NOTES
March 1966 under reduced pressure at 70", a t which temperat'ure it decomposed to give the crude 3-fluor0 compound. This crude material was dissolved in benzene, filtered, and chromatographed on alumina (Woelm, neutral, activit,y grade I). The product was eluted with l0y0 ether in benzene and recrystallized from methanol to give 0.24 g (247,) of 111, mp 178-180°, [CY]% +143". Anal. Calcd for ClsHzlFO: C, 79.38; H, 7 . V ; F, 6.98. Found: C, 79.39; H, 8.00; F, 6.83. 3-Fluoroestra-1,3,5(lO)-trien-l7fl-o1 (VI).-A solution of 1 .OO g (8.60 nimoles) of 3-fluoroestra-1,3,5( 10)-trieii-17-oiie (111) in 100 nil of ethanol was treated with 4 ml of 10% XaOH solution and 0.53 g (14.0 ninioles) of XaBH4. After 1 hr a t room temperature the solution was poured into water, aiid the product was extracted with ether. The extract was washed with water, dried, arid concentrated to dryness. The residue was recrystallized from hexane to yield 0.65 g (65Yc) of TI, mp 112-114", [ a ] " D +84O. d n a l . Calcd for C18Hz3FO: C, 78.80; H, 8.45; F, 6.92. Found: C, 79.00; H, 8.T1; F, 6.67. 3-Fluoro-17~u-methylestra-l,3,5( lO)-trien-17p-ol (VII).-A solution of 0.84 g (3.09 mmoles) of 3-fluoroestra-1,3,5( lO)-trien-lTotie (111) in 80 ml of ether was treated with 3.5 ml of 3 M methylniagnesium bromide solutioii. The resulting mixture wa. and refluxed fur 1 hr, cooled, and treated with NHlCl solution. The ether layer was separated, washed with water, dried, arid concentrated to dryness. The residue was recrystallized from ether-petroleum ether to give 0.40 g (4557,) of 1'11, mp 108-110", [ a ] * ' D +58'. Anal. Calcd for G9HZ&FO: C, 79.13; H, 8.74; F, 6.59. Found: C, 78.90; H, 8.75; F, 6.24.
Acknowledgment.-The authors wish t'o thank hlr. C. E. Childs and his staff of our Microanalytical Laboratory and Dr. J. 11. T'andenbelt arid his staff of our Physical Chemistry Laboratory for their valuable technical assistance. The authors are indebted to Dr. 0. D. Bird, Dr. G. Rodney, and Dr. AI. R. Callantine for the pharmacological activities presented in this paper.
Synthesis of Some Substituted Tryptophols of Possible Physiological Importance and a Study with 3-(2-Acetoxyethyl)-5-methoxyindole (5-Methoxytryptophol 0-Acetate) on Sexual blaturation ROBERTG. TABORYKY A N D PETERDELVIGS~ C'leceland Clinic, Research Dmision, Cleveland, Ohzo 44106 Recezved July 14, 1966
The unique psychopharmacological effects of ethanol, easily formed by biological processes, have been ai)preciated since antiquity. Recent studies have indicated that hydroxyl derivatives of histamine,2a the catecholainiiies,2b'Cy-aminobutyric acid,3 tryptamine,4 and serotonin5 can be metabolites of these biogenic amines. Furthermore, the resu1t)ant biogenic alcohols may possess physiological properties. An example is y-hydroxybutyric acid, a metabolite of y-aniinobutyric w i d 3 which has effective sleep-producing 1roperties.6 (1) Research Fellow supported by Training Grant 5126-08 from the National InsLitutes of Health, U. S.Public Health Service. (2) (a) T. Xakajima and I. Sane, Biochim. B i o p h y s . Acta, 82, 260 (1964); (I>) J. Axelrod, I. J. Kopin, and J . P. hIann, ibid., 36, 576 (1969); (c) hI. Goldstein, A . J. Freidhoff, S. Pomeranta, and C. Simmons, ibid., 39, 189 (1960). (3) S.P. Uessman and 1%'. S . Fishbein, >Vatme,200, 1207 (1963). ( 4 ) A. A. Smith and S. H. Wortis, Biochim. Biophys. Acta. 40, 569 (1960). (5) S.Kveder, 9. Iskric, and I). Keglevic, Biochem. J . , 85, 447 (1962).
251
Tryptophol was identified as a metabolite of tryptamine in rats pretreated by the aldehyde dehydrogenase blocking agent, d i ~ u l f i r a m . ~Kveder, et presented good evidence that 5-hydroxytryptophol may be the second most important metabolite of serotonin in the rat, rather than X-acetylserotonin as first thought.' Bartholini, Pletscher, and BrudereP found a neutral metabolite of serotonin released from isolated blood platelets by reserpine arid have presented chromatographic evidence that it is 5-hydroxytryptophol. Evidence has also been presented for the presence of ,?-methox yt ryptophol and 5-hydrox yt rypt o p hol in pineal tissueg rather than P-carbolines, once thought to be constituents.'O It was necessary for us to prepare a collection of substituted tryptophols, the acetate esters, and related acids for our studies of metabolism, isolation, and pharmacology of these substances. Acetylation alters markedly the hormonal properties of hiiethoxytryptamine. The latter is without effect on frogskin lightening while the acetylated analog (melatonin) is a potent frog-skin-lightening h o r n ~ o r i eand ~ ~ diq~~~ plays marked inhibitory effects on the incidence of estrus in rats.13 Therefore, it was of importance to iee if chain acetylation of 3-methoxytryptophol might also produce a compound with special biological properties not qeen i n the precursor. 3-Methoxytryptophol was prepared by the lithium aluniinum hydride reduction of either hiiethoxyindole-3-glyoxyloyl chloride or 5-niethoxyindole-3-acetic acid. The reduction of the former produced a considerable amount of by-product which could not be removed by distillation or fractional crystallization. However, the 3-methoxytryptophol could be purified by conversion to a solid picrate derivative. Reduction of the acid gave a better product which was easily Ilurified without recourse to the picrate. I t was 21 yellow oil which was acetylated with acetic anhydride to give mi oil that did not solidify, but that could be ronverted into a useful picrate. The metabolic fate and effects on sexual development of 3-(2-acetoxyethyl)-3-methoxyindole in the female rat were inveqtigated; the latter study is reported in thi, paper, ant1 the former will be reported elsewhere. Other substituted tryptophols prepared were cornpounds which could be potciitial metabolites of 5methoxytryptophol 0-acetate and serve as chromutographic standardq. For the selertion of authentic. c~ompound~ to he synthesized for chromatography, three poqqible nietabolic transformations n-ere anticipated. These are described together with iynthetic route< (Chart I) bcing: (1) &hydroxylation oiily to give V I I ; ( 2 ) 6-hydroxylation and hydroly-is to give V ; (3) 6-hydroxylation, ehter hydrolysis, and osidation to give 111. Uqually, indole-3-acetonitrile* cat1 (6) H. Lalmrit, J. AT. Jounay, J . Gerard, and F. Fabiani. Presse M e d . . 68, 1867 (1960); 11. Hlumenfeld, R. Suntay, and AI. Harmel, Anesthesia Atralu e s i a , Current Res., 44, 721 (1962).
( 7 ) W.A l . McIsaac and I . H. Page, J . Biol. Chem., 234, 858 (1959). (8) G. 13arthoIini, A. Pletscher. and H. Rruderer, .Vature, 203, 1281 (1964). (9) Vi. 31. hlcIsaac, G. Farrell, R. G. Taborsky, and A . S . Taylor, S c i e n c e , 148, 102 (1965). (10) G. Farrell and JV. Xl. AIcIsaar, Aiclr. Biochem. Btophys., 94, 543 (1961). (11) A . 13. Lerner and J . D. Case, J . Inuest. Dermatol.. 32, 211 (1959). (12) A . B. Lerner, J. D. Case, and R. V. Heinzelman, J . B m . Chem. SOC., 81, 6084 (1959). (13) R. J. Wurtman, J. Axelrod, and E . Vi-.Chu, Science. 1 4 1 , 277 (1963).
NOTES
/OH-
=
i
m
"*IH4
..
H
PI
I \pt
I-.\ 1-13
I-( I]-.% 11-13 11-4' 1I I-.i "€3
III-('
253
SOTES
March 1966
A portion was converted to the picrate,z1 nip 116-116.5" Therefore, the observations were divided so that data (lit.l9 mp 117-118"). from the first thirteen observations could be compared 3-(2-Acetoxyethyl)-5-methoxyindole Picrate.-A solution of tvith the last 13. The recults from the control values 500 mg (2.62 mmoles) of 5-methoxytryptophol in 9 ml of acetic anhydride was heated for 5 hr at 90". Solvent was removed (I1 and 111) showed little difference between earlier in vucuo to yield 510 mg of 3-(2-acetoxyethyl)-5-methosyindole (11-B arid 111-€3) and later (TI-C and 111-C) observaas a tan oil. I t was dissolved in a small amount of CHCl3 and tions; in expt I the difference of means between added to 500 mg of picric acid in 6.0 ml of CHCI,. Partial evapoI-B and I-C n-aL: 10,537,. On taking the ratio of ration and cooling yielded 821 mg (68rc) of the desired picrate, this to the btaridard deviatioii =t3.42 ( t value), one finds mp 95-'35.5°, unchanged on crystallization from CHC1,. ;Inal. Calcd for C19H,,n',010: C, 48.33: H, 3.92: X, 12.12. that the quotient exceed.; the critical value of t a t the Found: C, 49.39;H, 4.07: N, 11.92. 1% probability level. 6-Benzyloxy-5-methoxyindole-3-aceticAcid (II).-Powdered It appears that 5-niethoxytryptophol 0-acetate 6-benzylox~--5-niethoxyindole-3-acetonitrile*~ (3.10 g, 1.1 X exerts a considerably greater inhibitory effect 011 estrus 10-2 niole) 25.0 g of KOH, 100 nil of water, and 120 nil of proin immature thurl in mature animals. There \vas no pylene glycol Tvere refluxed (stirring) for 18 hr. The mixture was cooled, diluted with water, treated with charcoal, and filtered. significant decreahe ill ovarian-to-body neight ratios The filtrate was acidified to pH 3 a i d the solid product) was or of body Treights of the estrus-inhibited group (Table extracted with CHC13. The conibiued extracts were reducaed I). It is concluded that 5-methoxytryptopliol 0- t o 10 nil, cooled, and filtered to yield 1.33 g ( 4 0 7 ) of air-dried acetate has quantitatively siinilar inhibitory effectc product, mp 173-174", after wabhiiig with n-hexane. .I 1 : l on rat estrus as nielatoiiiri aiid 5-metlioxytry~)tophol. CHC13-ether solution of 47 mg of the acid \\-as treated with 30 mg of 5-methoxytr>-ptamine to give a quantitative yield of the salt Recent studies of our+i demoiiitrated that 5-niethoxyderivative,14 mp 152-153'. One stallization from tolueiir tryptophol 0-acetate i 4 nietabolizeti differeiitly arid yielded an analytical sample, with melting point unchanged. niore slo~vly than j-iiiethosytryptophol, However, Anal. Calcd for CI9H,lX;,Oj: C, 69.46; H, 6.23: S . X.3S. apparently the biochemical changes produced by acetFound: C, 69.59; H, 6.13; N, 8.15. 6-Hydroxy-5-methoxyindole-3-aceticAcid (111) (5-Methoxyylation d o not result in greater inhibition of rat eL:trus. Experimental Section All indolic intermediates were purchased from the Regis Chemical Co., Chicago 10,111. Reduction of 5-Methoxvindole-3-nlvox~lo~l Chloride with Lithium Aluminum Hydride.-A soGtion of 2.35 g (1.0 X 10-2 niole) of 5-niethoxyindole-3-glyoxyloyl chloride18 in a small amouiit of dry tetrahydrofuran ( T H F ) was added to 4.0 g (0.1 mole) of lithium aluminum hydride in 60 nil of THF, and the mixture vias stirred niagnetically overnight a t room temperature. Eweis hydride and the lithium aluminum complex were destroyed by water iii THF. 1 1 1 solids were removed by suction filtratioii, and the filter cake v a s washed with ether. The clear filtrate was evaporated t o dryness under vacuum. Distillation of the residue gave 1 g of a major fraction, bp 218-220" (5 nim). iSi1ic.a gel thin layer chroniatography of the fraction (10% methaiiol iii CHC1,) gave two spots of Rf 0.75 and 0.90. -1number of variation5 of the reaction conditions n-ere used in attempts to get a single product. None were successful. However, the pimate had a good melting point (115-116", lit.19 115-115°) and produced a single-spot chromatogram. Preparation of 5-Methoxytryptophol by Reduction of 5Methoxyindole-3-acetic Acid.-5-Methoxyindole-3-acetic acid was prepared by the hydrolysis of 5-methoxyindole-3-acetoi1itrile which %vasprepared from the niethosulfate of 5-methoxygramine.20 .I mixture of 0.2 g (5.3 mmoles) of lithium aluminum hydride aiid 0.5 g (2.4 ninioles) of 5-methosyindole-3-acetic acid irnp 146-11'3') in 115 nil of anhydrous ether was stirred a t room temperature for 1 hr. Excess hydride was destroyed with 5-7 nil of water, aiid the reaction mixture was treated with 25 nil of 1 0 7 XaOH. The layers were separated, and the aqueous phase \vas extracted with three 15-ml portions of ether. The combined ether portion was dried, filtered, evaporated, and dried in a vacuum desiccator to yield 0.4 g (87%) of 5-methoxytryptophol as a viscous j-ellow oil. Thin layer chromatography with 1: 10 iiiethaiiol-CHCl3 gave a discrete, Ehrlich-positive spot a t Rf 0.67 with a trace of impurity indicated by a second faint spot. Attempted crystallization from ethyl acetate and n-hexane yielded ail oil which n-as chromatographically pure, but did not solidify. I n u L Calcd for C I I H ~ ~ N OC,~ : 69.09; H, 6.85; N, 7.33. Found: C,68.83; H,6.92; S, 7.55.
(17) Submitted for publication. (18) T. Kralt, W. J. Asma, H. H. Haeck, and H. D. Rloed, Ree. Trau. Chzm., 80, 321 (1961). (19) T. Hoahino and I
