236. The chemistry of the pyrrocolines. Part I. 2-Methyl- and 2-phenyl-pyrrocoline

Rates of decarboxylation of the radical cations of indol-3-ylacetic acids and comparison with indolizin-1-ylacetic acids

“…Indol-3-ylacetic acid 1, 5-methoxyindol-3-ylacetic acid 2, 2methylindol-3-ylacetic acid 3, 5-methoxy-2-methylindol-3ylacetic acid 4, ethyl indol-3-ylacetate 7, 3-(indol-3-yl)propionic acid 9 and tryptophan 10 were purchased from Aldrich and used as received. Ethyl 5,6-dimethoxy-2-methylindol-3-ylacetate 5, 9 1-methylindol-3-ylacetic acid 6, 11 1,2-dimethylindol-3-ylacetic acid 8, 12 3-acetyl-2-methylindolizine 19, 13 1,2-dimethylindolizine 20 14 and 3-benzoyl-2-phenylindolizine 21, 13 were prepared as described. Experimental procedures to obtain melting points, spectroscopic data, elemental analyses and chromatographic separations were as described.…”

“…Substitution by ethoxycarbonylcarbene was used to obtain the ethyl acetates. A solution of ethyl diazoacetate (0.069 mol dm Ϫ3 ) in benzene (100 ml) was added dropwise to a boiling solution of indolizine 19, 13 20 22 or 21 13 (0.018 mol dm Ϫ3 ) in benzene (100 ml) containing a catalytic quantity of copper() chloride. After cooling, the solid was removed, the solvent evaporated and the residue purified by column chromatography (silica gel, ethyl acetate-light petroleum).…”

Regioselective synthesis of 3-acylindolizines and benzo- analogues via 1,3-dipolar cycloadditions of N-ylides with maleic anhydride

“…It is noteworthy that, among the more general synthesis of benzo-indolizines, the Tschitschibabin reaction can not be used for the synthesis of pyrrolo[1,2-a]quinoline derivatives because the reaction of 2-methylquinoline with either phenacyl bromide or a-chloroacetate gives merely the corresponding 2methylquinoline hydrohalide. 34 Although several syntheses of pyrrolo[1,2-a]quinolines have been reported, 11 more general and convenient one pot synthetic methods are still needed. Our results and other recent reports 11b,17a,d showed that, [3+2] cycloaddition of the N-ylide with electron deficient alkenes in the presence of TPCD serves as a convenient and regioselective one pot synthesis of pyrrolo[1,2-a]quinoline derivatives, and these 1,3dipolar cycloadditions with maleic anhydride as a dipolarophile turned out to be a general regioselective synthetic approach to the 1-acylpyrrolo[1,2-a]quinolines.…”

Synthesis and Characterization of Some 3-Nitroso-2-arylimidazo (1,2-α) pyrimidines

“…Nitrosation of 2-Phenylimidazo( 1,2-a)pyrimidine-Nitrosation of 2-phenylimidazo( 1,2-a)pyrimidine has not previously been reported. Since procedures have been reported for nitrosation of 2-phenylimidazo( 1,Za)pyridine (5-7) and 2-phenylindolizine (2-phenylpyrrocoline) (8,9), the probability of success was considered favorable. Although some difficulties were enco~ntered,~ fine emerald-green needles were obtained according to the following procedure, a modification of the procedure of Pentimalli and Bozzini (7).…”

“…sweep tune, sensitivity of 400, time constant of 1 sec., and power of5 x 103. 8 N,N-bis-(2-chloroethyl)arylglyoxylohydroxamamides. The present project was begun as an attempt to prepare the similar N-2-pyrimidinylarylglyoxylohydroxamamides from a condensation of arylglyoxylohydroxamyl chlorides with 2-aminopyrimidine.…”