EP0773933A1 - Optically active isomers of dihydrexidine and its substituted analogs - Google Patents

Abstract

Optically active hexahydrobenzo[a]phenanthridines of formula (I) wherein R is hydrogen or C1-C4 alkyl; R1 is hydrogen or a phenol protecting group, X is fluoro, chloro, bromo, iodo or a group of the formula OR5, and R2, R3, and R4 are independently selected from the group consisting of hydrogen, C1-C4alkyl, phenyl, fluoro, chloro, bromo, iodo, or a group -OR1 are disclosed. The method of resolving the racemic trans-hexahydrobenzo[a]phenanthridines into their component enantiomers is also disclosed. Pharmacological evidence reveals that only one of the enantiomers of a preferred phenanthridine, dihydrexidine, the (6aR, 12bS)-(+)-isomer, is active in binding to both D1-like and D2-like dopamine receptors. Various other compounds, compositions, and methods of using the optically active stereoisomers are likewise disclosed.

Description

OPTICALLY ACTIVE ISOHERS OF DIHYDREXIDINE AND ITS SUBSTITUTED ANALOGS

Government Funding

Aspects of the present invention were supported by PHS Grants MH42705, MH40537, Center Grants HD03310, MH33127, and Training Grant GM07040. The United States Government has certain rights in the present invention.

1. Field of the Invention

The present invention relates to optically active s t e r e o i s o m e r s o f t r a n s - dihydroxyhexahydrobenzo[a]phenanthridine (dihydrexidine) , their resolution, compositions, and methods of use. In particular, the (+)- and (-)-isomers of dihydrexidine were resolved from the racemate using a non-classical technique after initial attempts using classical techniques failed. Furthermore, pharmacological evidence suggests that the biological activity previously associated with the racemate, with respect to J oth O - like and D₂-like dopamine receptors, resides in only one of the stereoisomers, the (+) -isomer. Because each of these receptors constitutes several different molecular forms, each of which in turn is encoded by distinct genes and is associated with opposite biochemical effects, i.e., D^like for stimulation vs. D₂-like for inhibition of cAMP synthesis, the discovery that just one of the stereoisomers is active in both types of receptors is indeed surprising. The present invention finds use in a number of diagnostic, prophylactic, and therapeutic applications, including the alleviation or modulation of certain neurological disorders. 2. Background of the Invention

Dopamine functions as a neurotransmitter in both the central and peripheral nervous systems. Dopamine receptors have been implicated in several neurological disorders, such as schizophrenia and Parkinson's disease, as well as in vascular regulation. Additionally, dopamine receptors are the accepted loci of action of many psychotropic drugs, including amphetamine, cocaine, and the neuroleptics. Thus, ligands selective for dopamine receptors are important as basic research tools and potential therapeutic agents.

Although the field is in a state of flux, the commonly accepted classification divides dopamine receptors into two general classes called D₂ and D₂ (Kebabian, J. and Calne, D.B., in Nature 1979, 277, 93-

96) , with each group comprising several molecular forms. The "Di-like" receptors include at least two gene products (the D_la and the D_lb or D₅) , which are linked functionally to stimulation of cAMP synthesis, and which preferentially recognize 1-phenyl-tetrahydrobenzazepines

(e.g., SCH23390) vs. benzamides (e.g., raclopride or sulpiride) . The "D₂-like" receptors come from at least three genes, and include multiple splice variants. The "D₂-like" receptors (D_2l0ng, D_2short, D₃, and D₄) sometimes are linked to inhibition of cAMP synthesis, and have the opposite pharmacological specificity from the D^like receptors (i.e., having much higher affini ty for spiperone or sulpiride vs. SCH23390) .

Because of a prevailing view that D₂-like receptors were responsible for almost all of the clinically important actions of dopamine agonists and antagonists, Di-like receptors received little attention until the mid-1980s. With the availability of SCH23390 (the first D_x selective antagonist; see, Iorio, L.C. et al. , in J^". Pharmacol . Exp. Ther. 1983, 226, 462-468), it soon became clear that the O -receptor had profound psychopharmaco- logical effects and interacted in important ways with D₂ receptors. (Mailman, R.B. et al. , in Bur. J. Pharmacol . 1984, 101 , 159-160; Christensen, A.V. et al. Life Science 1984, 34 , 1529-1540.) Yet while several excellent antagonists were made from the l-phenyl-tetrahydro-3- benzazepine series, the resulting agonists (e.g., SKF38393, whose structure is depicted below) were generally only of partial efficacy relative to dopamine (i.e. , in stimulating dopamine-sensitive cAMP synthesis) .

SKF38393

Despite this potential limitation, SKF38393 and related partial agonists have been used in many studies of D_x receptor function because they were relatively selective, and because no alternatives were available.

Nichols, D. E. disclosed, in U.S. Patent No. 5,047,536, novel ligands for dopamine receptors which comprised generically certain t ra n s - hexahydrobenzophenanthridines of the formula (1)

wherein H_a and H_b are trans across ring fusion bond c, R is hydrogen or -^-^ alkyl; R_x is hydrogen, benzoyl or pivaloyl; and X is hydrogen, chloro, bromo, iodo or a group of the formula 0R₂ wherein R₂ is hydrogen, benzoyl or pivaloyl.

The biological activities of these compounds were described as ranging from potent dopamine-like activity affecting both D-l and D-2 dopamine receptor subtypes to specific dopamine D-l receptor antagonist activity. Although numerous compounds exemplifying the generic class are provided, the specification of this patent contains neither a description of the stereoisomers of any of the compounds nor of their potential pharmacologic behavior.

These previous studies culminated in the synthesis of racemic trans-10, 11-dihydroxyhexahydrobenzo [a]phen- anthridine (dihydrexidine, 2) , the first compound shown to be a potent and bioavailable, full efficacy D_x agonist. (Brewster, W.K. et al . , in J. Med. Chem. 1990, 33 , 1756-1764; Lovenberg, T.W. et al. , in Bur. J". Pharmacol . 1989, 166, 111-113.) In Brewster, W.K. , supra, the authors speculated on what possible activities may reside in one enantiomer of dihydrexidine versus another. Because no studies had actually been carried out on the individual enantiomers, such speculation only highlights the uncertainty of what properties each enantiomer may or may not exhibit.

In addition to its use as a pharmacological probe,

2 has been shown to have impressive antiparkinsonian action in the MPTP monkey model. (Taylor, J.R. et al . , in Eur. J. Pharmacol . 1991, 199, 389-391.) More recently, similar antiparkinsonian effects were reported for members of another new class of full D_x agonists, the phenyl aminomethylisochromans. (DeNinno, M.P. et al., in J. Med. Chem. 1990, 33 , 2948-2950.) The structure of one such compound, ( 1R, 3S) - 1- (aminomethyl) - 3 , 4 -dihydro-5, 6-dihydroxy-3-phenyl-lH-2-benzopyran (A70108) is shown below.

A70108

Such data underscore the importance of understanding the pharmacophore (those interrelated steric and electronic features that impart a specific pharmacological character to a particular drug) for the Di-like receptors.

All previous studies involving the compound 2, both in vivo and in vi tro, have used the racemate. Moreover, while (±)-2 is selective for dopamine receptors, it has only about ten-fold selectivity for D₂ vs. D₂ receptors in rat striatum. (See, Brewster, W.K. et al., supra; Mottola, D.M. et al. , in J. Pharmacol . Exp. Ther. 1992, 262, 383-393.) Of particular interest is the unprecedented selectivity of 2 for activating functions mediated by postsynaptic, but not presynaptic, D₂-like receptors. (See, . Mottola, D.M. et al. , supra; also, Mottola, D.M. et al. , in Soc. Neurosci . Abstr. 1991, 17, 818 and Nichols, N.F. et al . , in Soc . Neurosci . Abstr. 1992, 18, 1170.) Mottola and co-workers (1992), supra, based on molecular modeling studies, hypothesized that a particular enantiomer of dihydrexidine, ( 6aR, 12bS) , would be the more active D_x ligand. Again, no work was actually carried out using individual enantiomers, and the authors' hypothesis amounts to no more than speculation. Moreover, in which enantiomer the D₂ activity might lie was, until the present work, very much anyone' s guess.

Thus, knowledge of which enantiomer or enantiomers is responsible for the Ω and D₂ activities of 2 is of critical importance in understanding the intimate aspects of the D_x and D₂ pharmacophore and of neurological processes mediated by dopamine receptors, in general.

Certain substituted phenanthridines are disclosed in International Publication Number WO 92/04356. At page 11, of the disclosure, the specification states the obvious in that a compound having two or more asymmetric carbon atoms exists in diastereomeric forms. Stating that the alleged invention included within its scope all of the isomeric forms of a claimed compound, the specification once against recites a generally accepted proposition. However, on closer examination, the specification does not contain specific disclosures of individual enantiomeric compounds. Moreover, the specification is devoid of any rationale or motivation for performing the resolution of racemic mixtures, let alone include any discussion of a viable means for accomplishing such an operation.

3. Summary of the Invention

Accordingly, the present invention provides the resolution of the enantiomers of 2 and its substituted hexahydrobenzo [a] phenanthridine analogs and discloses pharmacologic evidence that suggests that, quite unexpectedly, -both Ω_λ and D₂ receptor affinities, as well as functional effects, including the unprecedented D₂ postsynaptic selectivity, reside in the (6ai?, 12bS) - (+) - enantiomer of 2 and the corresponding enantiomers of its substituted analogs.

Generally, then, it is an object of the present invention to provide a compound of the formula

and pharmaceutically acceptable salts thereof wherein the H_a and H_b are trans across ring fusion bond c, R is hydrogen or C - C₄ alkyl R is hydrogen or a phenol protecting group X is fluoro, chloro, bromo, iodo, or a group of the formula -OR_ς wherein is hydrogen or a phenol protecting group, provided that when X is a group of the formula -OR₅, the groups R_x and R₅ can be taken together to form a group of the formula -CH₂-; and

R₂, R₃ and R₄ are independently selected from the group consisting of hydrogen, C₁-C₄ alkyl, phenyl, fluoro, chloro, bromo, iodo, or a group -OR_x wherein R is as defined above, provided said compound is optically active. Preferably, the compound is the (+) -isomer, although in other embodiments, the compound is the (-)- isomer. In a particular embodiment of the invention, the groups R₂, R₃, and R₄ are all hydrogen. In another, at least one of the groups R₂, R₃, and R₄.is methyl.

Other objects of the present invention, including compositions comprising the disclosed optically acitve compounds and methods of their use, will be apparent to one of ordinary skill considering the detailed descriptions provided herein.

4. Brief Description of the Figures

Figure 1. Competition of enantiomers of 2 for D_x receptors labeled by ³H-SCH23390. (A) Competition in rat striatal membranes. (B) Competition in membranes prepared from Ltk-cells transfected with human D_λ receptor. (+) -2 had ca. twice the affinity of racemic 2 in both preparations. In the striatal membranes, (-)-2 had significantly less affinity than the racemate or (+) enantiomer.

Figure 2. Stimulation of cAMP synthesis by drugs in rat striatal membranes. ( + ) -2 was nearly 100 fold more potent than the (-) enantiomer in stimulating cAMP synthesis in rat striatal membranes.

Figure 3. Competition of enantiomers of 2 for D₂ receptors in rat striatal membranes labeled by ³H- spiperone. (+)-2 had about twice the affinity of racemic

2, and both the racemate and (+) -enantiomer had significantly greater affinity than the (-) enantiomer.

Figure 4. A schematic illustration is provided for the isolation of the enantiomers of dihydrexidine. In the scheme, the lower case letters for each step denote the following reaction conditions: (a) i. (J?) - Methoxyphenyl acetyl chloride, 20% NaOH (aq) , CH₂C1₂; ii. chromatography; (b) LiEt₃BH, THF; (c) BBr₃, CH₂C1₂.

5. Detailed Description of the Preferred Embodiments 5.1.Resolution of the Enantiomers

Initial attempts to resolve the enantiomers of 2 utilizing classical resolution techniques were ineffective. In particular, it was discovered that neither the tartrate nor the dibenzoyltartrate diastereomeric salts of the ether-protected amine precursor 3 (See, Figure 4) could be separated by crystallization. The attempts using these classical methods were, therefore, abandoned in favor of a different method, described further below.

As depicted in Figure 4, the diastereomeric (J?) -O- ethyl mandelic acid amides of racemic trans-10, 11- dimethoxy-5, 6,6a, 7, 8,12b-hexahydrobenzo[a]phenanthridine 4 were prepared by an adaptation of the procedure of Johansson, A.M. et al. , described in J. Med. Chem. 1987, 30, 602-611. In this procedure, the ether-protected amine 3 was coupled with (J?) -O-methyl mandeloyl chloride to yield the two diastereomeric amides.

The resulting amides were separated by centrifugal chromatography (chromatotron) using 40% ethyl acetate/hexane eluent and a 2 mm silica gel rotor. While the chromatron was used to effect this separation on a small scale, any of a variety of chromatographic techniques would apply on larger scales, such as column chromatography. Crystallization of the individual amides provided the diastereomers in greater than 99% purity, as judged by HPLC analysis. An X-ray quality crystal was obtained for the diastereomer with lower R_f on TLC and the analysis demonstrated that it corresponded to (6aS, 12bi?) -4. Reductive cleavage of the chiral auxiliaries of (6ai?12bS) -4 and (6aS, 12bR) -4 with LiEt₃BH (Super Hydride) in THF (see, Mellin, C. et al. , in J. Med. Chem. 1991, 34 , 497-510) provided the resolved amines ( 6aR, 12bS) - (+) -5 and (6aS,12bJ?) - (-) -5.

The enantiomericallypure catecholamines (6aJ?,12bS) - (+)-2 and (6aS, 12bJ?) - (-) -2 were prepared from the corresponding methoxy precursors by treatment with BBr₃ and crystallized as their hydrochloride salts.

It is important to note that in the reductive cleavage step, the use of Super Hydride is critical because, as applicants have discovered, the chiral auxiliary group is not removed by the usual type of reducing agents, such as lithium aluminum hydride. 5.2.Pharmacology

The enantiomers of 2 were tested for dopaminergic activity using in vi tro biochemical techniques. The results showed that (+) -2 had about twice the affinity of (±) -2 for the D_x receptor in both rat striatal membranes, and in transfected Ltk^" cells. In the striatal membranes, the (-) -enantiomer shows significantly less affinity than either the racemate or (+) -enantiomer. Like racemic 2 or dopamine, (+) -2 causes a doubling of cAMP synthesis in striatal membranes, indicating that

(+) -2 is a full agonist. Conversely, (-)-2 is nearly 100-fold less potent than (+)-2, and does not cause a fully maximal response (relative to dopamine) at the highest concentration tested (5 μM) . In competition for D₂ receptors, (+) -2 exhibits about twice the affinity of

(±)-2, and about 15-fold higher affinity than the (-)- enantiomer. These data indicate that the active enantiomer for both D_x and D₂ receptors is (6aR, 12bS) -

(+)-2. Turning now to the remaining figures, Figure 1 illustrates that, in both rat striatum and Ltk'-hDi cells, (6ai?, 12bS) - (+) -2 had approximately twice the affinity (i.e., IC₅₀ = 5.6 nM) of the racemate (IC₅₀ = 11.6 nM) . The (6aS, 12bJ?;- (-) enantiomer had significantly lower affinity than either (6ai?, 12bS) - (+) -2 or (±) -2 at the D-_ receptor.

The data from the dopamine-sensitive adenylate cyclase assay (see, Table 1, below, and Figure 2) demonstrate that the (6ai?,12bS) -(+) -enantiomer and the racemate are about two orders of magnitude more potent than dopamine, the latter having an EC₅₀ of about 5 μM. Furthermore, ( 6aR, 12bS) - (+) -2 and the racemate both produce a full agonist response of adenylate cyclase. In contrast, the enantiomer (6aS, 12bi?) - (-) -2 is significantly less potent (EC₅₀ = 2.15 mM) in the adenylate cyclase assay and lacks the full efficacy character of the (+) antipode. It is of note that prototypical Dj agonists such as SKF38393 (EC_S0 = 100 nM) and CY208-243 (6, pD₂ = 6.1, whose structure is depicted, below; see, Seiler, M.P. et al. , in J. Med. Chem. 1991, 34 , 303-307) are only partial agonists that cause less than 50% stimulation of adenylate cyclase..

A similar pattern was seen in transfected Ltk^" cells. This finding is of importance because there are no D₂-like receptors in these cells. Thus, actions of enantiomers of 2 at D₂ receptors do not influence adenylate cyclase studies in these membrane preparations, consistent with our earlier findings. (Cook, L.L. et al., in Soc. Neurosci . Abstr. 1991, 17, 606.)

Table 1.

Comparison of Dihydrexidine and its Analogues and Certain Other Dopamine Agonists at D_x and

D₃ Receptors in Rat Striatal Membranes

Adenylate Maximal

D₂ Cyclase Stimulation

Drug Potency* Potency EC₅₀ (nM) of Adenylate IC₅₀ (nM) IC_S0 (nM) Cyclase (% vs . DA)

(±)-2 11.6 ± 132 ± 19 140 nM 95 1.0

(+)-2 5.6 ± 87.7 ± 60 nM 105 1.1 12.2 Adenylate Maximal

D₂ Cyclase Stimulation

Drug Potency* Potency EC₅₀ (nM) of Adenylate IC₅₀ (nM) IC₅₀ (nM) Cyclase (% vs. DA)

(-)-2 149 ± 11 1,250 ± >1000 nd 290

SCH23390 1.01 ± - NA NA 1.0

Domperidone - 2.80 ± NA NA 1.0

NA = not applicable (these compounds are antagonists) .

*A11 tests were performed as described in the Methods section. Hill coefficients for the agonist binding curves were significantly less than 1, and the data thus are expressed as IC_sos since K values cannot be determined until the number of binding sites is resolved. To minimize interassay variability, the values in the tables were from assays in which four or more compounds were run on the same day.

While the data described herein demonstrate that the O_x activity resides in the (6aJ?, 12bS) -(+) -enantiomer, it was also important to determine in which enantiomer the significant D₂ affinity resided. As shown in Figure 3 and Table 1, here again ( 6aR, 12bS) - (+) -2 had about twice the potency of the racemate, with (6aS,12bR) - (-) -2 having significantly lower affinity (87.7, 132, and 1250 nM, respectively) .

Therefore, our data indicate that both receptor recognition and functional efficacy at O receptors reside principally in the (6a!-., 12b-S) - (+) stereoisomer. At D₂ receptors, the binding affinity also is contained in the same isomer. It is anticipated that functional efficacy at the D₂ receptors resides in the (+) - enantiomer, as well.

We have indicated previously that the full efficacy properties of dihydrexidine may be due to the presence of the trans extended conformation of the ethylamine moiety or the near coplanarity of the aromatic rings. Brewster, W.K. et al., in J. Med . Chem . 1990, 33 , 1756-1764 . As a consequence of the results of the present work, the enantioselective conceptual model of the D_x receptor appears to be vastly superior to two-dimensional models in accounting for the biological activity of these compounds.

Remaining to be addressed, however, is the ramification of the D₂-like affinity of dihydrexidine and several of its analogues. Existing models of the pharmacophore for various D₂-like receptors do not, at least at first glance, easily accommodate the pendent phenyl ringof the 10,11-dihydroxybenzo- [a]phenanthridine class of dopamine agonists. Moreover, while dihydrexidine has affinity for D₂-like receptors, recent data indicate that its agonist functional properties appear to be limited to only some subpopulations of these receptors (i.e., those located post-synaptically) . Thus, this drug class may be very useful in understanding ligand interactions with the D₂-like receptor family, and may provide important data for incorporation into molecular modeling studies.

5.3.Pharmaceutical Compositions Comprising the Optically Active Compounds of the Present Invention

As should be apparent, the present invention contemplates compositions comprising the optically active compounds disclosed herein. Preferably, these compositions include pharmaceutical compositions comprising a therapeutically effective amounr of an optically active compound along with a pharmaceutically acceptable carrier.

As used herein, the term "pharmaceutically acceptable" carrier means a non-toxic, inert solid, semi- solid liquid filler, diluent, encapsulating material or formulation auxiliary of any type. Some examples of the materials that can serve as pharmaceutically acceptable carriers are sugars, such as lactose, glucose and sucrose, starches such as corn starch and potato starch, cellulose and its derivatives such as sodium carboxymethyl cellulose, ethyl cellulose and cellulose acetate; powdered tragacanth; malt, gelatin, talc; excipients such as cocoa butter and suppository waxes; oils such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil and soybean oil; glycols, such as propylene glycol, polyols such as glycerin, sorbitol, mannitol and polyethylene glycol; . esters such as ethyl oleate and ethyl laurate, agar; buffering agents such as magnesium hydroxide and aluminum hydroxide; alginic acid; pyrogen-free water; isotonic saline, , Ringer's solution; ethyl alcohol and phosphate buffer solutions, as well as other non-toxic compatible substances used in pharmaceutical formulations. Wetting agents, emulsifiers and lubricants such as sodium lauryl sulfate and magnesium stearate, as well as coloring agents, releasing agents, coating agents, sweetening, flavoring and perfuming agents, preservatives and antioxidants can also be present in the composition, according to the judgement of the formulator. Examples of pharmaceutically acceptable, antioxidants include water soluble antioxidants such as ascorbic acid, cysteine hydrochloride, sodium bisulfite, sodium metabisulfite, sodium sulfite, and the like; oil soluble antioxidants such as ascorbyl palmitate, butylated hydroxyanisole (BHA) , butylated hydroxytoluene (BHT) , lecithin, propyl gallate, aloha-tocopherol and the like: and the metal chelating agents such as citric acid, ethylenediamine tetraacetic acid (EDTA) , sorbitol, tartaric acid, phosphoric acid and the like.

By a "therapeutically effective amount" of an optically active compound, such as a dopaminergic agent, is meant a sufficient amount of the compound to treat neurological or behavior disorders at a reasonable benefit/risk ratio applicable to any medical treatment. It will be understood, however, that the total daily usage of the compounds and compositions of the present invention will be decided by the attending physician within the scope of sound medical judgement. The specific therapeutically effective dose level for any particular patient will depend upon a variety of factors including the disorder being treated and the severity of the disorder; activity of the specific compound employed; the specific composition employed; the age, body weight, general health, sex and diet of the patient; the time of administration, route of administration, and rate of excretion of the specific compound employed; the duration of the treatment; drugs used in combination or coincidently with the specific compound employed; and like factors well known in the medical arts.

The total daily dose of the optically active compounds of the present invention administered to a subject in single or in divided doses can be in amounts, for example, from 0.01 to 25 mg/kg body weight or more usually from 0.1 to 15 mg/kg body weight. Single dose compositions may contain such amounts or submultiples thereof to make up the daily dose. In general, treatment regimens according to the present invention comprise administration to a human or other mammal in need of such treatment from about 1 mg to about 1000 mg of the compound(s) of this invention per day in multiple doses or in a single dose of from 1 mg, 5 mg, 10 mg, 100 mg, 500 mg or 1000 mg.

The compounds of the present invention may be administered alone or in combination or in concurrent therapy with other agents which affect the central or peripheral nervous system.

Liquid dosage forms for oral administration may include pharmaceutically acceptable emulsions, microemulsions, solutions, suspensions, syrups and elixirs containing inert diluents commonly used in the art such as water. Such compositions may also comprise adjuvants, such as wetting agents; emulsifying and suspending agents; sweetening, flavoring and perfuming agents.

Injectable preparations, for example, sterile injectable aqueous or oleaginous suspensions may be formulated according to the known art using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation may also be a sterile injectable solution, suspension or emulsion in a nontoxic parenterally acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water,

Ringer's solution, U.S.P. and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil can be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid are used in the preparation of injectables.

The injectable formulation can be sterilized, for example, by filtration through a bacteria-retaining filter, or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved or dispersed in sterile water or other sterile injectable medium just prior to use.

In order to prolong the effect of a drug, it is often desirable to slow the absorption of a drug from subcutaneous or intramuscular injection. The most common way to accomplish this is to inject a suspension of crystalline or amorphous material with poor water solubility. The rate of absorption of the drug becomes dependent on the rate of dissolution of the drug which is, in turn, dependent on the physical state of the drug, for example, the crystal size and the crystalline form. Another approach to delaying absorption of a is drug to administer the drug as a solution or suspension in oil. Injectable depot forms can also be made by forming microcapsule matrices of drugs and biodegradable polymers such as polylactide-polyglycoside. Depending on the ratio of drug to polymer and the composition of "the polymer, the rate of drug release can be controlled. Examples of other biodegradable polymers include poly- orthoesters and polyanhydrides. The depot injectables can also be made by entrapping the drug in iiposomes or microemulsions which are compatible with body tissues.

Suppositories for rectal administration of the drug can be prepared by mixing the drug with a suitable nonirritating excipient such as cocoa butter and polyethylene glycol which are solid at ordinary temperature but liquid at the rectal temperature and will, therefore, melt in the rectum and release the drug.

Solid dosage forms for oral administration may include capsules, tablets, pills, powders, prills and granules. In such solid dosage forms the active compound may be admixed with at least one inert diluent such as sucrose, lactose or starch. Such dosage forms may also comprise, as is normal practice, additional substances other than inert diluents, e.g., tableting lubricants and other tableting aids such as magnesium stearate and microcrystalline cellulose. In the case of capsules, tablets and pills, the dosage forms may also comprise buffering agents. Tablets and pills can additionally be prepared with enteric coatings and other release- controlling coatings.

Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polyethylene glycols and the like. The active compounds can also be in micro- encapsulated form with one or more excipients as noted above. The solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings and other coatings well known in the pharmaceutical formulating art. They may optionally contain opacifying agents and can also be of a composition that they release the active ingredient (s) only, or preferably, in a certain part of the intestinal tract, optionally in a delayed manner.

Examples of embedding compositions which can be used include polymeric substances and waxes.

Dosage forms for topical or transdermal administration of a compound of this invention further include ointments, pastes, creams, lotions, gels, powders, solutions, sprays, inhalants or patches. The active component is admixed under sterile conditions with a pharmaceutically acceptable carrier and any needed preservatives or buffers as may be required. Ophthalmic formulations, ear drops, eye ointments, powders and solutions are also contemplated as being within the scope of this invention.

The ointments, pastes, creams and gels may contain, in addition to an active compound of this invention, excipients such as animal and vegetable fats, oils, waxes, paraffins, starch, tragacanth, cellulose derivatives, polyethylene glycols, silicones, bentonites, silicic acid, talc and zinc oxide, or mixtures thereof.

Powders and sprays can contain, in addition to the compounds of this invention, excipients such as iactose, talc, silicic acid, aluminum hydroxide, calcium silicates and polyamide powder, or mixtures of these substances. Sprays can additionally contain customary propellants such as chlorofluorohydrocarbons. Transdermal patches have the added advantage of providing controlled delivery of a compound to the. body. Such dosage forms can be made by dissolving or dispersing the compound in the proper medium. Absorption enhancers can also be used to increase the flux of the compound across the skin. The rate can be controlled by either providing a rate controlling membrane or by dispersing the compound in a polymer matrix or gel.

Accordingly, the present invention is useful in the treatment or alleviation of disease, especially those disorders related to a central nervous system dysfunction. Such dysfunctions of the central nervous system may be characterized by an apparent neurological, physiological, psychological, or behavioral disorder, the symptoms of which can be reduced by the administration of an effective amount of the optically active compounds of the present invention.

In particular, the present invention is used in a method of alleviating the effects of Parkinson's disease. A patient can also be treated for a CNS movement-related disorder, including, but not limited to, Huntington's disease, Pick's disease or Creutzfeldt-Jakob disease. Dihydrexidine has also been shown to be a specific renal vasodilator. See, e.g., Kohli, J., in Europ. J. Pharmacol . 1993, 235, 31-35. Hence, the optically active compounds of the present invention can be used in a method of treating or alleviating the effects of a cardiovascular disorder, such as congestive heart failure.

Furthermore, a method of enhancing endocrine function is also contemplated which comprises administering to a patient in need of such enhancement an effective amount of the optically active compounds of the present invention, especially (6aJ2, 12bS) - (+) -10, 11- dihydroxy-5,6, 6a,7, 8,12b-hexahydrobenzo[a]phenanthridine, an O-alkylated or N-alkylated analog thereof, or its pharmaceutically acceptable acid addition salt, such as the hydrochloride. Preferably, such enhancement leads to an increase in endocrine function or secretion.

In a specific embodiment of the invention, a pharmaceutically acceptable antipyschotic composition is provided which comprises an effective amount of the compound (6ai?, 12bS) - {+) -10, ll-dihydroxy-5, 6, 6a, 7, 8, 12b- hexahydrobenzo[a]phenanthri-dine, an O-alkylated or N- alkylated analog thereof, or its pharmaceutically acceptable acid addition salt and a pharmaceutically acceptable carrier.

6. Examples

6.1.Resolution of the Enantiomers of Dihydrexidine Using Methods Applicable to Its Analogs

6.1.1.Materials and Methods Melting points were determined on a Thomas-Hoover

Meltemp apparatus and are uncorrected except where indicated. ^XH NMR spectra were recorded on a Che agnetics 200-MHz or a Varian VXR-500S 500-MHz instrument. Chemical shifts are reported in values (parts per million, pp ) relative to an internal standard of tetramethylsilane in CDC1₃, except where noted. Abbreviations used in NMR analysis are as follows: s, singlet; d, doublet; t, triplet; m, multiplet; dt, doublet of triplets. Analytical thin-layer chromatography (TLC) was performed on Baker-flex silica gel 1B2-F plastic plates. Microanalyses were obtained from the Purdue Microanalytical Laboratory and from Galbraith Laboratories, Inc. The chemical ionization mass spectra (CIMS) were determined on a Finnigan 4000 quadrupole spectrometer using ammonia or isobutane as the reagent gas, as noted, and are reported as m/e (relative intensity) . Optical rotations were obtained on a Perkin- Elmer 241 polarimeter. Solvents and reagents were used as purchased, except as noted. THF was distilled from sodium metal/benzophenone ketyl.

6.1.2.

{6aR, 12bS) - (+) -6- (Λ-α-methoxyphenylacetyl) -10,11- dimethoxy-5, 6, 6a, 7,8, 12b-hexahydrobenzo [a]phen¬ anthridine, (+)-4, and (6aS,12bfi) - (-) -6- (JZ-α-meth- oxyphenylacetyl) -10,ll-dimethoxy-5,6,6a,7,8,12b- hexahydrobenzo[a]phenanthridine, (-) -4

R- {-) -Methoxyphenylacetic acid (31 mg, 0.19 mmol; [α]²⁵-154 degrees; Aldrich Chemical Co.) was added to a 10 mL round bottom flask containing thionyl chloride (0.5 mL) . After stirring for 2 h at 25 °C, the volatiles were removed. Residual thionyl chloride was removed azeotropically by the codistillation of benzene to provide R- (-) -O-methyl mandeloyl chloride. This residue was dissolved in 1 mL of dichloromethane. Racemic 10,11- dimethoxy-5, 6,6a, 7, 8,12b-hexahydrobenzo[a]phenan-thridine hydrochloride (50 mg, 0.15 mmol) was dissolved in water (1 mL) and dichloromethane (1 mL) . After the salt had dissolved, 1 N NaOH (0.5 mL) was added, followed by addition of the dichloromethane solution of the mandeloyl chloride.

When TLC analysis (5% methanol/dichloromethane, NH₃ atmosphere) indicated that all of the amine had been consumed, the layers were separated, and the aqueous layer was extracted with dichloromethane (3 x 5 mL) . The pooled dichloromethane fractions were washed sequentially with saturated aqueous sodium carbonate solution (10 mL) , 5% HC1 (2 x 5 mL) and brine. After drying over MgS0₄, the dichloromethane solution was filtered and the solvent was removed by rotary evaporation.

The residual oil was then separated into its components using a Chromatotron (Harrison Research, Palo Alto, CA) by elution on a 1 mm silica gel rotor with 40% ethyl acetate/hexane. The two major fractions were collected and concentrated by rotary evaporation. The faster moving component was crystallized from hexane to provide 16 mg (24%), mp 147-149 °C; [α] _D -97.45 degrees

(c 0.25, EtOH) ; CIMS (isobutane) : M+l, 444; ^XH NMR δ 7.45

(d, 1, ArH, J = 7.6 Hz) , 7.38 (m, 2, ArH) , 7.33 (m, 3,

ArH) , 7.21 ( , 1, ArH), 7.00 (s, 1, ArH), 6.97 (t, 1, ArH, J = 7.4 Hz) , 6.72 (s, 1, ArH) , 6.21 (d, 1, ArCH, J

= 7.41 Hz), 5.15 (s, 1, ArCHO) , 4.90 (d, 1, ArCH, J =

14.7 Hz) , 4.28 (d, 1, ArCH, J = 14.7 Hz), 4.20 (d, 1,

Ar₂CH, J - 12.6 Hz) , 3.91 (s, 3, OCH₃) , 3.83 (s, 3, OCH₃) ,

3.65 (s, 3, OCH₃) , 3.61 (m, 1, CHN) , 3.11 (m, 1, CHAr) , 2.90 (m, 1, CHAr) , 2.78 (m, 1, CHCN) , 1.66 (m, 1, CHCN) .

Anal. (C₂₅H₂₃N0₂) Cal'd (Obs'd) : C, 75.81 (75.48); H, 6.59 (6.51) ; N, 3.16 (3.16) .

The slower running component was isolated and crystallized from ethyl acetate to provide the other diastereomer (20 mg, 30%) , mp 171-172 °C; [α] _D +155.91 degrees (c 0.25, EtOH) ; CIMS (isobutane) : M+l, 444; *H NMR δ 1.AS (d, 1, ArH, J = 7.69 Hz) , 7.44-7.35 (m, 6, ArH) , 7.09 (t, 1, ArH), 6.72 (s, 1, ArH), 7.01 (s, 1, ArH) , 6.69 (d, 1, ArCH, J^" = 6.78 Hz), 5.04 (s, 1, ArCHO), 4.86 (d, 1, ArCH, J = 14.4 Hz), 4.17 (d, 2, Ar₂CH, ArCH) ,

3.90 (s, 3, OCH₃) , 3.83 (s, 3, OCH₃) , 3.60 (m, 1, CHN) , 3.41 (s, 3, OCH₃) , 3.11 (m, 1, CHAr), 2.92 (m, 1, CHAr) , 2.78 (m, 1, CHCN) , 1.66 (m, 1, CHCN) . Anal. (C_2SH₂₃N0₂) Cal'd (Obs'd) : C, 75.81 (75.42) ; H, 6.59 (6.73) ; N, 3.16 (3.08) .

6.1.3.

(6aJ.,12bS) - (+) -10, 11-dimethoxy-5, 6, 6a, 7, 8, 12b- hexahy-drobenzo[a]phenanthridine hydrochloride, (+)-5 The (+) - (6aR,12bS) O-methylmandeloylamide 4 (435 mg,

0.982 mmol) was dissolved in 25 mL of dry THF under nitrogen. The solution was cooled to 0 °C and then 6 mL of a 1.0 M solution of LiEt₃BH in THF was added slowly via syringe. The solution was stirred at 0 °C for 12 h. The solution was poured into 25 mL of ice-cooled 1.0 M

HCl . The aqueous layer was washed with 2 x 20 mL ether and then made alkaline with NH₃. The resulting free base was isolated by extraction with 3 x 30 mL of dichloromethane. The combined organic extracts were dried (MgS0₄) , filtered and concentrated in vacuo.

The HCl salt was formed with acidic ethanol and the product was crystallized from acetonitrile to afford 217 mg (67%) mp 232-234 °C; [α]_D +106 degrees (c 0.75, EtOH); CIMS (isobutane) : M+l, 296; ^XH NMR (d₆ DMSO) δ 9.65 (s, 2, NH₂ ⁺) , 7.44-7.32 (m, 4, ArH), 6.86 (s, 2, ArH), 4.37(d, 2, ArCH₂N, J= 4.12 Hz), 4.23 (d, 1, Ar₂CH, J = 11.07 Hz), 3.75 (S, 3, OCH₃) , 3.68 (s, 3, 0CH₃) , 3.00-2.94 (ddd, 1, CHN), 2.86-2.79 (m, 2, ArCH₂) , 2.22- 2.15 (m, 1, CHCN), 1.98-1.89 (m, 1, CHCN) . Anal. (C₁₉H₂₂C1N0₂) Cal'd (Obs'd) : C, 68.85 (68.79); H, 6.70 (6.71) ; N, 4.23 (4.24) .

6.1.4.

(6a£,12bi.) - (-) -10,ll-dimethoxy-5,6,6a,7,8,12b-hexa- hydrobenzo [a ] henanthridine hydrochloride , ( - ) - 5

Following an identical procedure to that for (+)-5, the (-) - (6aS, 12bi?) -0-methyl mandeloyl amide 4 (344 mg,

0.777 mmol) gave 173 mg (66%) of the hydrochloride following crystallization from acetonitrile; mp 230-232

°C; [α]_D -107 degrees (c 0.75, EtOH); CIMS (isobutane) :

M+l, 296; ^XH NMR (d₆ DMSO) δ 9.62 (s, 2, NH₂ ⁺) , 7.42-7.32

(m, 4, ArH), 6.86 (s, 2, ArH), 4.37 (d, 2, ArCH₂N, J =

4.12 Hz), 4.23 (d, 1, Ar₂CH, J = 11.08 Hz), 3.75 (s, 3,

OCH₃) , 3.68 (s, 3, OCH₃) , 3.00-2.93 (dt, 1, CHN), 2.88-

2.76 (m, 2, ArCH₂) , 2.22-2.15 (m, 1, CHCN), 1.98-1.89 (m,

1, CHCN) . Anal. (C₁₉H₂₂C1N0₂) Cal'd (Obs'd) : C, 68.85

(68.82) ; H, 6.70 (6.66) ; N, 4.23 (4.18) .

6.1.5.

(6aJ2,12bS) - ( + ) -10 , ll-dihydroxy-5, 6 , 6a, 7 , 8 , 12b- hexahy-drobenzo [a] phenanthridine hydrochloride,

( + )-2

The hydrochloride salt of (+)-5 (217 mg, 0.655 mmol) was dissolved in water and converted to the free base with cone. NH₄OH. The free base was extracted into 3 x 25 mL of dichloromethane, the organic solution was dried over MgS0₄, filtered, and concentrated to a clear oil using rotary evaporation. The residue was dissolved in 20 mL of dichloromethane and the solution was cooled to -

78 °C. A 1.0 M solution of BBr₃ in CH₂C1₂ (3 mL, 3 mmol) was added slowly to the solution of the free base via syringe under nitrogen over 30 min. The solution was left to warm to room temperature and was stirred overnight. The reaction was quenched by the addition of

5 mL of methanol. The solvent was removed via rotary evaporation and the flask was left under high vacuum for 8 h. The residue was dissolved in water and the pH was adjusted to 9-10 with a saturated solution of sodium bicarbonate under nitrogen. The precipitated free base was isolated by suction filtration, washed on the filter with cold water and dried under vacuum. The filtrate was extracted with 3 x 25 mL of dichloromethane. The dichloromethane extracts were dried (MgS0₄) filtered and concentrated on the rotary evaporator. This residue and the solid product were combined and dissolved in ethanol. The solution was acidified with ethanolic HCl and the volatiles were removed in vacuo. The HCl salt was isolated following crystallization fromEtOAc/isopropanol to yield 158 mg (79%), mp dec >120 °C; [a] _D +83 degrees

(c 0.25, EtOH); CIMS (isobutane) : M+l, 268; ^XH NMR (d₆ DMSO) δ 9.62 (s, 2, NIT), 8.87, 8.85 (2s 2, OH), 7.43- 7.37 (m, 3, ArH), 7.34 (m, 1, ArH), 6.70 (s, 1, ArH), 6.61 (s, 1, ArH), 4.35 (d, 2, ArCH₂N, J=3.94 Hz), 4.13 (d, 1, Ar₂CH, J^" = 11.26 Hz) , 2.97-2.90 (m, 1, CHN), 2.78-

2.72 (m, 1, ArCH₂) , 2.72-2.64 (m, 1, ArCH₂) , 2.18-2.11 (m, 1, CHCN), 1.93-1.84 (m, 1, CHCN); HRMS (CI, isobutane) Calculated for C₁₇H₁₈C1N0₂ 268.1338, Found 268.1332. 6.1.6.

(6aS,12tR)-(-)-IW,n-<3dl5drCT*y-5,6,6a,7,8,:L2 ^ ridine hydrochloride, (-)-2

Following a procedure identical to that for (+)-2,

404 mg (1.219 mmol) of (-)-5 hydrochloride was converted to 351 mg (94%) of the HCl salt following crystallization from EtOAc/isopropanol; mp dec >120 °C; [cκ]_D -86 degrees

(c 0.25, EtOH) ; CIMS (isobutane) : M+l, 268; *H NMR (d₆

DMSO) δ 9.61 (s, 2, NH₂ ⁺) , 8.87, 8.85 (2s, 2, OH) , 7.43-

7.37 (m, 3, ArH), 7.34 (m, 1, ArH), 6.70 (s, 1, ArH),

6.61 (s, 1, ArH) , 4.35 (d, 2, ArCH₂N, J = 3.11 Hz), 4.13

(d, 1, Ar₂CH, J = 10.98 Hz), 2.97-2.90 (m, 1, CHN) 2.78-

2.72 (m, 1, ArCH₂) , 2.72-2.64 (m, 1, ArCH₂) , 2.18-2.11

(m, 1, CHCN), 1.93-1.84 (m, 1, CHCN); HRMS (CI, isobutane) Calculated for C₁₇H₁₈C1N0₂ 268.1338, Found

268.1332.

6.1.7.

X-ray Crystallography of (6aS,12b) - (-) -N-Λ-methoxy- phenylacetyl-10, ll-dimethoxy-5, 6, 7, 8, 6a, 12b- hexahydrobenzo[a] henanthri-dine [ (-) -4) ]

The absolute configuration of this compound was clearly established on the basis of the known (R) - stereochemistry of the O-methylmandelic acid used to prepare (-) -4.

Crystal data: C_2βH₂₉N0₄; formula weight = 443.55; orthorhombic; space group P2₁2₁2₁ (No. 19); Z = A ; a = 8.8868 (6) A, b = 12.027 (4) A, c = 21.940 (2) A, V = 2344 (1) A³; calculated density = 1.26 g/cm³; absorption coefficient = 0.78 cm^*1. Intensity data were collected at 20 °C, with Mo Kα radiation (λ = 0.71073 A) on an Enraf-Nonius CAD4 computer controlled kappa axis diffractometer equipped with a graphite crystal, incident beam monochromator. Data were collected using the - 2 (theta) scan technique. The scan rate varied from 1 to 20 degrees/min (in omega) . The variable scan rate allows rapid data collection for intense reflections where a fast scan rate is used and assures good counting statistics for weak reflections where a slow scan rate is used. Data were collected to a maximum 2 (theta) of 55.0 degrees. The scan range (in deg) was determined as a function of theta to correct for the separation of the Ka doublet (see, CAD4 Operations Manual, Enraf-Nonius,

Delft, 1977) . The scan width was calculated as follows: ω scan width = 0.56 + 0.350 tan(theta) . Moving-crystal moving-counter background counts were made by scanning an additional 25% above and below this range. Thus, the ratio of peak counting time to background counting time was 2:1. The counter aperture was also adjusted as a function of theta. The horizontal aperture width ranged from 1.9 to 2.4 mm; the vertical aperture was set at 4.0 mm. The diameter of the incident beam collimator was 0.7 mm and the crystal to detector distance was 21 cm. For intense reflections an attenuator was automatically inserted in front of the detector; the attenuator factor was 12.9.

A total of 3076 reflections were collected, of which 3076 were unique and not systematically absent. Lorentz and polarization corrections were applied to the data. The linear absorption coefficient is 0.8/cm for Mo Kα radiation. No absorption correction was made. The structure was solved using SHELX-86 (G.M. Sheldrick, Institut fϋr Anorganische Chemie der Universitat

Gottingen, F.R.G.) . The remaining atoms were located in succeeding difference Fourier syntheses. Hydrogen atoms were located and added to the structure factor calculations but their positions were not refined. The structure was refined in full-matrix least squares where the function minimized was Σw(|F₀j - JF_c| ) ² and the weight w is defined as per the Killean and Lawrence method with terms of 0.020 and 1.0. (Killean, R.C.G. and Lawrence, J.L., in Acta Cryst . , Sec. B . 1969, 25, 1750-1752.) Scattering factors were taken from Cromer and Waber.

(Cromer, D.T. and Waber, J.T. International Tables for X-Ray Crystallography; The Kynoch Press: Birmingham, England, 1974; Vol. IV, Table 2.2B.) Anomalous dispersion effects were included in F_c (see, Ibers, J.A. and Hamilton, W.C., in Acta Cryst . , 1964, 17, 781-782); the values for df ' and δf' ' were those of Cromer. (Cromer, D.T. ; Waber, J.T., International Tables for X- Ray Crystallography; The Kynoch Press: Birmingham, England, 1974; Vol. IV, Table 2.3.1.) .

Only the 1609 reflections having intensities greater than 3.0 times their standard deviation were used in the refinements. The final cycle of refinement included 298 variable parameters and converged (largest parameter shift was 0.14 times its esd) with unweighted and weighted agreement factors of: Rl = ∑|F₀ - F_cj/ΣF₀ = 0.056; R2 = SQRT(Σw(F₀ - F₀)²/∑F_o ²) = 0.065.

The standard deviation of an observation unit weight was 1.59. There were no correlation coefficients greater than 0.50. The highest peak in the final difference Fourier had a height of 0.21 e/A³ with an estimated error based on 3F (see, Cruickshank, D.W.J., in Acta Cryst . 1949, 2, 154-157) of 0.04. Plots of Σw(|F₀| - |F_c| )² versus |F₀J, reflection order in data collection, sin theta/lambda, and various classes of indices showed no unusual trends. All calculations were performed on a VAX computer using SDP/VAS. (Frenz, B.A. , in Computing in Crystallography, Schenk, H.; Olthof-Hazelkamp, R. ; van Konigsveld, H.; Bassi, G.C.; Eds.; Delft University Press: Delft, Holland, 1978; pp 64-71.)

6.2.

Synthesis of Substituted Dihydrexidine Analogs

The C-2, C-3, and/or C-4-substituted hexahydroben- zo [a]phenanthridine compounds of the general formula, below,

and pharmaceutically acceptable salts thereof, can also be separated into their component enantiomers by the methods described above, wherein H_a and H_b are trans across ring fusion bond c; R is hydrogen or alkyl; Ri is hydrogen or a phenol protecting group; X is fluoro, chloro, bromo, or iodo, or a group of the formula -OR₅, wherein R₅ is hydrogen or a phenol protecting group, provided that when X is a group of the formula -OR₅, the groups R_λ and R₅ can be taken together to form a -CH₂- group, thus representing a methylenedioxy functional group bridging the C-10 and C-ll positions on the hexahydrobenzo- [a]phenanthridine ring system (as labeled in the formula above) ; and R₂, R₃, and R₄ are independently selected from the group consisting of hydrogen, Ci-C₄ alkyl, phenyl, fluoro, chloro, bromo, iodo, or a group -ORi wherein R_x is as defined above, provided that at least one of R₂, R₃, and R₄ are other than hydrogen. The term "C₁-C₄ alkyl" as used herein refers to branched or straight chain alkyl groups comprising one to four carbon atoms, including, but not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, t- butyl and cyclopropylmethyl.

The term "C₁-C₄ alkoxy" as used herein refers to branched or straight chain alkyl groups comprising one to four carbon atoms bonded through an oxygen atom, including, but not limited to, methoxy, ethoxy and t- butoxy.

2.1.

2- (N-benzyl-N-4-methylbenzoyl) -6,7-dimethoxy-3,4- dihy-dro-2-naphthylamine

To a solution of 4.015 g (19.5 mmol) of 6,7- dimethoxy-β-tetralone in 100 mL of toluene was added 2.139 g (1.025 equiv.) of benzylamine. The reaction was heated at reflux overnight under N₂ with continuous water removal. The reaction was cooled and the solvent was removed by rotary vacuum evaporation to yield the crude N-benzyl enamine as a brown oil.

Meanwhile, the 4-methylbenzoyl chloride acylating agent was prepared by suspending 3.314 g (24.3 mmol) of p-toluic acid in 200 mL benzene. To this solution was added 2.0 equiv. (4.25 mL) of oxalyl chloride, dropwise via a pressure-equalizing dropping funnel at 0 °C. DMF (2-3 drops) was added to the reaction mixture catalytically and the ice bath was removed. The progress of the reaction was monitored via infrared spectroscopy. The solvent was removed by rotary vacuum evaporation and the residual oil was pumped down under high vacuum overnight.

The crude N-benzyl enamine residue was dissolved in 100 mL of CH₂C1₂, and to this solution was added 2.02 g (19.96 mmol) of triethylamine at 0 °C. 4-methylbenzoyl chloride (3.087 g, 19.96 mmol) was dissolved in 20 mL CH₂C1₂ and this solution was added dropwise to the cold, stirring N-benzyl enamine solution. The reaction was allowed to warm to room temperature and was left to stir under N₂ overnight. The reaction mixture was washed successively with 2 x 30 mL of 5% aqueous HCl, 2 x 30 mL of saturated sodium bicarbonate solution, saturated NaCl solution, and was dried over MgS0₄. After filtration, the filtrate was concentrated under vacuum. Crystallization from diethyl ether gave 5.575 g (69.3%) of the enamide mp 96-98 °C. CIMS (isobutane) ; M + 1 414; Η-NMR (CDC1₃) δ 7.59 (d, 2, ArH) , 7.46 ( , 3, ArH) , 7.35 (m, 3, ArH), 7.20 (d, 2, ArH) , 6.60 (s, 1, ArH) , 6.45 (s, 1, ArH) , 6.18 (s, 1, ARCH) , 5.01 (s, 2, ArCH₂N) , 3.80 (s, 3, OCH₃) , 3.78 (s, 3, 0CH₃) , 2.53 (t, 2, ArCH₂) , 2.37 (s,

3, ArCH₃) , 2.16 (t, 2, CH₂) ; Anal. (C₂₇H₂₇N0₃) C, H, N.

2.2.

Trans-2-methyl-6-benzyl-10,11-dimethoxy-5,6,6a,7,8,

12b-hexahydrobenzo[a] henanthridine-5-one A solution of 4.80 g (1 1.62 mmol) of the 6,7- dimethoxy enamide prepared above, in 500 mL of THF, was introduced to an Ace Glass 500 mL photochemical reactor. This solution was stirred while irradiating for 2 hours with a 450 watt Hanovia medium pressure, quartz, mercury- vapor lamp seated in a water cooled, quartz immersion well. The solution was concentrated in vacuo and crystallized from diethyl ether to provide 2.433 (50.7 %) of the 10, 11-dimethoxy lactam, mp 183-195 °C. CIMS

(isobutane) ; M + l 414; ^XH-NMR (CDC1₃) δ 8.13 (d, 1, ArH), 7.30 (s, 1, ArH), 7.23 (m, 6, ArH), 6.93 (s, 1,

ArH) , 6.63 (s, 1, ArH) , 5.38 (d, 1, ArCH₂N) , 5.30 (d, 1, ArCH₂N) , 4.34 (d, 1, Ar2CH, J = 11.4 Hz) , 3.89 (s, 3, OCH₃) , 3.88 (s, 3, OCH₃) , 3.76 (m, 1, CHN) , 2.68 ( , 2, ArCH₂) , 2.37 (s, 3, ArCH₃) , 2.25 (m, 1, CH₂CN) , 1.75 (m, 1, CH₂CN) ; Anal. (C₂₇H₂₇N0₃) C, H, N.

2.3.

Trans-2-methyl-6-benzyl-10,11-dimethoxy-5, ,6a,7,8,

12b-hexahydrobenzo[a] henanthridine hydrochloride

A solution of 1.349 g (3.27 mmol) of the lactam prepared above, in 100 L dry THF was cooled in an ice- salt bath and 4.0 equiv. (13.0 mL) of 1.0 molar BH3 was added via syringe. The reaction was heated as reflux under nitrogen overnight. Methanol (10 mL) was added dropwise to the reaction mixture and reflux was continued for 1 hour. The solvent was removed by rotary vacuum evaporation. The residue was chased two times with methanol and twice with ethanol. The flask was placed under high vacuum (0.05 mm Hg) overnight. The residue was dissolved in ethanol and was carefully acidified with concentrated HCl. The violatiles were removed and the product was crystallized from ethanol to afford 1.123 g

(78.9%) of the hydrochloride salt, mp 220-223 °C. CIMS

(isobutane); M + l 400; ^XH-NMR (CDC1₃, free base) δ 7.37

(d, 2, ArH), 7.33 (m, 2, ArH), 7.26 (m, 1, ArH), 7.22 (s,

1, ArH), 7.02 (d, 1, ArH), 6.98 (d, 1, ArH), 6.89 (s, 1,

ArH), 6.72 (s, 1, ArH), 4.02 (d, 1, Ar₂CH, J = 10.81 Hz),

3.88 (s, 3, 0CH₃) , 3.86 (d, 1, ArCH₂N) , 3.82 (m, 1,

ArCH₂N) , 3.78 (s, 3, OCH₃) , 3.50 (d, 1, ArCH₂N) , 3.30 (d,

1, ArCH₂N) , 2.87 (m, 1, ArCH₂) , 2.82 (m, 1, CHN), 2.34

(m, 1, CH₂CN) , 2.32 (s, 3, ArCH₃) , 2.20 (m, 1, ArCH₂) ,

1.93 (m, 1, CH₂CN) ; Anal. (C₂₇H₂₉N0₂)C, H, N.

2.4.

Trans-2-methyl-10, 11-dimethoxy-5, 6, 6a, 7,8, 12b- hexahy-drobenzo[a] henanthridine hydrochloride

A solution of 0.760 g (1.75 mmol) of the 6-benzyl hydrochloride salt prepared above in 100 mL of 95% ethanol containing 150 mg of 10% Pd/C catalyst was shaken at room temperature under 50 psig of H₂ for 8 hours.

After removal of the catalyst by filtration through

Celite, the solution was concentrated to dryness under vacuum and the residue was recrystallized from acetonitrile to afford 0.520 g (86.2%) of the crystalline salt, mp 238-239 °C. CIMS (isobutane); M + l 310; ¹HNMR

(DMSO, HCl salt) δ 10.04 (s, 1, NH) , 7.29 (d, 1, ArH),

7.16 (m, 2, ArH), 6.88 (s, 1, ArH), 6.84 (s, 1, ArH),

4.31 (s, 2, ArCH₂N) , 4.23 (d, 1, Ar₂CH, J = 10. 8 Hz) ,

3.76 (s, 3, OCH₃) , 3.70 (s, 3, 0CH₃) , 2.91 (m, 2, ArCH₂) ,

2.80 (m, 1, CHN), 2.49 (s, 3, ArCH₂) , 2.30 (m, 1, CH₂CN) ,

2.09 (m, 1, CH₂CN) ; Anal. (C₂₀H₂₃NO₂) C, H, N. 2 . 5 .

Trans-2-methyl-10, ll-dihydroxy-5, 6, 6a, 7, 8, 12b- hexahy-drobenzo[a] henanthridine hydrochloride

0.394 g (1.140 mmol) of the 0,0-dimethyl hydrochloride salt prepared above was converted to its free base. The free base was dissolved in 35 mL of dichloromethane and the solution was cooled to -78 °C.

4.0 equiv. (4.56 mL) of a 1.0 molar solution of BBr₃ was added slowly via syringe. The reaction was stirred under N₂ overnight with concomitant warming to room temperature. 7.0 mL of methanol was added to the reaction mixture and the solvent was removed by rotary vacuum evaporation. The flask was placed under high vacuum (0.05 mm Hg) overnight. The residue was dissolved in water and was carefully neutralized to its free base initially with sodium bicarbonate and finally with ammonium hydroxide (1-2 drops) . The free base was isolated by suction filtration and was washed with cold water. The filtrate was extracted several times with dichloromethane and the organic extracts were dried, filtered and concentrated. The filter cake and the organic residue were combined, dissolved in ethanol and carefully acidified with concentrated HCl . After removal of the volatiles, the HCl salt was crystallized as a solvate from methanol in a yield of 0.185 g (51 %) , mp

(decomposes @ 190 °C) . CIMS (isobutane) ; M + l 282; ¹H-

NMR (DMSO, HCl salt) δ 9.52 (s, 1, NH) , 8.87 (d, 2, OH) ,

7.27 (d, 1, ArH) , 7.20 (s, 1, ArH) , 7.15 (d, 1, ArH),

6.72 (s, 1, ArH) , 6.60 (s, 1, ArH), 4.32 (s, 2, ArCH₂N) , 4.10 (d, 1, ArCH₂CH, J = 11.26 Hz), 2.90 (m, 1, CHN) ,

2.70 (m, 2, ArCH₂) , 2.32 (s, 3, ArCH₃) , 2.13 (m, 1, CH₂CN) , 1.88 (m, 1, CH₂CN) ; Anal. (C₁₈H₁₉N0₂) C, H, N. 2 . 6 .

2-(N-benzyl-N-3-methylbenzoyl)-6,7-dimethoxy-3,4-dihy-dro-2- naphthylamine

To a solution of 3.504 g (17.0 mmol) of 6,7-dimethoxy-β-- tetralone in 100 mL of toluene was added 1.870 g (1.025 equiv.) of benzylamine. The reaction was heated at reflux overnight under N₂ with continuous water removal. The reaction was cooled and the solvent was removed by rotary vacuum evaporation to yield the crude N-benzyl enamine as a brown oil.

Meanwhile, the 3-methylbenzoyl chloride acylating agent was prepared by suspending 3.016 g (22.0 mmol) of jn-toluic acid in 100 mL benzene. To this solution was added 2.0 equiv. (3.84 mL) of oxalyl chloride, dropwise via a pressure-equalizing dropping funnel at 0 °C. DMF (2-3 drops) was added to the reaction mixture catalytically and the ice bath was removed. The progress of the reaction was monitored via infrared spectroscopy. The solvent was removed by rotary vacuum evaporation and the residual oil was pumped down under high vacuum overnight.

The crude N-benzyl enamine residue was dissolved in 100 mL of CH₂C1₂, and to this solution was added 1.763 g (17.42 mmol) of triethylamine at 0 °C. 3-methylbenzoyl chloride (2.759 g, 17.84 mmol) was dissolved in 20 mL CH₂Cl₂ and this solution was added dropwise to the cold, stirring N-benzyl enamine solution. The reaction was allowed to warm to room temperature and was left to stir under N₂ overnight. The reaction mixture was washed successively with 2 x 30 mL of 5% aqueous HCl, 2 x 30 mL of saturated sodium bicarbonate solution, saturated NaCl solution, and was dried over MgS0₄. After filtration, the filtrate was concentrated under vacuum. Crystallization from diethyl ether gave 4.431 g (63.1%) of the enamide mp 96-97 °C. CIMS (isobutane); M + l 414; Η- R (CDCI₃) δ 7.36 (s, 1, ArH), 7.26 (m, 3, ArH), 7.20 (m, 5, ArH), 6.50 (s, 1, ArH), 6.40 (s, 1, ArH), 6.05 (s, 1, ArCH) , 4.95 (s, 2, ArCH₂N) , 3.75 (s, 3, OCH₃) , 3.74 (s, 3, OCH₃) , 2.43 (t, 2, ArCH₂) , 2.28 (s, 3, ArCH₃) , 2.07 (t, 2, CH₂) ; Anal. (C₂₇H₂₇N0₃) C, H, N.

2.7. Trans-3-methyl-6-benzyl-10,11-dimethoxy-5,6,6a,7,8,

12b-hexahydrobenzo[a] henanthridine-5-one

A solution of 1.922 g (4.65 mmol) of the 6,7- dimethoxy enamide prepared above, in 500 mL of THF, was introduced to an Ace Glass 500 mL photochemical reactor. This solution was stirred while irradiating for 5 hours with a 450 watt Hanovia medium pressure, quartz, mercury- vapor lamp seated in a water cooled, quartz immersion well. The solution was concentrated in vacuo and crystallized from diethyl ether to provide 0.835 g (43.4%) of the 10, 11 dimethoxy lactam, mp 154-157 °C.

CIMS (isobutane); M + l 414; -NMR (CDC1₃) δ 7.94 (s, 1, ArH), 7.34 (d, 1, ArH), 7.17 (m, 6, ArH), 6.84 (s, 1, ArH), 6.54 (s, 1, ArH), 5.28 (d, 1, ArCH₂N), 4.66 (d, 1, ArCH₂N) , 4.23 (d, 1, Ar₂CH, J = 11.4 Hz), 3.78 (s, 3, 0CH₃) , 3.74 (s, 3, OCH₃) , 3.61 (m, 1, CHN), 2.59 (m, 2,

ArCH₂) , 2.34 (s, 3, ArCH₃) , 2.15 (m, 1, CH₂CN) , 1.63 (m, 1, CH₂CN) ; Anal. (C₂₇H₂₇N0₃) C, H, N.

2.8.

Trans-3-methyl-6-benzyl-10,11-dimethoxy-5,6,6a,7,8, 12b-hexahydrobenzo[a]phenanthridinehydrochloride

A solution of 0.773 g (1.872 mmol) of the lactam prepared above, in 50 mL dry THF was cooled in an ice- salt bath and 4.0 equiv. (7.5 mL) of 1.0 molar BH₃ was added via syringe. The reaction was heated as reflux under nitrogen overnight. Methanol (6 mL) was added dropwise to the reaction mixture and reflux was continued for 1 hour. The solvent was removed by rotary vacuum evaporation. The residue was chased two times with methanol and twice with ethanol. The flask was placed under high vacuum (0.05 mm Hg) overnight. The residue was dissolved in ethanol and was carefully acidified with concentrated HCl. The violatiles were removed and the product was crystallized from ethanol to afford 0.652 g

(80%) of the hydrochloride salt, mp 193-195 °C. CIMS

(isobutane); M + l 400; ^XH-NMR (CDCl₃, free base) δ 7.38

(d, 2, ArH), 7.33 (m, 2, ArH), 7.28 (m, 2, ArH), 7.07 (d,

1, ArH), 6.90 (s, 1, ArH), 6.88 (s, 1, ArH), 6.72 (s, 1,

ArH), 4.02 (d, 1, Ar₂CH, J = 11.2 Hz), 3.90 (d, 1,

ArCH₂N) , 3.87 (s, 3, OCH₃) , 3.82 (m, 1, ArCH₂N) , 3.78 (s,

3, OCH₃) , 3.48 (d, 1, ArCH₂N) , 3.30 (d, 1, ArCH₂N) , 2.88

(m, 1, ArCH₂) , 2.82 (m, 1, CHN), 2.36 (m, 1, CH₂CN) , 2.32

(s, 3, ArCH₃) , 2.20 (m, 1, ArCH₂) , 1.95 (m, 1, CH₂CN) ;

Anal. (C₂₇H₂₉N0₂) C, H, N.

2.9.

Trans-3-methyl-10,11-dimethoxy-5,6,6a,7, 8,12b- hexahy-drobenzo[a]phenanthridine hydrochloride

A solution of 0.643 g (1.47 mmol) of the 6-benzyl hydrochloride salt prepared above in 100 mL of 95% ethanol containing 130 mg of 10% Pd/C catalyst was shaken at room temperature under 50 psig of H₂ for 8 hours.

After removal of the catalyst by filtration through

Celite, the solution was concentrated to dryness under vacuum and the residue was recrystallized from acetonitrile to afford 0.397 g (78%) of the crystalline salt, mp 254-256 °C. CIMS (isobutane); M + l 310; ¹HNMR

(DMSO, HCl salt) δ 10.01 (s, 1, NH) , 7.36 (d, 1, ArH),

7.09 (d, 1, ArH), 6.98 (s, 1, ArH), 6.92 (s, 1, ArH),

6.74 (s, 1, ArH), 4.04 (s, 2, ArCH₂N) , 3.88 (s, 3, OCH₃) ,

3.81 (s, 3, OCH₃) , 3.76 (d, 1, Ar₂CH) , 2.89 (m, 2, ArCH₂) ,

2.70 (m, 1, CHN), 2.36 (s, 3, ArCH₃) , 2.16 (m, 1, CH₂CN) ,

1.70 (m, 1, CH₂CN) ; Anal. (C₂₀H₂₃NO₂) C, H, N. 2 . 10 .

Trans-3-methyl-10, ll-dihydroxy-5, 6, 6a,7, 8, 12b- hexahydrobenzo[a]phenanthridine hydrochloride

0.520 g (1.51 mmol) of the 0,0-dimethyl hydrochloride salt prepared above was converted to its free base. The free base was dissolved in 35 mL of dichloromethane and the solution was cooled to -78 °C.

4.0 equiv. (6.52 mL) of a 1.0 molar solution of BBr₃ was added slowly via syringe. The reaction was stirred under N₂ overnight with concomitant warming to room temperature. 7.0 mL of methanol was added to the reaction mixture and the solvent was removed by rotary vacuum evaporation. The flask was placed under high vacuum (0.05 mm Hg) overnight. The residue was dissolved in water and was carefully neutralized to its free base initially with sodium bicarbonate and finally with ammonium hydroxide (1-2 drops) . The free base was isolated by suction filtration and was washed with cold water. The filtrate was extracted several times with dichloromethane and the organic extracts were dried, filtered and concentrated. The filter cake and the organic residue were combined, dissolved in ethanol and carefully acidified with concentrated HCl. After removal of the volatiles, the HCl salt was crystallized as a solvate from methanol in a yield of 0.341 g (71.3%), mp

(decomposes @ 190 °C) . CIMS (isobutane); M + l 282; ^XH-

NMR (DMSO, HCl salt) δ 9.55 (s, 1, NH) , 8.85 (d, 2, OH),

7.30 (d, 1, ArH), 7.22 (s, 1, ArH), 7.20 (d, 1, ArH),

6.68 (s, 1, ArH), 6.60 (s, 1, ArH), 4.31 (s, 2, ArCH₂N) , 4.09 (d, 1, ArCH₂CH, J = 11.2 Hz), 2.91 (m, 1, CHN), 2.72

(m, 2, ArCH₂) , 2.35 (s, 3, ArCH₃) , 2.16 (m, 1, CH₂CN, 1.85 ( , 1, CH₂CN) ; Anal. (C₁₈H₁₉N0₂) C, H, N. 2 . 11 .

2- (N-benzyl -N-3-ιιιethylbenzoyl) -6,7-dimβa-oxy-3,4-dibydro-2- naphthylamine

To a solution of 5.123 g (24.8 mmol) of 6,7-dimethoxy-β-- tetralone in 200 mL of toluene was added 2.929 g (1.025 equiv.) of benzylamine. The reaction was heated at reflux overnight under N₂ with continuous water removal. The reaction was cooled and the solvent was removed by rotary vacuum evaporation to yield the crude N-benzyl enamine as a brown oil.

Meanwhile, the 2-methylbenzoyl chloride acylating agent was prepared by suspending 4.750 g (42.2 mmol) of o-toluic acid in 100 mL benzene. To this solution was added 2.0 equiv. (7.37 mL) of oxalyl chloride, dropwise via a pressure-equalizing dropping funnel at 0 °C. DMF (2-3 drops) was added to the reaction mixture catalytically and the ice bath was removed. The progress of the reaction was monitored via infrared spectroscopy. The solvent was removed by rotary vacuum evaporation and the residual oil was pumped down under high vacuum overnight.

The crude N-benzyl enamine residue was dissolved in 100 mL of CH₂C1₂, and to this solution was added 2.765 g (1.1 equiv.) of triethylamine at 0 °C. 4-methylbenzoyl chloride (4.226 g, 27.3 mmol) was dissolved in 25 mL CH₂C1₂ and this solution was added dropwise to the cold, stirring N-benzyl enamine solution. The reaction was allowed to warm to room temperature and was left to stir under N₂ overnight. The reaction mixture was washed successively with 2 x 30 mL of 5% aqueous HCl, 2 x 30 mL of saturated sodium bicarbonate solution, saturated NaCl solution, and was dried over MgS0₄. After filtration, the filtrate was concentrated under vacuum. The resulting oil was purified via the chro atotron utilizing a 5% ether/dichloromethane eluent mobile phase to yield 3.950 g (38.5%) of the pure oil. CIMS (isobutane) ; M + 1 414; -NMR (CDCl₃) δ 7.34 (d, 2, ArH), 7.30 (m, 2, ArH) , 7.25 (d, 2, ArH) , 7.14 (m, 2, ArH) , 7.07 (m, 1,

ArH) , 6.47 (s, 1, ArH) , 6.37 (s, 1, ArH) , 6.04 (s, 1,

ARCH) , 4.96 (s, 2, ArCH₂N) , 3.78 (s, 3, OCH₃) , 3.77 (s,

3, OCH₃) , 2.39 (s, 3, ArCH₃) , 2.30 (t, 2, ArCH₂) , 1.94 (t, 2, CH₂) .

2.12.

Trans-4-methyl-6-benzyl-10,11-dimethoxy-5, 6, 6a,7,

8,12b-hexahydrobenzo[a]phenanthridine-5-one

A solution of 2.641 g (6.395 mmol) of the 6,7- dimethoxy enamide prepared above, in 450 mL of THF, was introduced to an Ace Glass 500 mL photochemical reactor. This solution was stirred while irradiating for 3 hours with a 450 watt Hanovia medium pressure, quartz, mercury- vapor lamp seated in a water cooled, quartz immersion well. The solution was concentrated in vacuo and crystallized from diethyl ether to provide 0.368 (20%) of the 10, 11 dimethoxy lactam, mp 175-176 °C. CIMS (isobutane); M + l 414; "H-NMR (CDC1₃) ; δ 7.88 (m, 3, ArH), 7.65 (d, 1, ArH), 7.40 (m, 2, ArH), 7.21 (m, 2, ArH), 6.87 (s, 1, ArH), 6.60 (s, 1, ArH), 5.34 (d, 1,

ArCH₂N) , 4.72 (d, 1, ArCH₂N) , 4.24 (d, 1, Ar₂CH, J = 10.9 Hz), 3.86 (s, 3, 0CH₃) , 3.85 (s, 3, OCH₃) , 3.68 (m, 1, CHN) , 2.73 (s, 3, ArCH₃) , 2.64 (m, 2, ArCH₂) ; 2.20 (m, 1, CH₂CN) , 1.72 (m, 1, CH₂CN) .

2.13.

Trans-4-methyl-6-benzyl-10,11-dimethoxy-5,6,6a,7, 8,12b-hexahydrobenzo[a]phenanthridinehydrochloride

A solution of 1.640 g (3.97 mmol) of the lactam prepared above, in 100 mL dry THF was cooled in an ice- salt bath and 4.0 equiv. (15.9 mL) of 1.0 molar BH₃ was added via syringe. The reaction was heated as reflux under nitrogen overnight. Methanol (10 mL) was added dropwise to the reaction mixture and reflux was continued for 1 hour. The solvent was removed by rotary vacuum evaporation. The residue was chased two times with methanol and twice with ethanol. The flask was placed under high vacuum (0.05 mm Hg) overnight. The residue was dissolved in ethanol and was carefully acidified with concentrated HCl. The violatiles were removed and the product was crystallized from ethanol to afford 1.288 g

(74.5%) of the hydrochloride salt, mp 232-235 °C. CIMS

(isobutane); M + l 400; ^XH-NMR (CDC1₂, free base) δ 7.38

(d, 2, ArH), 7.33 ( , 2, ArH), 7.27 (d, 1, ArH), 7.24 (m,

1, ArH), 7.16 (m, 1, ArH), 7.06 (d, 1, ArH), 6.85 (s, 1,

ArH), 6.71 (s, 1, ArH), 4.05 (d, 1, Ar₂CH, J = 10.8 Hz),

3.89 (d, 1, ArCH₂N) , 3.87 (s, 3, 0CH₃) , 3.82 ( , 1,

ArCH₂N) , 3.76 (s, 3, OCH₃) , 3.55 (d, 1, ArCH₂N) , 3.31 (d,

1, ArCH₂N) , 2.88 (m, 1, ArCH₂) , 2.81 (m, 1, CHN), 2.34

(m, 1, CH₂CN) , 2.20 (m, 1, ArCH₂) , 2.17 (s> 3, ArCH₃) ,

1.94 (m, 1, CH₂CN) .

2.14.

Trans-4-methyl-10, 11-dimethoxy-5, 6, 6a, 7, 8, 12b- hexahydrobenzo[a]phenanthridine hydrochloride

A solution of 0.401 g (0.92 mmol) of the 6-benzyl hydrochloride salt prepared above in 100 mL of 95% ethanol containing 100 mg of 10% Pd/C catalyst was shaken at room temperature under 50 psig of H₂ for 8 hours.

After removal of the catalyst by filtration through

Celite, the solution was concentrated to dryness under vacuum and the residue was recrystallized from acetonitrile to afford 0.287 g (90.2%) of the crystalline salt, mp 215-216 °C. CIMS (isobutane); M + l 310; ¹HNMR

(CDC1₃, free base) δ 9.75 (s, 1, NH) , 7.29 (d, 1, ArH),

7.28 (d, 1, ArH), 7.21 (m, 1, ArH), 6.86 (s, 1, ArH),

6.81 (s, 1, ArH), 4.35 (d, 1, ArCH₂N) , 4.26 (d, 1,

ArCH₂N) , 4.23 (d, 1, Ar₂CH, J = 11.17 Hz), 3.75 (s, 3,

0CH₂) , 3.65 (s, 3, 0CH₃) , 2.96 (m, 1, CHN), 2.83 (m, 2,

ArCH₂ ) , 2 . 30 ( s , 3 , ArCH₃ ) , 2 . 21 (m, 1 , CH₂CN) , 1 . 93 (m ,

1 , CH₂CN) . 2 . 15 .

Trans-4-methyl-10, ll-dihydroxy-5, 6, 6a, 7, 8, 12b- hexahydrobenzo[a]phenanthridine hydrochloride

0.485 g (1.40 mmol) of the 0,0-dimethyl hydrochloride salt prepared above was converted to its free base. The free base was dissolved in 35 mL of dichlbrometharie and the solution was cooled to -78 °C.

4.0 equiv. (5.52 mL) of a 1.0 molar solution of BBr₃ was added slowly via syringe. The reaction was stirred under N₂ overnight with concomitant warming to room temperature. 7.0 mL of methanol was added to the reaction mixture and the solvent was removed by rotary vacuum evaporation. The flask was placed under high vacuum (0.05 mm Hg) overnight. The residue was dissolved in water and was carefully neutralized to its free base initially with sodium bicarbonate and finally with ammonium hydroxide (1-2 drops) . The free base was isolated by suction filtration and was washed with cold water. The filtrate was extracted several times with dichloromethane and the organic extracts were dried, filtered and concentrated. The filter cake and the organic residue were combined, dissolved in ethanol and carefully acidified with concentrated HCl. After removal of the volatiles, the HCl salt was crystallized as a solvate from methanol in a yield of 0.364 g (81.6%), mp

(decomposes @ 195 °C) . CIMS (isobutane) ; M + 1 282; ^XH-

NMR (DMSO, HCl salt) δ 9.55 (s, 1, NH) , 8.85 (s, 1, OH),

8.80 (s, 1, OH), 7.28 (m, 2, ArH), 7.20 (d, 1, ArH), 6.65

(s, 1, ArH), 6.60 (s, 1, ArH), 4.32 (d, 1, ArCH₂N) , 4.26 (d, 1, ArCH₂N) , 4.13 (d, 1, Ar₂CH, J = 11.63 Hz), 2.92

(m, 1, CHN), 2.75 (m, 1, ArCH₂) , 2.68 (m, 1, ArCH₂) , 2.29 (s, 3, ArCH₃) , 2.17 (m, 1, C H₂CN) , 1.87 (m, 1, CH₂CN) .

Using the same procedures described above, and those described in U.S. Patent 5,047,536, the compounds set forth in Table 2 below are synthesized.

TABLE 2.

The affinity for the compounds of Entries 1, 2 and 4 for D-l and D-2 binding sites was assayed utilizing rat brain striatal homogenates having D-l and D-2 binding sites labeled with ³H-SCH 23390 and ³H-spiperone, respectively. The data obtained in that assay for dihydrexidine (DHX, Entry 1') and the compounds of Entries 1, 2 and 4 are reported in Table 3. TABLE 3.

D-l D-2 D-l:D-2

Entries Affinity Affinity Selectivity

1' (DHX) 8 nM 100 nM 13

1 14 nM 650 nM 46

2 7 nM 45 nM 6

4 290 nM 185 nM 0.6

Using the methods outlined in Example 1, dihydrexidine and its substituted analogs are resolved into their respective enantiomers, i.e., their (6aR, 12bS) - ( + ) - and (6aS, 12biR) -(-) -optical isomers. Accordingly, the following compounds, including their salts (especially their acetic and hydrochloride acid addition salts) , O-alkylated, and N-alkylated analogs, are provided by the methods of the present invention:

{6aR,12bS) - (+) -10, ll-dihydroxy-5 , 6 , 6a, 7, 8, 12b- hexahydro-benzo [a] phenanthridine;

(6aS, 12bR) - (-) -10, ll-dihydroxy-5 , 6, 6a, 7, 8, 12b- hexahydro-benzo [a] phenanthridine;

(6ai?,12bS) - ( + ) -2-methyl-10,ll-dihydroxy- 5, 6, 6a, 7, 8, 12b-hexa-hydrobenzo [a] phenanthridine ;

(6aS,12bJ?) - (-) -2-methyl-10, 11 - di hydroxy - 5, 6, 6a, 7, 8, 12b-hexa-hydrobenzo [a] phenanthridine ;

(6aR,12bS) - (+) -3- ethyl-10 , 11-dihydroxy- 5, 6, 6a, 7, 8, 12b-hexa-hydrobenzo [a] phenanthridine ;

(6aS, 12bi?) - (-) -3-methyl-10,ll-dihydroxy- 5, 6, 6a, 7, 8, 12b-hexa-hydrobenzo [a] phenanthridine;

(6af?,12bS) - ( + ) -4- me thy 1-10, 11 -di hydroxy - 5, 6, 6a, 7, 8, 12b-hexa-hydrobenzo [a] phenanthridine;

(6aS,12bR) - (-) -4-met yl-10, 11 - di hydroxy - 5,6, 6a, 7,8, 12b-hexa-hydrobenzo [a] phenanthridine;

(6ai?, 12b£) - ( + ) -2-phenyl-10, 11 -di hydro xy- 5,6, 6a, 7,8, 12b-hexa-hydrobenzo [a] phenanthridine; (6aS, 12bR) - (-) -2-phenyl-10, 11-dihydroxy- 5,6, 6a, 7,8, 12b-hexa-hydrobenzo [a] phenanthridine ;

(6aR,12bS) - ( + ) -N-methyl-2-methyl-10 , 11-dihydroxy- 5, 6, 6a, 7, 8, 12b-hexahydrobenzo [a] phenanthridine; (6aS, 12bR) - (-) -N-methyl-2-methyl-10 , 11 -dihydroxy -

5 , 6 , 6a , 7 , 8 , 12b-hexahydrobenzo [a] phenanthridine ;

(6aR, 12bS) - ( + ) -N-propyl-3-methyl-10, 11-dihydroxy- 5 , 6 , 6a , 7 , 8 , 12b -hexahydrobenzo [a] phenanthridine ;

(6aS, 12bJ?) - (-) -N-propyl-3-methyl-10, 11 -dihydroxy - 5, 6, 6a, 7, 8, 12b-hexahydrobenzo [a] phenanthridine ;

(6aR, 12bS) - (+) -2-ethyl-10 , ll-dihydroxy- 5 , 6 , 6a , 7 , 8 , 12b-hexa-hydrobenzo [a] phenanthridine ;

(6aS, 12bJ?) - (- ) -2-ethyl-10 , ll-dihydroxy- 5 , 6 , 6a , 7 , 8 , 12b-hexa-hydrobenzo [a] phenanthridine ; (6ai., 12b5) - ( + ) -3 -ethyl-10 , 11-dihydroxy-

5, 6, 6a, 7, 8, 12b-hexa-hydrobenzo [a] phenanthridine;

(6aS, 12bi?) - (- ) -3-ethyl-10 , ll-dihydroxy- 5, 6, 6a, 7, 8, 12b-hexa-hydrobenzo [a] phenanthridine;

(6aR, 12b5) - ( + ) -3 , 4 -dimethyl -10 -bromo- 11 -hydroxy - 5, 6, 6a, 7, 8, 12b- hexahydrobenzo [a] phenanthridine ;

(6aS, 12bJ?) - (-) - 3, 4 -dimethyl -10 -bromo- 11 - hydroxy - 5, 6 , 6a, 7, 8, 12b-hexahydrobenzo [a] phenanthridine ;

(6aJ?,12bS) - ( + ) -N-propyl-2 , 3 -dimethyl - 10 ,11- dihydroxy- 5 , 6 , 6a , 7 , 8 , 12b-hexahydrobenzo [a] phenanthridine ; (6aS,12bJ?) - (-) -N-propyl-2 , 3 -dimethyl - 10 ,11- dihydroxy- 5 , 6 , 6a , 7 , 8 , 12b-hexahydrobenzo [a] phenanthridine ;

(6aR, 12b5) - ( + ) -N-ethyl-3 , 4-dimethyl-10-bromo-ll- hydroxy-5, 6, 6a, 7, 8, 12b-hexahydrobenzo [a] phenanthridine;

(6aS, 12bi?) - (-) -N-ethyl-3,4-dimethyl-10-bromo-ll- hydroxy- 5, 6, 6a, 7, 8, 12b-hexahydrobenzo [a] phenanthridine;

(6aR, 12bS) - ( + ) -N-methyl-4-ethyl-10 , 11-dihydroxy- 5, 6, 6a, 7, 8, 12b-hexahydrobenzo [a] phenanthridine ;

(6a5, 12bi2) - (-) -N-methyl-4-ethyl-10 , 11-dihydroxy- 5 , 6 , 6a , 7 , 8 , 12b -hexahydrobenzo [a] phenanthridine ; (6aR,12bS) - (+) -N-butyl-3, 10, 11 - t r i hydroxy -

5, 6, 6a, 7, 8, 12b -hexahydrobenzo [a] phenanthridine; (6aS, 12bi?) - (-) -N-butyl-3, 10, 11 - t r i hydroxy - 5 , 6 , 6a , 7 , 8 , 12b-hexahydrobenzo [a] phenanthridine ;

(6aI2,12bS) - ( + ) -2 -methyl -3 , 10 , 11 - 1 r i hydroxy - 5 , 6 , 6a, 7, 8 , 12b-hexahydrobenzo [a] phenanthridine;

(6aS, 12bR) - (-) -2 -methyl -3 ,10, 11 - 1 rihydroxy- 5, 6, 6a, 7, 8, 12b -hexahydrobenzo [a] phenanthridine;

(6aR, 12b S) - ( + ) -3-fluoro-10, 11 - dihydroxy - 5,6, 6a, 7, 8,12b-hexa-hydrobenzo [a] phenanthridine;

(6aS , 12b R) - (-) -3-fluoro-10, 11 - dihydroxy - 5, 6, 6a, 7, 8, 12b-hexa-hydrobenzo [a] phenanthridine;

(6aR, 12bS) - (+) -10-bromo-2 , 11-dihydroxy- 5, 6,6a, 7, 8, 12b-hexa-hydrobenzo [a] phenanthridine;

(6aS, 12bK) - (-) -10-bromo-2 , 11-dihydroxy- 5, 6, 6a, 7, 8, l2b-hexa-hydrobenzo [a] phenanthridine;

(6aR, 12bS) - (+) -2-bromo-10 , 11-dihydroxy- 5, 6, 6a, 7, 8, 12b-hexa-hydrobenzo [a] phenanthridine ;

(6aS, 12bR) - (-) -2-bromo-10 , 11-dihydroxy- 5, 6, 6a, 7, 8, 12b-hexa-hydrobenzo [a] phenanthridine;

(6aR, 12bS) - ( + ) -3-bromo-10-methoxy-ll-hydroxy- 5 , 6 , 6a, 7 , 8 , 12b-hexahydrobenzo [a] phenanthridine ;

(6aS, 12bR) - ( - ) -3 -bromo-10-methoxy-ll-hydroxy- 5 , 6 , 6a, 7 , 8 , 12b-hexahydrobenzo [a] phenanthridine ;

(6aJ?, 12b5) - ( + ) -4 -bromo-10-methoxy-ll-hydroxy- 5, 6,6a, 7, 8, 12b-hexahydrobenzo [a] phenanthridine ;

(6aS, 12 bR) - (-) -4 -bromo- 10-methoxy-ll-hydroxy- 5 , 6 , 6a , 7 , 8 , 12b -hexahydrobenzo [a] phenanthridine ;

(6aJϊ, 12bS) - ( + ) - 2 -methyl -3 -bromo- 10 -met hoxy- 11- hydroxy-5 , 6 , 6a, 7 , 8 , 12b- hexahydrobenzo [a] phenanthridine ;

(6aS, 12bR) - (-) -2-methyl -3 -bromo-10-methoxy-ll- hydroxy-5, 6, 6a, 7, 8, 12b -hexahydrobenzo [a] phenanthridine;

(6ai?,12bS) - ( + ) -N-methyl-2-fluoro-10,ll-dihydroxy- 5, 6, 6a, 7, 8, 12b-hexahydrobenzo [a] phenanthridine;

(6aS, 12bR) - (-) -N-methyl-2-f luoro-10, 11-dihydroxy- 5 , 6 , 6a, 7, 8 , 12b-hexahydrobenzo [a] phenanthridine;

(6aR,12bS) - ( + ) -N-methyl-3-fluoro-10,ll-dihydroxy- 5, 6,6a, 7, 8, 12b-hexahydrobenzo [a] phenanthridine; (6aS,12bR) - (-) -N-methyl-3-fluoro-10, 11-dihydroxy- 5, 6, 6a, 7, 8,12b-hexahydrobenzo[a]phenanthridine;

(6aR,12bS) - (+) -N-methyl-4-fluoro-10, 11-dihydroxy- 5, 6, 6a, 7, 8, 12b-hexahydrobenzo [a]phenanthridine; (6aS, 12bR) - (-) -N-methyl-4-fluoro-10, 11-dihydroxy-

5, 6, 6a, 7, 8, 12b-hexahydrobenzo[a]phenanthridine;

(6al-.,12bS) - (+) -N-ethyl-10-fluoro-3,ll-dihydroxy- 5, 6, 6a, 7, 8, 12b-hexahydrobenzo [a]phenanthridine;

(6aS, 12bR) - (-) -N-ethyl-10-fluoro-3, 11-dihydroxy- 5, 6, 6a,7, 8, 12b-hexahydrobenzo [a]phenanthridine;

(6aR, 12bS) - (+) -N-ethyl-2-methyl-10-fluoro-3 , 11- dihydroxy-5, 6,6a,7,8,12b-hexahydrobenzo[a]phenanthridine;

(6a£, 12bJ?) - (-) -N-ethyl-2-methyl-10-fluoro-3, 11- dihydroxy-5, 6,6a,7, 8,12b-hexahydrobenzo[a]phenanthridine; (6a£,12bS) - (+) -N-ethyl-2-methoxy-4-methyl-10-fluoro-

11-hydroxy-5, 6 , 6a, 7, 8, 12b-hexahydrobenzo [a]phenanth¬ ridine;

(6aS,12bJ?) - (-) -N-ethyl-2-methoxy-4-methyl-10-fluoro- ll-hydroxy-5, 6, 6a, 7, 8, 12b-hexahydrobenzo [a] phenanth- ridine;

( 6aR , 12bS) - (+) -N-propyl-3-methoxy-10-chloro-ll- hydroxy-5, 6, 6a, 7, 8,12b-hexahydrobenzo[a]phenanthridine;

(6aS, 12bJ?) - (-) -N-propyl-3-methoxy-10-chloro-ll- hydroxy-5, 6, 6a, 7, 8,12b-hexahydrobenzo[a]phenanthridine; (6aR, 12bS) - (+) -N-propyl-4-methoxy-3-methyl-10- chloro-ll-hydroxy-5,6, 6a, 7, 8, 12b-hexahydrobenzo [a]phen¬ anthridine;

(6aS, 12bi?) - (-) -N-propyl-4-methoxy-3-methyl-10- chloro-11-hydroxy-5, 6, 6a, 7, 8, 12b-hexahydrobenzo [a]phen- anthridine;

( 6aR, 12bS) - (+) -N-propyl-2-ethoxy-10, 11-dihydroxy- 5, 6, 6a, 7, 8, 12b-hexahydrobenzo [a]phenanthridine;

(6a5,12bJ?) - (-) -N-propyl-2-ethoxy-10, 11-dihydroxy- 5, 6, 6a, 7, 8, 12b-hexahydrobenzo[a]phenanthridine; (6aJ?,12bS) - (+) -N-propyl-4 , 10 , 11-trihydroxy-

5, 6, 6a, 7, 8, 12b-hexahydrobenzo [a]phenanthridine; (6aS, 12bi?) - (-) -N-propyl-4 ,10, 11-trihydroxy- 5, 6, 6a, 7, 8, 12b-hexahydrobenzo [a]phenanthridine;

(6aR,12bS) - (+) -N-butyl-2-methyl-10, 11-dihydroxy- 5, 6,6a, 7, 8,12b-hexahydrobenzo[a]phenanthridine;

(6a≤M2bi?) - (-) -N-butyl-2-methyl-10,ll-dihydroxy- 5, 6, 6a, 7, 8,12b-hexahydrobenzo [a]phenanthridine;

(6ai?,12bS) - (+)-N-butyl-4-methyl-3,10,ll-trihydroxy- 5,6,6a,7,8,12b-hexahydrobenzo[a]phenanthridine;

(6aS,12bR) - (-) -N-butyl-4-methyl-3,10,11-trihydroxy- 5, 6, 6a, 7, 8, 12b-hexahydrobenzo [a]phenanthridine;

(6aJ?,12b5) - (+) -N-butyl-3-chloro-2,10,11-trihydroxy- 5, 6, 6a, 7, 8, 12b-hexahydrobenzo[a]phenanthridine;

(6aS, 12bJ?) - (-) -N-butyl-3-chloro-2,10,ll-trihydroxy- 5, 6, 6a, 7, 8, 12b-hexahydrobenzo[a]phenanthridine;

(6aR,12bS) - (+) -N-butyl-2-chloro-3,10, 11-trihydroxy- 5,6,6a,7, 8,12b-hexahydrobenzo[a]phenanthridine;

(6aS,12bl?) - (-) -N-butyl-2-chloro-3,10,11-trihydroxy- 5, 6,6a, 7, 8,12b-hexahydrobenzo [a]phenanthridine;

(6aR,12bS) - (+) -N-butyl-3-methyl-10-iodo-ll-hydroxy- 5, 6,6a, 7, 8,12b-hexahydrobenzo [a]phenanthridine;

( 6aS, 12bR) - { - ) -N-butyl-3-methyl-10-iodo-ll-hydroxy- 5, 6, 6a, 7,8, 12b-hexahydrobenzo[a]phenanthridine.

6.3.

Pharmacology 6.3.1. Methods

[³H] -SCH23390 was synthesized as described by Wyrick, S. et al. , in J^". Label . Comp. Radiopharm. 1986, 23 , 685-692. (±) -2 was synthesized as previously described. [³H] -Spiperone was purchased from A ersham Corp (Arlington Heights, IL) . Na¹²⁵I was supplied by New England Nuclear (Boston, MA) , and HEPES buffer was purchased from Research Organics, Inc. (Cleveland, OH) . SCH23390 was a gift from Schering Corp. (Bloomfield, NJ) or was purchased from Research Biochemicals Inc. (Natick, MA) . Domperidone and ketanserin were gifts of Janssen Pharmaceutica (New Brunswick, NJ) . Dopamine, cAMP, isobutyl methylxanthine (IBMX) , and chlorpromazine were obtained from Sigma Chemical Co (St. Louis, MO) . cAMP primary antibody was obtained from Dr. Gary Brooker

(George Washington University, Washington D.C.) , and secondary antibody (rabbit anti-goat IgG) covalently attached to magnetic beads was purchased from Advanced Magnetics, Inc. (Cambridge, MA) .

6.3.2.

D_x and D₃ Radioreceptor Assays

Radioligand binding followed the method of Schulz et al . (See, Schulz, D.W. et al. , in J. Neurochem. 1985, 45, 1601-1611) with minor modifications. For the rat studies, male Sprague-Dawley rats (Charles River,

Raleigh, NC) weighing 200-400 g were decapitated, and the brains quickly removed and placed into ice cold saline. After a brief chilling period, brains were sliced into 1.2 mm coronal slices with the aid of a dissecting block similar to that described by Heffner, T.G. et al. , in

Pharmacol . Biochem. Behav. 1980, 13 , 453-456. The striatum was dissected from two slices containing the majority of this region, and the tissue was either used immediately or stored at -70 °C until the day of the assay. After dissection, rat striata were homogenized by seven manual strokes in a Wheaton Teflon-glass homogenizer with ice cold 50 mM HEPES buffer with 4.0 mM MgCl₂, pH 7.4 (25 °C) . Tissue was centrifuged at 27,000 x g (Sorvall RC-5B/SS-34 rotor, DuPont, Wilmington DE) for 10 min, and the supernatant was discarded. The pellet was homogenized (five strokes) and resuspended in ice cold buffer and centrifuged again. The final pellet was suspended at a concentration of approximately 2.0 mg wet weight/mL. Assay tubes (1 mL final volume) were incubated at 37 °C for 15 minutes. Nonspecific binding of [³H] -SCH23390 (ca. 0.25 nM) was defined by adding unlabeled SCH23390 (1 μM) . Binding was terminated by filtering with 15 mL ice cold buffer on a Skatron or Brandel cell harvester (Skatron Inc., Sterling, VA; Brandel Inc., Gaithersburg, MD) using glass fiber filter mats (Skatron no. 7034; Brandel GF/B) .

Filters were allowed to dry, and 2-4 mL of Scintiverse E (Fischer Scientific Co., Fair Lawn, NJ) was added. After shaking for 30 min, radioactivity was determined on an LKB-1219 Betarack liquid scintillation counter. Tissue protein levels were estimated using the Folin reagent method of Lowry, O.H. et al. , in J^". Biol . Chem . 1951, 193 , 265-275, adapted to a Technicon Autoanalyzer I (Tarrytown, NY) .

For D₂-like receptors, the procedure was as described for D^like receptors with the following changes. [³H] -Spiperone was used as the radioligand, and non-specific binding of [³H] -spiperone was defined by adding unlabeled 1 μM chlorpromazine. Ketanserin (50 nM) was added to mask binding of [³H] -spiperone to serotonin receptors.

6.3.3.

Adenylate Cyclase Measurements: Striatum

The automated HPLC method of Schulz and Mailman (see, Schulz, D.W. and Mailman, R.B., in J^". Neurochem. 1984, 42, 16A -11A ) was used to measure adenylate cyclase activity by separating cAMP from other labeled nucleotides. Briefly, rat striatal tissue was removed and homogenized at 50 mL/g tissue in 5 mM HEPES buffer (pH 7.5) containing 2 mM EGTA. After homogenization with a Teflon-glass homogenizer, 50 mL/g of 100 mM HEPES-2 mM EGTA was added and mixed with one additional stroke. A 20 μL aliquot of this tissue homogenate was added to a prepared reaction mixture, yielding a final volume of 100 μL containing 0.5 mM ATP, 0.5 mM IBMX, [α³²P] -ATP (0.5 μCi) , 1 mM cAMP, 2 mM MgCl₂, 100 mM HEPES buffer, 2 μM GTP, 0 or 100 μM dopamine and/or drug, 10 mM phosphocreatine and 5U creatine phosphokinase. The reaction was initiated by transferring the samples from an ice bath to a water bath at 30 °C and terminated 16 minutes later by the addition of 100 μL of 3% sodium dodecyl sulfate. Proteins and much of the non-cyclic nucleotides were precipitated by the addition of 300 μL each of 4.5% ZnS0₄ and 10% Ba(0H)₂ to each incubation tube. The samples were centrifuged at 10,000 g for 8 minutes, and the supernatants removed and loaded onto an ISIS Autoinjector.

The HPLC separations were carried out using a Waters RCM 8 x 10 module equipped with a C18, 10 μm cartridge, using a mobile phase of 150 mM sodium acetate, 24% methanol, pH 5.0. A flow rate of 1.3 mL/min was used for separation. A UV detector set at 254 nm was used to measure the unlabeled cAMP, which was added to the sample tubes to serve as an internal standard and as a marker for the labeled cAMP. Sample recovery was based on UV measurement of total unlabeled cAMP peak areas. The radioactivity in each fraction was determined by an on¬ line HPLC radiation detector (Inus Systems, Tampa FL) .

6.3.4. Radioreceptor Assays in Transfeeted O₁ Receptors

The present studies were conducted with Ltk^" cells

(mouse fibroblasts) that expressed the human D^ receptor, L-hD^ (Liu, Y.F. et al. , in Mol . Endocrinol .

1992, 6, 1815-1824.) The cells were grown in DMEM-H medium containing 4,500 mg/L glucose, L-glutamine, 10% fetal bovine serum and 700 ng/mL G418. In these studies, D_x receptor levels were ca. 5,000 fmol/mg protein. All cells were maintained in a humidified incubator at 37 °C with 5% C0₂. Cells were grown in 75 cm² flasks until confluent. The cells were rinsed and lysed with 10 mL of ice cold hypoosmotic buffer (HOB) (5 mM HEPES, 2.5 mM MgCl₂, 1 mM EDTA; pH 7.4) for 10 minutes at 4 °C. Cells were then scraped from the flasks using a sterile cell scraper from Baxter (McGaw Park, IL) . Flasks received a final rinse with 5 mL of HOB. The final volume of the cell suspension recovered from each flask was ca. 14 mL. Scraped membranes from several flasks were then combined. The combined cell suspension was homogenized (10 strokes) , 14 mL at a time, using a 15 mL Wheaton Teflon- glass homogenizer. The cell homogenates were combined and spun at 43,000 x g (Sorvall RC-5B/SS-34, DuPont, Wilmington, DE) at 4 °C for 20 minutes. The supernatant was removed, and the pellet was resuspended (10 strokes) in 1 mL of ice cold HOB for each original flask of cells homogenized. This homogenate was then spun again at 43,000 x g at 4 °C for 20 minutes. The supernatant was removed and the final pellet was resuspended (10 strokes) in ice cold storage buffer (50 mM HEPES, 6 mM MgCl₂, 1 mM EDTA; pH 7.4) to yield a final concentration of ca. 2.0 mg of protein/mL. Aliquots of the final homogenate were stored in microcentrifuge tubes at -80 °C.

Prior to their use for radioligand binding or adenylate cyclase assays, protein levels for each membrane preparation were quantified using the BCA protein assay reagent (Pierce, Rockford, IL) adapted for use with a microplate reader (Molecular Devices; Menlo_. Park, CA) .

Frozen membranes were thawed and resuspended in assay buffer (50 mM HEPES with 6 mM MgCl₂ and 1 mM EDTA; pH 7.4) containing a fixed concentration of [³H]SCH23390 (0.2 nM) in a final assay volume of 500 L. Triplicate determinations were performed at data point. Assay tubes were incubated at 37 °C for 15 min. Tubes were filtered rapidly through Skatron glass fiber filter mats, and the filters rinsed with 5 mL of ice-cold assay buffer using a Skatron Micro Cell Harvester (Skatron Instruments Inc. , Sterling, VA) . Filters were allowed to dry, then punched into scintillation vials (Skatron Instruments Inc., Sterling, VA) . OptiPhase 'HiSafe' II scintillation cocktail (2 mL) was added to each vial. After shaking for 30 min, radioactivity in each sample was determined on an LKB Wallac 1219 Rackbeta liquid scintillation counter (Wallac Inc., Gaithersburg, MD) .

The foregoing examples of preferred embodiments are provided simply to illustrate the present invention.

Other embodiments of the present invention are apparent to one of ordinary skill in the art and are considered to fall within the scope and spirit of the present invention. Hence, the examples are not to be construed to limit the invention in any way, which invention is limited solely by the claims that follow.

Claims

WHAT IS CLAIMED IS:

1. A compound of the formula

and pharmaceutically acceptable salts thereof wherein the H_a and H_b are trans across ring fusion bond c, R is hydrogen or C_λ - C₄ alkyl R-_L is hydrogen or a phenol protecting group X is fluoro, chloro, bromo, iodo, or a group of the formula -OR₅ wherein R_s is hydrogen or a phenol protecting group, provided that when X is a group of the formula -0R₅, the groups R_z and R₅ can be taken together to form a group of the formula -CH₂-; and

R₂, R₃ and R₄ are independently selected from the group consisting of hydrogen, C₁-C₄ alkyl, phenyl, fluoro, chloro, bromo, iodo, or a group -ORi wherein R_x is as defined above, provided said compound is optically active.

2. The compound of claim 1 which is the (+) - isomer.

3. The compound of claim 1 which is the (-)- isomer.

4. The compound of claim 1 in which the groups R₂, R₃, and R₄ are all hydrogen. 5. The compound of claim 1 in which at least one of the groups R₂, R₃, and R₄ is methyl.

6. The compound of claim 1 wherein X is hydroxy and R is hydrogen or C^^ alkyl.

7. The compound of claim 1 wherein X is selected from the group consisting of fluoro, chloro, bromo, or iodo and R is hydrogen, methyl or n-propyl.

8. (6aR,12bS) - (+) -10, 11-dihydroxy-5, 6, 6a, 7, 8, 12b- hexa-hydrobenzo[a]phenanthridine, an O-alkylated or N- alkylated analog thereof, or its pharmaceutically acceptable acid addition salt.

9. (6aS,12bR) - (-)-10,ll-dihydroxy-5,6,6a,7,8,12b- hexa-hydrobenzo [a]phenanthridine, an O-alkylated or N- alkylated analog thereof, or its pharmaceutically acceptable acid addition salt.

10. (6ai?,12bS) - (+) -10, 11-dimethoxy-5, 6,6a,7, 8, 12b- hexa-hydrobenzo [a]phenanthridine, oritspharmaceutically acceptable acid addition salt.

11. (6aS,12bR) - (-) -10,ll-dimethoxy-5,6,6a,7, 8, 12b- hexa-hydrobenzo [a]phenanthridine, oritspharmaceutically acceptable acid addition salt.

12. (6aR,12bS) - (+) -6- (R-methoxyphenylacetyl) -10,11- dimethoxy-5,6,6a,7, 8,12b-hexahydrobenzo[a]phenanthridine, or its pharmaceutically acceptable acid addition salt.

13. (6aS, 12bR) - (-) -6- (R-methoxyphenylacetyl) -10,11- dimethoxy-5,6,6a,7, 8,12b-hexahydrobenzo[a]phenanthridine, or its pharmaceutically acceptable acid addition salt. 14. Use of a compound of claim 1 or 4 for the preparation of a medicament for treating a dopamine¬ related dysfunction of the central nervous system evidenced by an apparent neurological, psychological, physiological, or behavioral disorder.

15. A pharmaceutical composition for treating dopaminerelated dysfunction of the central nervous system by an apparent neurological, physiological, psychological, or behavioral disorder, said composition comprising a therapeutically effective amount of the compound according to claim 1 or 4 and a pharmaceutically acceptable carrier therefor.

16. A pharmaceutical composition comprising an effective amount of (6aR,12bS) - (+) -10,11-dihydroxy- 5, 6, 6a, 7, 8,12b-hexa-hydrobenzo[a]phenanthridine, an O- alkylated or N-alkylated analog thereof or its pharmaceutically acceptable acid addition salt and a pharmaceutically acceptable carrier.

17. A pharmaceutical composition comprising an effective amount of (6aR,12bS) - (+) -10, 11-dimethoxy- 5, 6, 6a,7, 8, 12b-hexa-hydrobenzo[a]phenanthridine, an N- alkylated analog thereof or its pharmaceutically acceptable acid addition salt, and a pharmaceutically acceptable carrier.

18. A method of resolving racemic 10, 11-dihydroxy- 5 , 6 , 6a , 7 , 8 , 12b-hexahydrobenzo [a] phenanthridine comprising:

(a)providing a 10, 11-diprotected analog of 10,11-dihydroxy-5,6,6a,7,8,12b-hexahydrobenzo[a]phenanth¬ ridine;

(b) allowing said 10, 11-diprotected analog to react with a chiral auxiliary ligand that is a homochiral alpha-alkoxyphenylacetyl halide to provide a pair of diastereomers;

(c) separating said pair of diastereomers into its component stereoisomers to provide a resolution of said racemic 10,11-dihydroxy-5, 6, 6a, 7, 8, 12b-hexahydro- benzo [a]phenanthridine.

19. The method of claim 18 which further comprises removing said chiral auxiliary ligand from one of said component stereoisomers.

20. The method of claim 19 which further comprises regenerating said 10, 11-dihydroxy-5, 6, 6a,7, 8,12b- hexahydrobenzo [a]phenanthridine from its 10,11- diprotected analog, said 10, 11-dihydroxy-5, 6, 6a, 7, 8, 12b- hexahydrobenzo [a]phenanthridine being optically active.

21. Crystalline (6aR, 12bS) - (+) -10, 11-dihydroxy-

5,6, 6a, 7, 8, 12b-hexahydrobenzo[a]phenanthridine as its pharmaceutically acceptable acid addition salt.

22. The compound of claim 21 which is the hydrochloride.

23. Use of a compound of claim 8 for the preparation of a medicament for alleviating the effects of Parkinson's disease, CNS movement-related disorder, or cardiovascular disorder.

2 . Use of a compound of claim 8 for the preparation of a medicament for enhancing endocrine function.