 All compds were analyzed for C, H, C1, N. 78.8; found, 78.3. c C: calcd, 76.0; found, 75.5. 70.4; found, 70.9. e C : calcd, 75.3; found 74.8.
(10 g, 0.022 mole) in CHCL was added 5.0 g (0.064 mole) of 2mercaptoethanol dissolved in NaOEt and 4 g of N a in 100 ml of EtOH. The soln was refluxed for 2 hr and then cooled and poured into HIO. The product was extd with EtzO, dried (MgS04), ethereal HC1 was added, and the mixture was cooled overnight (refrigerator). The solid was filtered and dissolved in 200 ml of CHCl,, excess S02Clz was added, and the mixture was refluxed for 2 hr. The solvent and excess S02C12 were distd, and the residue was recrystd 3 times from EtOH, yielding 7.2 g (65%), mp 182-183.0 Anal. (CUH&lNS HCl), C,'O H, C1, N, S. p-Benz [a]anthracen-7-ylbenzyl 2-Chloroethyl Sulfide.-To a soln of 10 g (0.025 mole) of 7-(Cbromomethylphenyl)benz [a]anthracene in EtOH was added 5.0 g (0.065 mole) of 2-mercaptoethanol dissolved in NaOEt. The s o h was refluxed for 2 hr, cooled, and poured into H10. The product was extd with EkO, the soln dried, and the solvent distd, leaving an oil which was crystd from EtOH giving the alcohol as bright yellow plates, mp 116-117', 8.4 g (85%). Anal. (CZTHZ~OS) C, H, S. This alcohol was dissolved in CHC1, and excess SOzClt was added. The soln was refluxed for 10 min and then taken to dryness under reduced pressure. The resulting oil was crystd from EtOH and gave 7.0 g (80%) of product, mp 108-109'. Anal. (Cz7HZ1ClS) C, H, C1, S.11 Biological Testing.-All the mustards were tested by CCNSC against L-1210 lymphoid leukemia and none was found to be active.
. . .. .
C: calcd, d C: calcd,
Experimental Sections
7-(4-Bromomethylphenyl)benz[a]anthracene.-To a s o h of 64 g (0.20 mole) of 7-(4-methylphenyl)benz [a]anthracene7 in 800 ml of CClr heated under reflux, there was added 3 g of benzoyl peroxide followed by 36 g of NBS (excess), added i n small portions. The soln, while being irradiated with two 200-W lamps, was refluxed for 90 min after all the NBS had been added, then cooled, and filtered. The filtrate was concd to 200 ml and filtered, and the filtrate was taken to dryness. The yellow solid was crystd from heptane and gave 64g (80%) of white rhombic crystals, mp 158-159'. Anal. (C2;HI7Br)C, II,Br. p-Benz [a]anthracen-7-yl-N-(2-hydroxyethyl).N-methylbenzylamine.HCl.-To a sohi of 10 g (0.025 mole) of 7-(4-bromomethylpheny1)benz [alanthracene in 200 ml of C&s there was added 2 ml of N-methylethanolamine and the mixture was refluxed for 4 hr. The soln was cooled, washed (HzO)3 times, and dried (MgSOd). When ethereal HCl was added, the product pptd and was recrystd from dry EtOH. p-Benz [a]anthracen-7-yl-N- (2-chloroethyl)-N-methylbenzylamine.HCI.-The above amino alcohol (10 g, 0.023 mole) was added to 500 ml of CHCb and heated under reflux. Excess pure S0,ClZ was then added slowly and the mixture was refluxed for 90 min. Removal of the solvent and excess SO&lZ left a solid which was crystd from dry EtOH. p-Benz [a]anthraoen-7-yl-N-( 2- [(2-chloroethyl)thio]ethyl ) - N methylbenzylamine.HC1.-To a hot soln of the above mustard (6) F . A. Vingiello, L.Ojakaar, and R . Kelsey, J . M e d . Chem., 8,144 (1955). (7) F . A. Vingiello, A. Borkovec, and J. Shulman, J . Amer. Chem. Soc.,
77, 2320 (1955). (8) All melting points were taken on a Fisher-Johns melting apparatus and are uncorrected. Where analysea are indicated only by symbols of the elements, analytical results obtained for these elernenta were within &0.4% of the theoretioal values.
.. .-
Synthesis a n d Anticancer Activity of Cytosine Arabinoside 3-N~Oxide (Ara-C 3-N-Oxide)' 1tAYMONI) P. P A N Z I C A , 2 LlCROY B.
IXOLAND K. ROBINS,AND TOWNSICND*
Dcpartment of Chemistru and Dcpartnwnt of Hiopha~wtaccuticalScicnces, University of Utah, Salt Lake City, Utah 84112 Acceived July 16, 1970
Cytosiiic tlrabi~ioside~ has been sho\vii to undergo :L rapid enzymatic deamination in mtm to form arabinofuranosyluracil, an inactive metabolite. 4--7 The ilihibition of pyrimidine riuclcoside deaminase, the enzyme which causes this process, has been the subject of much study. Tetrahydrouridiiie (THU, H4-U, 3,4,5,G-tetrahydrouridine) has been shown to bc an effective inhib-
(1) This work was supported in part by Research Contract P H 43-65-1041 with Chemotlierapy, National Cancer Institute, National Institutes of Health, Public Health Service. (2) The recipient of a University of Utah Research Committee Fellowship, 1968-1970. (3) Synonyms for cytosine arabinoside are: Ara-C, cytarabine, and 1-8D-arabinofuranosylcytosine. (4) G . W. Camiener and C. G . Smitli. Bioehcm. Pharmacol.. 14, 1405 (1965). (5) R . V. Loo, M. J. Rrennan, and R . W.Talley, Proc. .4mer. A s s . Cancer Res., 6, 41 (1965). (6) R . J. Papac, W.A. Creasy, P. Calabresi, and .I,I). Welch, i b i d . , 6 , 50 (1965). (7) W.A. Creasey, R. J. Papao, M . E. Markiuo, P . Calabresi, and A . D. Wslch, Biochem. Pharmacol., 111, 1417 (1966).
260 Journal of Medicinal Chemistry, 1971, Vol. 14, No. 3
NOTES
TABLE I LYMPHOID LEUKEMIA L1210 Host
BDFi BDFi BDFi BDFi BDFi BDFl
Dose, mdkg
400 40.0 20.0 10.0 5.00 400
Survivors
Animal wt diff (T - C )
6 /6 6 /6 6 /6 5 16 6 /6 6 /6
-1.1 -0.7 -1.8 -0.5 0.3
-3.3
itor of this enzyme and to enh:mce the anticancer effect of Ara-C when both are administered together.8j9 These findings prompted us to investigate the rational design of a structural modification of cytosine arabinoside which should provide :LI~ increased resistance toward deamination with an increase in anticancer activity. The biological activity of cordycepin, which undergoes a similar enzymatic deamination, can be iricreased by n facile conversion to cordycepin 1-N-oxide. lo Cordycepin 1-N-oxide has been fsund to be resistant toward this enzymatic deamination and the slow enzymatic reduction back to cordycepiri in the tumor cell provides a more efficient admiiktkttiori of cordycepin to the desired site. NHI I
OO+ -A” 3 N
I
Hm44 HO
1
In t ~ n:ittempt to provide similar tlierapeut,ic results, cytosiiie arabinoside 3-N-oxidc (1) \vas prepared in our 1abor:ttorjr.I l a v b Antitumor Evaluation. h e pro1imin:wy rcsult s obtained from the anticancer testiiig of cytosine arabinoside 3-N-oxide are shou 11 in Table I and cvaluation of thc activity is in accordance uith the criteria of the Cancer Chemotherapy National Service Center. From the testing data available (Table I) a t the present time, it is evident that cytosine arabinoside 3-N-oxide is :Lpotential inhibitor of lymphoid leukemia L1210. Experimental Section13 Cytosine Arabinoside 3-N-Oxide (1 ).-To a sohi of cytosine arabinoside (2.0 g, 8 mmoles)l4 ill AcOH (40 ml) a t 65’ was added (8) G . W.Camiener. Biochem. Pknrtnncol.. 17, 1981 (lY68). (9) G . L. Neil, T . E. Moxley and R . C . hlanak, Abstracts, Tentli International Cancer Congress, Houston, Texas, M a y 1970, No. 674. (10) S. Frederiksen. Biochim. Biophys. Acta, 76, 366 (1963). (11) (a) This preparation v a s accomplished by t h e method of T. J. Delia, it4. J. Olsen, and G. 13. IJroivn, J . 078. Ckem., SO, 2765 (1965). (b) G. B. Brown and coworkers have pointed out t h e chemotherapeutic advantages of N-oxides v s . t h e parent compound; see G . Levin and G . U . Brown, J . M e d . Chem., 6, 825 (1963),and G . 13. liroivn, G. Levin, S. Murphy, A. Sele, 11. C. Reilly, G . S. Tarnowski, F. A. Schmid, M .N . Teller, and C. C . Stock, ibid., 6, 190 (1965). ( 1 2 ) Testing \vas performed under the auspices of t h e Cancer Chemotherapy National Service Center. (13) Satisfactory anal. d a t a (C, H, N within rt0.4% of theor values) were obtained from Heterocyclic Chemical Corp., Harrisonville, Mo. T h e melting point v a s determined on a Thomas-Hoover melting apparatus and is uncorrected. T h e uv s ~ e c t r awere recorded on a Beckman DK-2 spectro-
Tumor evaluation
(T/O
(54
11 ,319.0 12.3/9.3 12 0/9.3 9.3/9.3 I 1.5/9,3 16.4/9.8
132 129 100 123 167
Test status
12,i
I
11 22P 22P 22P 22P I .5
m-ClCeHaCOaH (5.0 g, 25 mmoles). The reactioii mixture was heated at this temp for 1.5 hi, arid theii poured slowly into H 2 0 (500 ml) with stirriiig. The iiisol org acids which pptd were removed by filtration, and the fi1trat)ewas evapd to dryness (40’) in vacuo. The residue was dissolved iri a miiiimum of 90% aq MeOH and then added dropwise with stirring to EtOAc (300 ml). The granular product, was collected by filtratioii and then triturated wit.h boiling 1i:tOR (2.5 ml) to remove any traces of starting material. The insol solid was recrystd from a RleOHEtOAc mixt,ure to give 1.12 g (54%) of product. The .&‘-oxide was homogeiieoris o i l paper chromatography i i i solveiitr A, B, arid C and gave a dark red color with FeC18. Aii mal. samplc was obtained by recrystn from MeOH-EtOAc: mp >130 dec; [ a I a 7 D $- 109.6” (C 1.0;*,,1 1 9 0 ) ; 273 liln (E 9300); A:!’ 272 (6540), 226..i (16570): 271 (6480), 223.5 (19600). Anal. (C~HiaN306)C, H, N . The product had IZf valries of 0.49, 0.05, aiid 0.34 on paper chromatography iii solvent’sA, B, aiid C, resp, as compared with cytosine arabinoside which had I& values of 0.57, 0.14, and 0.52, resp. pliotoineter. The optical rotation was obtained with a Perkin-Elmer Model 141 automatic digital readolit polarimeter. Paper cliromatograms were r u n on Wliatman No. 1 clirornatograpllic paper using the descending teclinirliie. Short-wave uv light (254 nm) \vas used t o detect t h e 8pot.s. : 2, Cliromatograpliic solvent systems: A , 1% ail ( N l 3 ~ ) ~ S O e i - P r O 1l ~ ( v / Y ) ; 13, n-13uOll satd \\.it11 1120; C, n-PrOH-NH4OII (sp gr O.SO)-HxO, 6 : 3 : 1 (v/v). (14) Tile autliors wisli t o tliank Ijrs. H . 13. \Vood, J r . , and It. E. Engle of t h e Cancer Chemotherapy National Service Center, National Cancer Institute, National Institutes of Health, Public Healtli Service, for tlie generous gift of cytosine arabinoside monoliydrocliloride (NSC-63878).
Further Studies in Substituted 4H-1,2,4-Triazoles for Possible Hypoglycemic Activity M. Y. MHASALKAR, M. H. SHAH,S.T. NIKAM, K. G. ANANTANARAYANAN, AND C. 1’. I)ELIWAL.\* Haflkine Institule, Parel, Bombay-18, India Received September 81, 1970
Earlier we reported’ that 4-ethyl-~~-p-sulfamoyl~lieny1-4H-1,2,4-triazole-3-thiol (I) and 5-p-chlorophenyl4-ethyl-4H-1,2,4-triazole-3-thiol (11)possess potent and prolonged hypoglycemic activity. 1”urther variations in these compounds revealed that the E t group at posiN-N R-C,
II
II
N
AC-SH
I
I
I, R= p-H,NSO&H,
II,R = P-CIC~H~
tion 4 favored this property. The present communication pertains to the replacement of the SH group in po(1) h i . Y, Mhasalkar, M .H . Shah, S. T . h’ikam, K. G. Anantanarayanan, and C. V. Deli\vala, J . M e d . Ckem., 18, 672 (1970).
