No abstract

CsHnONSa 41.17 41.45 4.75 5.07 47 c,h7 90.5-91.5 31' C»H13OXS3 43.69 44.01 5.30 5.47 64 (CH3)2CH 112-112.5 21 c,h13oxs3 4.3.69 44.03 5.30 5.38 49 C,H, 106.5-107.5 44d C10H15ONS3 45.94 46.03 5.78 5.42 15 (CH3)2CH-ch2 112-112.5

No abstract

The preparation of 2-cyclopentene-1-glycine has been effected by condensation of 3-chlorocyclopenteiic R ith either acetamido-or formamidomalonic ester followed by the usual acid hydrolysis and decarboxylation. Attempts to prepare the amino acid from the condensation product of cyanoacetic ester and 3-chlorocyclopentene by the Curtius method of amino acid synthesis resulted in the formation of 2-(2-cyclopentyl)-hydantoic acid. 2-Cyclopentene-1-glycine is a potent growth inhibitor for Escherichia coli, and a mixture of valine and isoleucine but neither alone prevents the inhibition in a competitive manner.Cyclopentaneglycine has been reported to inhibit competitively the utilization of isoleucine in Escherichia coli.2 The cyclopentyl group apparently is structurally more similar to the sec-butyl group than to either the isopropyl or isobutyl group since this amino acid analog prevents the utilization of isoleucine rather than valine or leucine.In order to compare the effect of a cyclopentene ring with that of a cyclopentane ring, the preparation of 2-cyclopentene-1-glycine was undertaken in this investigation. Condensation of 3-chlorocyclopentene, from cyclopentadiene and hydrogen chloride, with either acetamido-or formamidomalonic ester resulted in the formation of the substituted derivative I which on hydrolysis gave the desired product 11. COOEtIn subsequent experiments, acetamidomalonic ester was condensed with the halide to obtain the intermediate, a-acetamido-2-cyclopentene-1-malonic ester, in crystalline form. Hydrolysis of this intermediate with dilute instead of concentrated hydrochloric acid resulted in the formation of no more than a trace of the contaminating material giving a purple coloration with ninhydrin reagent. Thus, the cyclopenteneglycine could be purified by fractional crystallization without an intermediate step involving chromatoqraphy on Polycel.During the course of the above synthetic work, other possible synthetic rnutes were studied in order to avoid the tedious separation by chromatography of the mixture obtained in the initial experiments with formamidomalonic ester. One of these methods involved the Curtius reaction for COOH COOH COOEt I I V 1'In initial experiments, in which formamidomalonic ester was condensed with 3-chlorocyclopentene, the intermediate was not isolated but hydrolyzed directly with concentrated hydrochloric acid. Such a procedure resulted in the formation of a mixture of two components, only one of which was inhibitory to the growth of E. coli. Paper chromatograms of the mixture using 9570 methanol as the solvent for ascending development gave upon treatment with ninhydrin reagent a yellow spot, Rf 0.59, and a purple spot, Rr 0.65. Bioautographs with E . coli showed an inhibition zone corresponding to the position of the yellow spot developed with the ninhydrin reagent. Separation of the two components was effected by chromatographing the mixture on Polycel in 1-butanol saturated with water.(1) (a) In part from a thesis submitted by Robert L. Dennis to the Graduate...

The interaction of certain Grignard reagents with 4-morpholineacetonitrile, a-methyl-4-morpholineacetonitrile and a.adimethyl-4-morpholineacetonitrile has been studied.