Papaverine Crown Ethers

Abstract

is not possible [']. We have succeeded in preparing this complex, however, by reaction of ( 3 a ) with boron trichloride.Compound ( 4 ) precipitates as bright red, needle-like crystals, (decomp. pt. 105 "C), has solubility properties comparable to those of (3 a ) and ( 3 b), but, unlike the latter two compounds, is extremely sensitive toward air and moisture. Its structure was also confirmed by spectroscopic and analytical data. Molecular weight determinations and the mass spectrum are consistent with the monomeric structure of the complex. IR spectrum: v C 0 (in CH2CI2): 2075 (s,Al), 1985 (m,Al), 1960 (s,E) cm-'; vGe--Cl (in Nujol): 360 (w), 320 (w) cm-'. The germylene complexes ( 3 a ) , (3b), and ( 4 ) can be readily converted into the corresponding ylide complexes by addition of bases (ether, tertiary amines, or tertiary phosphanes). ExperimentalPreparation of (3a) and (3b): 20 mmol of (2) or ( 3 ) [4.48 g ( 2 ) ; 2.40g (3)] is added dropwise to a solution of (1) (IOmmol, 2.04g) in benzene (30ml) and the mixture is stirred for 30min at 50°C. After removal of volatile components the remaining oil is extracted with petroleum ether (boiling range 50-70°C). On concentration of the extract ( 3 a ) and ( 3 b ) , respectively, crystallize out. Recrystallization from petroleum ether affords the analytically pure complexes.Yields: 4.50g (79 %) (3a); 0.7g (19 %) (3b).

Construction of synthetic macrocyclic compounds possessing subheterocyclic rings, specifically pyridine, furan, and thiophene

“…Vógtle and Frensch have recently described the synthesis of papaverine crown ethers. 494 IV.B.1. A series of macrocyclic compounds possessing tetrahydrofuran subunits (perhydro 204a,r,v-y) have been synthesized by an acid-catalyzed condensation of furan and carbonyl compounds followed by reduction.500 The macrocycles were shown to extract alkali metals, ammonium, and silver ions from aqueous media via the formation of a 1:1 macro-ring-metal complex with an estimated binding constant of more than 106 in chloroform.500…”