Nine alkyl 2-picolyl ketones were prepared by the interaction of 2-picolyllithium and the requisite methyl ester. Physical properties were determined, and hydantoin and picrate derivatives of these ketones were prepared.
tañe with phosgene and reacting the resulting isocyanate with aniline.Prolonged Hydrogenation of 2-lsocyanatomethylbicyclo-[2.2.1 ] heptane. The above experiment was repeated, with the exception that the catalyst used was 5% palladiumon-alumina, and the reduction was continued until the hydrogen uptake decreased to a rate of less than 1 p.s.i. in two hours (Figure 1). The total quantity of hydrogen consumed was approximately 1.26 mole per mole of olefin, or 0.26 mole more than the quantity required to saturate the double bond. Following removal of the catalyst by filtration and the solvent by evaporation, the liquid residue was refined by vacuum distillation, as described above. Two liquid fractions and a solid kettle residue were obtained. Fraction 1, representing about 61% of the kettle charge, boiled from 56°to 128°C. at 1.4 to 1.0 mm. and was identified as principally the saturated isocyanate (IIIB). Fraction 2, representing about 26% of the total charge, boiled at 132°C. at 0.85 mm. (w30D, 1.5002) and was indicated by infrared spectrum (amide C=0 bands at 6.0 and 6.5 microns and an N-H at 3.05 microns) and microanalysis to be N-(2-norbornylmethyl)-formamide.
An analysis o f the ir arid nmr spectra takcn on a srrics of nine different alkyl 2-picdyl kvtones clearly indicatcLs that thi-re is an cnol-keto tautomerisni. The enol: keto ratio c-xhiliits a marhe.d dependence on hoth solvi-nt polarity and t h i b natnrcol' the alkyl group. 'I'he c~quilitirium valuc-s correlate with the 'Taft steric substititent constants.Introdiiction.
Nine 2-(2-quinoxalyl)-1-phenylethanones were synthesized by the condensation of 2-methylquinoxaline and the requisite methyl benzoate ester with sodium hydride as the condensing agent. Substituents in the 3 or 4 positions of the phenyl ring were methyl, methoxy, chloro, or trifluoromethyl.
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