Dipyridamol

Initially, it was beheved that the abiUty of xanthines phosphodiesterase (PDF) led to bronchodilation (Fig. 2). One significant flaw in this proposal is that the concentration of theophylline needed to significantly inhibit PDE in vitro is higher than the therapeutically useful semm values (72). It is possible that concentration of theophylline in airways smooth muscle occurs, but there is no support for this idea from tissue distribution studies. Furthermore, other potent PDE inhibitors such as dipyridamole [58-32-2] are not bronchodilators (73). EinaHy, although clinical studies have shown that neither po nor continuous iv theophylline has a direct effect on circulating cycHc AMP levels (74,75), one study has shown that iv theophylline significant potentiates the increase in cycHc AMP levels induced by isoproterenol (74). 

Piperidines. A significant use of piperidine (18) has been ia the manufacture of vulcanization accelerators, eg, thiuram disulfide [120-54-7] (115) (see Rubber chemicals). Mepiquat dichloride [24307-26-4] the dimethyl quaternary salt of (18), is used as a plant growth regulator for cotton (qv). Piperidine is used to make vasodilators such as dipyridamole [58-32-2] (116) and minoxidil [38304-91-5] (117), and diuretics such as etozoline [73-09-6] (118). 

Administration of dipyridamole-AMP to mice 5—25 min after 1 Gy (100 rad) of TBI y-kradiation is also protective, as indicated by plasma thymidine levels and the amount of saline soluble polynucleotides in the thymus (112). Adding dipyridamole-AMP to in vitro kradiated suspensions of thymocytes enhances the rejoining of DNA strand breaks (112). These post-kradiation effects ate presumably mediated by the activation of extraceUulat adenosine receptors. 

It was discovered that 3-iiitro-2-piperidiiio-, 3-iiitro-7-piperidiiio-, and 7-A -diethaiiolamiiio-3-iiitro-l, 8-iiaphthyridiii-2(lH)-oiies and 2-diethanol-amino-7-piperidino-3-nitro-l,8-naphthyridine showed remarkable aetivity to inhibit human platelet aggregation in vitro indueed by araehidonie aeid, eollagen, and ADR Tliis aetivity was eomparable to papaverine, dipyridamole, and ibuprofen (94EJMC735). 

Urea maybe reacted with acetoacetic ester and that product nitrated to give 5-nitro-orotec acid That is hydrogenated, then reacted with urea and potassium cyanate to give tetrahydroxypy-imidopyrimidine. The tetrahydroxy compound Is converted to the tetrachloro compound POCI3. Reaction with diethanolamine and then with piperidine gives dipyridamole. 

Acetoacetic acid methyl ester Nifedipine Acetoacetic ester Dipyridamole Acetoin... 

Dicyclohexylguanidium adenosine 5 -phosphoramidate Adenosine triphosphate Diethanolamine Dipyridamole Ditazol... 

Di-n-propylacetyl chloride Anistropine methyl bromide Di-n-propylamine Probenecid Dipyridamole Mopidamol... 

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