Über Koproester-verdohämin und seine Umwandlung in Kopro-bilirubin

Abstract

Coproporphyrin I ester was prepared by melting at 165[degree], 80 g. of partially dehydrated citric acid and slowly adding 30 g. of 5-bromo[long dash]4,3[image],5[image]-trimethylpyrromethene-3,4[image]-dipropionic acid HBr. The mixture was heated to 210[degree], and poured into 1 1. of 2 N NH3. The NH3 soln. was poured into 2 vols. of 2 N HC1, the mixture filtered, and coproporphyrin dihydrochloride crystallized from the red soln. The dihydrochloride was esterified by heating with 200 cc. of 10% methyl alcoholic HC1. Coprochlorohemin I ester was prepared by dissolving 1 g. of reduced Fe in 500 cc. boiling acetic acid and adding 12 cc. of saturated NaCl soln. followed by 6 g. of the copro I ester dissolved in 60-80 cc. CHC13. The pyridineco-prohemochromogen I ester was formed by treating 5 g. of the coprochlorohemin I ester dissolved in 200 cc. of pyridine with 10 cc. of hydrazine hydrate soln. (1:10). Hydroxyco-prochlorohemin I ester was formed by dissolving 922.3 mg. of the pyridinecoprohemochromogen I ester in 300 cc. of pyridine at 60[degree], and slowly adding 10 cc. of 1% H2O2 dissolved in pyridine. The mixture was evaporated to dryness, and the product purified by dissolving in 5 cc. CHCl3 and adding 50 cc. of 3% methyl alcoholic HC1. Coproverdo-hemin ester, probably C40H43O9N4FeCl2, a greenish black, crystalline powder, m. 192[degree]-194[degree], was prepared by shaking 0.6 g. of the hydroxycoprochlorohemin I ester in 150 cc. of pyridine in 0 for 5 hrs. at 55[degree]-60[degree]. The pyridine was then evaporated and the residue treated with hot MeOH-HCl. When 200 mg. of the coproverdohemin ester were dissolved in 80 cc. MeOH and treated with 2 g. KOH in 20 cc. MeOH, followed by HC1, coproglaucobilin ester I a, (C39H46O10N4), m. 208[degree], was formed. Coprobilirubintetramethyl ester I a dihydrochloride, (C39H48OioN4.2HCl), m. 197[degree]-200[degree] was obtained by reduction of the coproglaucobilin ester with Zn dust in acetic acid soln.