Info Rjo
Consonant with the present interest in chiral synthesis, two additional contributions can be cited. Sih et al . utilized a combined microbiological and organic chemical sequence in which key chirality establishing steps include the conversion of Y _ to chiral, but unstable, 18 by enzymic reduction using the fungus Diplodascus uninucleatus. Lower side-chain synthon 20 was prepared by reduction of achiral 19_ with Pencillium decumbens. Stork and Takahashi5 took D-glyceraldehyde synthon 21 from...
I Vbt
these drugs is directly related to the ability of this group to form an irreversible covalent bond with the genetic material of cells, that is, with DMA. Since this alkylated material can then no longer perform its function, replication of the cell is disrupted. The slight selectivity shown for malignant cells by the clinically used alkylating agents depends largely on the fact that these divide more rapidly than those of normal tissue. There have been many attempts to achieve better tissue...
Ciprocinonide Intermediates
then displaced by chlorine by means of triphenylphosphine and carbon tetrachloride 53 . Sequential reductive elimination 54 followed by saponification gives the allylic alcohol 55. Reaction with the Simmons-Smith reagent affords the corresponding cyclopropane, J56, the stereochemistry being determined by the adjacent hydroxyl group. Addition of the dianion from propargyl alcohol to the carbonyl group at position 17 adds the required carbon atoms for the future lactone 57 . The side chain is...
Info Fay
Piridlci11in 3, 207 Piridocaine 1, 13 Pirindol _1 gt 45 Piritramide 308 Pi rmentol 3, 48 Piroctone 3_, 149 Pirogl i ride 57 Pirol ate 3, 245 Piromidic acid 2, 470 Pirprofen 2, 69 Pivampicillin 414 Pizoctyline 2, 420 Pol dine methylsulfate 2, 74 Polythiazide I, 360 Practolol 2, 106, 108 Pranolium chloride 2, 212 Pramoxine 18 Prazepam 2, 405 Prazocin 2, 382 3, 194 Prednimustine 93 Prednisolone 192 2, 178 Prednisolone acetate 192 Prednisone 192 Prednival 2, 179 Prednylene 197 Prenalterol 3, 30...
Piperidines
Still further simplification of the structural requirements for central analgesic activity came from the serendipitous observation that the simple phenyl pi peri dine, meperidine 34 , shows biological activity almost indistinguishable from that of morphine. Further elaboration of that molecule led to one of the most potent opioid analgesics, fentanyl In-depth investigation of the structure activity relationships in the fentanyl meperidine series in the Janssen laboratories revealed that...
CI Rgf
Piperidinobenzimidazole also serves as starting material for the antipsychotic agent halopemide 69 . In the absence of a specific reference, one may speculate that the first step involves alkylation with bromochloro-ethane to give halide 67_. The chlorine may then be converted to the primary amine 68_ by any of several methods such as reaction with phthalimide anion followed by hydrazinolysis. Acylation with jj-fluorobenzoyl chloride then gives the desired product. A still different scheme is...
Info Hsn
4.MISCELLANEOUS HETEROCYCLES A cinnamoylpiperazine is described as an antianginal agent. The key intermediate 73_ can, in principle, be obtained by alkylatlon of the monobenzyl derivative of piperazine 71 with ethyl bromoacetate 72 . Removal of the protecting group then affords the substituted piperazine 73 . Acylation of this with 3,4,5-trimethoxycinamoyl chloride gives cinepazet 74 . C6H5CII2N Nil - RN _ NCI 2CO 2C2II5 - CH3 -CH CHCN 71 72 R C6H5CH2 74 Though dental afflictions constitute a...
Info Ubo
with acetic anhydride to give the 2-methyl-1,3,4-oxadiazol-5-yl analogue. 10 gt 11 The mechanism of this rearrangement is believed to involve N-acetylation 35 with subsequent ring opening to the diazoalkane 36 which loses nitrogen to give carbene 3 _, which cyclizes to the oxadiazole 38 .12 A phenylacetonitrile derivative, closantel 41 , is an anthelmintic agent useful against sheep liver flukes. Its patented synthesis involves a Schotten-Baumann amidation between acid chloride and complex...
Q
Excessive activity of the enzyme aldose reductase sometimes accompanies diabetes. The net result is often accumulation of reduced sugars such as galactose in the lens of the eye and ensuing cataract formation. A1restatin 43 , an aldose reductase inhibitor, is one of the first agents found that holds promise of preventing diabetes-induced cataracts. The compound, actually used as its sodium salt, is prepared in straightforward manner by imide formation between 1,8-naphthalic anhydride 41 and...
Info Fdg
The widely used tricyclic antidepressant drugs such as imipramine and amitriptyptiline have in common a series of side effects that limit their safety. There has thus occasioned a wide search for agents that differ in structure and act by some other mechanism. Nisoxetine and fluoxetine are two nontricyclic compounds which have shown promising early results as antidepressants. Mannich reaction on acetophenone leads to the corresponding aminoketone 78 . Reduction of the carbonyl group 79 followed...
II Fpj
Organic nitrite esters such as nitroglycerin have constituted standard treatment for anginal attacks for the better part of the century. These agents, which are thought to owe their efficacy to reducing the oxygen demand of the heart, as a class suffer from poor absorption and very short duration of action. Nicordani1 18 represents an attempt to overcome these shortcomings by combining a nitrite with nicotinate, the latter moiety itself having some vasodilating action. The drug is obtained in...
REFERENCES Ibl
1. M. A. Los, U.S. Patent 4,255,581 Chem. Abstr., 95, 62002x 1981 . 2. G. Y. Lesher and C. J. Opalka, Jr., U.S. Patent 4,107,315 Chem. Abstr. 90, 103844r 1979 . 3. H. Nagano, T. Mori, S. Takaku, I. Matsunaga, T. Kujirai, T. Ogasawara, S. Sugano, and M. Shindo, German Offen, 4,714,713 Chem. Abstr., 88, 22652h 1978 . 4. G. Lohaus and W. Dittmar, German Patent 1,795,831 Chem. Abstr., 89, 197347k 1978 . 5. E. Wehinger, H. Meyer, F. Bossert, W. Vater, R. Towart, K. Stoepel, and S. Kazada, German...
Info Ieq
Mecl oris one butyrate 3 , 95 Medazepam 368 Medibazine 2, 30 Mediquox 2, 390 Medrogestone 182 Medroxalol 3, 25 Medroxyprogesterone 1, 180, 186 2, 165 Medrylamine 41 Medrysone 2, 200 Mefenamic acid 110 2, 280 Mefenorex 2, 47 Mefexamide 2, 103 Mefruside I, 134 Megesterol acetate 180 Melengesterol acetate 1, 182, 187 Melitracen 2, 220 Melphalan 2, 120 Memotine 2, 378 Menoctone 2, 217 Meobentine 3 , 45 Meparfynol 38 Meperidine 300 2, 328 3, 116 Mephenhydramine 44 Mephenesin 118 Mephenesin carbamate...
REFERENCES Qdk
1. J. L. H. Van Gelder, A. H. M. Raeymaekers, L. F. C. Roevens and W. J. Van Laerhoven, U.S. Patent 3,925,383 Chem. Abstr., 84, 180264e 1976 . 2. L. D. Spicer and J. J. Hand, French Demande 2,199,979 Chem. Abstr., 82, 16835e 1975 . 3. J. Gubin and G. Rosseels, German Offen 2,707,048 Chem. Abstr., 88, 6719e 1978 . 4. J. P. Maffrand and F. Elloy, Eur. J. Med. Chem., 9, 483 1974 . 5. H. J. Shaeffer, German Offen., 2,539,963 1976 . 6. J. Diamond, German Offen., 2,713,389 Chem. Abstr., 88, 22984t...
Ocii 1
A number of muscle relaxants are useful anthelmintic agents. They cause the parasites to relax their attachment to i.he gut wall so that they can be eliminated. One such agent is carbantel 9 . Its synthesis follows the classic pattern of reaction of 4-chlorophenylisocyanate with jvamylamidine.5 To prepare another such analogue, J -methylation of 'licarbomethoxythiourea gives K , which itself reacts with com-PI ex aniline analogue 21 to 9ive the veterinary anthelmintic lt iyent fel santel 12 .6...
Niicm 1
Topical fungal infections usually involve the lipid-1 ike dermal and subdermal tissues. Drugs with increased lipophilicity would thus be expected to show enhanced antifungal activity by reason of preferential distribution to the lipid-rich site of action. A modification of the antifungal agent tolnaftate 29 , which increases its lipophilicity, affords toi ci elate 28 . One approach to construction of the required bridged tetrahydronaphthol 25 involves Diels-Alder condensation of a benzyne. Thus...
Info Xpc
hydrogenolysis to put the requisite alkyl side chain in pi act in 41. Ether cleavage HBr HOAc is followed by condensation with piperidone 42 to give tricyclic 43. Reaction with methylmagnesium bromide and hydrogenolysis of the benzylamine linkagi followed by alkylation gives 38.12 4. BENZODIOXANE DERIVATIVES In the 3-adrenergic blocking drug pyrroxan 48 , the catechol moiety is masked in a doxane ring. The synthesis begins by alkylation of phenyl acetonitrile by 2-chloroethanol to produce...
Info Syr
vice farther results in the pseudocatechol, procaterol 6 . on Friedel-Crafts alkylation of 8-hydroxycarbostyrils, such as leads to substitution at the C-5 position, namely, In this case an a-haloacyl reagent is employed. Displacement with iso-propylamine and careful sodium borohydride reduction care is needed to avoid reduction of the carbostyril double bond leads to procaterol 6 . Procaterol is an adren-ergic agonist selective for 32-receptors. Thus it dilates bronchioles without significant...
REFERENCES Asp
1. P. D. Hammen and G. M. Milne, German Offen., 2,360,096 Chem. Abstr., 81, 105093 1974 . 2. D. R. Buckle, N. J. Morgan, J. W. Ross, H. Smith, and B. A. Spicer, Med. Chem., 16, 1334 1973 . 3. S. J. DeSolm, D. W. Woltersdorf, E. J. Cragoe, L. S. Waton and G. M. Fanelli, J. Med. Chem. j .,437 1978 . 4. S. Reinhard, J. Org. Chem., 40, 1216 1975 . 5. H. Tanida, R. Muneyuki and T. Tsuji, Bull. Chem. Soc. Jap., 37, 40 1964 . 6. P. Melloni, M. Rafael a, V. Vecchietti, W. Logemann, S. Castellino, G....