Corlopam,Pharmaforce, Inc.
dopamine receptor agonists
Dopamine D1-receptor agonist. Antihypertensive.
The dopamine receptors play important role in cognition, memory, learning, and motor control (1). These receptors have been implicated as a therapeutic target for many psychiatric and neurological disorders. Fenoldopam is a selective dopamine 1 receptor agonist with diuretic and properties (2,3).
ChEBI: Fenoldopam is a benzazepine. It has a role as a dopaminergic antagonist, a vasodilator agent, an alpha-adrenergic agonist, a dopamine agonist and an antihypertensive agent.
2-Chloro-3,4-dimethoxyphenethylamine (1.0 g) was reacted with 0.70 g of pmethoxystyrene
oxide to give the hydroxyphenethylamine; m.p. 118.5-121°C.
This compound (2.16 g) was stirred at room temperature in 15 ml of
trifluoroacetic acid with 4 drops of conc. sulfuric acid. After purification over a
silica gel column with chloroform, 10% methanol/chloroform as eluates, was
obtained 6-chloro-7,8-dimethoxy-1-p-methoxyphenyl-2,3,4,5-tetrahydro-1H-
3-benzazepine (0.78 g), m.p. 143-145°C.
The trimethoxy product (0.87 g, 2.50 mmoles) in 25 ml of dry methylene
chloride was cooled in an ice-methanol bath and 12.5 ml (25.0 mmoles) of
boron tribromide in methylene chloride was added dropwise. After stirring for
4 hours, the mixture was cooled in an ice bath while methanol was carefully
added to give 0.37 g of 6-chloro-7,8-dihydroxy-1-p-hydroxyphenyl-2,3,4,5-
tetrahydro-1H-3-benzazepine hydrobromide, m.p. 215°C.
The base was regenerated from the hydrobromide salt using sodium carbonate solution in 85% yield. Treating the base with various acids gave the
following salts: dl-tartrate, fumarate, hydrochloride, sulfate, and the most
water soluble one, the methanesulfonate, m.p. 272°C.
Selective D 1 -like dopamine receptor partial agonist (EC 50 = 57 nM). Vasodilator in vivo and does not readily cross the blood-brain barrier. Also α 2 -adrenoceptor antagonist in vitro (K i = 15-25 nM).
