Papaverin

CgHjoO,. A compound of largely historical interest for its role in establishing the structure of many natural products. Methylation of vanillin gives veratraldehyde which may be oxidized to veratric acid. Veratric acid was identified as a degradation product of the alkaloid papaverine. 

Supplement XXI, 2nd 1935 3032-3457 Hydroxy-pyridine, 43. Indoxyl, 69. Hydroxyquinoline, 77. Papaverine, 220. 

Review Problem 4 This compound (TM 78) is an important intermediate in the synthesis of alkaloids Treatment with POCI3 gives the poppy alkaloid papaverine. How would you make TM 78 from simple starting materials ... 

Opium is the dried, powdered sap of the unripe seed pod of Papaver somniferum, a poppy plant indigenous to Asia minor. Theophrastus described its medical properties in the third century BC, but the Sumerians, ca BC 4000, probably perceived its utility. Arab physicians knew of the dmg, and Arab traders carried it to the Orient where it was used as a treatment for dysentery. Paracelsus is credited with repopularizing the dmg in western Europe in the early sixteenth century by formulating opium into "laudanum", which is still in use. More than 20 different alkaloids (qv) of two different classes comprise 25% of the weight of dry opium. The benzylisoquinolines, characterized by papaverine [58-74-2] (1.0%), a smooth muscle relaxant, and noscapine [128-62-1] (6.0%), an antitussive agent, do not have any analgesic effects. The phenanthrenes, the second group, are the more common and include 10% morphine (1, = R = H), 0.5% codeine [76-57-3], C gH2 N03, (1, R = H, R = CH3), and 0.2 thebaine [115-37-7], C 2H2 N03, (2). 

Papaverine, used to treat heart diseases as a vasodilator, is a dmg that was originally made from vanillin but has since been made from veratrole and (9f2v (9-l,2-dimethoxybenzene. Vanillin is also used as a pharmaceutical excipient. 

Verapamil. Verapamil hydrochloride (see Table 1) is a synthetic papaverine [58-74-2] C2qH2 N04, derivative that was originally studied as a smooth muscle relaxant. It was later found to have properties of a new class of dmgs that inhibited transmembrane calcium movements. It is a (+),(—) racemic mixture. The (+)-isomer has local anesthetic properties and may exert effects on the fast sodium channel and slow phase 0 depolarization of the action potential. The (—)-isomer affects the slow calcium channel. Verapamil is an effective antiarrhythmic agent for supraventricular AV nodal reentrant arrhythmias (V1-2) and for controlling the ventricular response to atrial fibrillation (1,2,71—73). 

SPEKTROPHOTOMETRIC DETERMINATION OF INDIUM BIS(2,3,4-TRIHYDROXYPHENILAZO)BENZIDINE IN PRESENCE PAPAVERINE, DIBAZOL, UROTROPIN... 

Reaktions of complexes formation of In(III) with bis-(2,3,4-trioxy-phenylazo)benzidine (R) in presence of papaverine (Pap), dibazole (Dib), urotropine (Ur) has been studied by the spektrophotometric method. It has been established that the optimal conditions of complex formation for complexes of In(III) R-Pap, In(III) R-Dib and In(III) R-Ur are pH=2. 

Papaverine (2) POCI3 (423 mg 3 mmol) was added dropwise to relluxing 1 (423 mg 3 mmoO in MeCN After 1 h the mature was poured mto ice water washed (EtaO) basified (2N NH4OH), extracted with EtOAc and chromatographed to give 371 mg ol 2 (87%)... 

At about the same time, Vogtle and Frensch reported the synthesis of a similar bis-crown based on the papaverine nucleus. This synthesis also was executed in the Williamson fashion using doubly-demethylated papaverine and tetraethylene glycol dichloride. The base, if used, was not specified but it was noted that the high dilution technique was not used. It was presumed that the major product was 10, shown below, but there was also evidence of other components, presumably 11 and 12. 

Note The reagent can be employed on silica gel and cellulose layers. When derivatization is carried out from the vapor phase the detection limit for morphine is 10 ng and that for papaverine 1 ng per chromatogram zone [5]. In some cases it has been recommended that ammonium sulfate be added to the layer with subsequent heating to 150 —180 °C [1] after derivatization. It is also possible to spray afterwards with an aqueous solution of potassium iodide (1 %) and starch (1%) [2]. 

According to Gvishiani, in experiments on cats and mice salsoline resembles papaverine in its effects on blood circulation and hydrastinine in its action on smooth muscle. Its use in Russia for the treatment of hypertension has been reported. ... 

Experiments in the selection of poppies for morphine production have also been made in Germany by Kiissner. The yields from capsules of two selections, over two years, were morphine 0-257 to 0-544 per cent, and codeine 0-011 to 0-029 per cent. From seven commercial varieties grown in plots of 50 square metres, the yields in grammes per square metre were seeds 141 to 200, capsules 65 to 116, morphine 0-123 to 0-471 and non-phenolic bases (codeine, thebaine, papaverine, narcotine, etc.) 0-043 to 0-131. 

Estimation of Other Alkaloids in Opium. Of the other alkaloids the most important is codeine, and processes for its estimation in opium have been described by Cespari, Andrews,and Annett and co-workers methods for its assay in admixture with other drugs in tablets and other products are also available. The estimation of papaverine has been described by Issekutz,i and of narcotine by Snesarov. As to methods for the separation and estimation of two or more of these subsidiary alkaloids, codeine and narcotine have been dealt with by van der Widen,narcotine and papaverine by Annett and Bose, ( and the bromination of codeine and narceine has been studied by Vaisberg et al. with a view to estimation by this means. 

The first scheme for the separation of the six chief alkaloids of opium, VIZ., morphine, codeine, thebaine, papaverine, narcotine and narceine, is probably that of Plugge. Much later Kljatschkina investigated for each of these six bases the properties by means of which isolation and estimation could probably be effected and, on the basis of the results, devised a plan for such analyses. More recently Anneler has published a detailed account of a scheme with the same objective. l Attention had already been given to complex, systematic analyses of this kind, in connection with examination of the mixtures of opium alkaloids, which have long been in use in medicine in these at first only morphine and other alkaloids were determined, but in the more recent schemes provision is made for the estimation of each alkaloid. ... 

Benzylisoquinoline Derivatives. Papaverine, C20H21O4N Xanthaline, C20H19O5N dZ-Laudanine, C20H25O4N Laudanidine, C20H25O4N Codamine, C20H25O4N Laudanosine, C21H27O4N... 

Xanthaline has been shown to be papaveraldine (p. 182). The alkaloid tritopine is identical with laudanidine, now known to be Z-laudanine. Gnoscopine is dZ-narcotine. Merck s pseudopapaverine is papaverine. 

The processes used in the manufacture of morphine are believed to be still based on that described by the Scottish chemist Gregory,in 1833, with improvements devised by Anderson. A description has been published by Schwyzer, who also deals with the manufactme of codeine, narcotine, cotarnine, and the commercially important morphine derivatives, diamorphine (diacetylmorphine), and ethylmorphine (morphine ethyl ether). More recently Barbier has given an account of processes, based on long experience in the preparation of alkaloids from opium. Kanewskaja has described a process for morphine, narcotine, codeine, thebaine and papaverine, and the same bases are dealt with by Chemnitius, with the addition of narceine, by Busse and Busse, and by Dott. It is of interest to note that a number of processes for the extraction and separation of opium alkaloids have been protected by patent in Soviet Russia. ... 

Papaverine, C20H21O4N. This alkaloid, first obtained by Merck, occurs in the mixture precipitated by ammonia from the mother liquors of opium extract from which morphine and codeine have been separated in Gregory s process, and methods for its isolation from this mixture have been published by Hesse and others. The alkaloid may be purified by conversion into the acid oxalate, B. H2C2O4, m.p. 196° or 201-5-202°, which is nearly insoluble in alcohol. 

Papaverine crystallises in rhombic prisms or needles, m.p. 147°, [a]n 0°, is insoluble in water, soluble in hot alcohol or chloroform, and slightly so in cold alcohol or ether. It is a weak base for which, according to Wales, there is no satisfactory indicator, though bromophenol-blue has its colour change at the right point for this alkaloid. The hydrochloride, B. HCl, forms monoclinic plates, m.p. 225-6°, sparingly soluble in water (1 in 37 at 18°). The picrate forms quadratic plates, m.p. 186°. ... 

In this, the first serious and successful work on the structure of a complex alkaloid, there was naturally at first some confusion between Moquinoline and the better-known quinoline. The 6 7-dimethoxy-woquinolinecarboxylic acid was thought to be a dimethoxycinchoninic acid. It known, however, that quinoline benzylchloride on oxidation furnished formylbenzylanthranilic acid, CjH4(COOH)—N(C,H,)—CHO, whereas various papaverine alkyl halides gave what were presumed to be... 

The position in which the veratryl residue is attached to this isoquinoline nueleus in papaveraldine and papaverine is determined by the formation of pyridine-2 3 4-tricarboxylic acid in the oxidation of papaverine by hot permanganate. On the basis of these results, Goldschmiedt assigned the following formula to papaveraldine —... 

Papaverinic acid, CieHjjO N. HjO, crystallises in small tablets, m.p. 233°. It is dibasic, readily forms an anhydride, furnishes an oxime and a phenylhydrazone, contains two methoxyl groups, and on oxidation yields veratric and pyridine-2 3 4-tricarboxylic acids, and hence is represented by the following formula —... 

CeH3(OCH3)a. CHOH. CHa. NH. CO. CHg. CeH3(OCH3)2, which when boiled with phosphoric oxide in xylene solution lost 2 mols. of water and formed papaverine (IV). ... 

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