Diethyl analog

This paper describes a comparison of the extraction behavior of selected. actinide(III), (IV), and (VI) ions by the dihexyl-N, N-diethyl analogs of carbamoylmethyl-phosphonate and phosphinate and octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide. 

Krapcho and Vivelo have described a new formal total synthesis of tropinone (124) and ( )-cocaine (98) (94). Cycloaddition of IV-methylpyrrole (182) and acetylenedicarboxylic acid leads to 183, which is hydrogenated to 184. The diacid mixture 184 is refluxed in MeOH/HCl to yield the diester mixture 185. Addition of this to an excess of metallic sodium in liquid ammonia at — 78°C leads to the N-methylpyrrolidine derivative 186 (cf. 95), whose diethyl analog 147 has earlier been converted to tropinone (124) and (+)-cocaine (98) (78-80) (Scheme 13). 

Figure 12. Chemical structure of clonidine (St 155) and the 2,6-diethyl-analog (St 91)...

The pyrazole 12 and its 4,4-diethyl analog have been prepared by deoxygenation of the corresponding Af-oxides with phosphorus trichloride in chloroform.52 Treatment of the azine 30 (Ar = 4-MeC6H4, Scheme 11) with hydrogen over palladium gives, as a minor byproduct (4%), the hydroxy-pyrazole 31. A radical mechanism was proposed.16... 

In conclusion, the 1,3-dithiane unit still remains among the most valuable acyl anion equivalents, although that involving methyl methylthio sulfoxide or its diethyl analog offers the definite advantages of proceeding with metal hydride or even under phase-transfer catalysis conditions and of producing the carbonyl compound under reasonably mild conditions. 

A mixture of dimethylketene-N-(p-tolyl)imine and ethyl azidoformate stirred and heated 24 hrs. at ca. 100° 4-N-(p-tolyl)imino-2-ethoxy-5,5-dimethyl-2-oxazoline. Y 70%. Also 5,5-diethyl analog s. W. J. Kauffman, J. Org. Chem. 35, 4244 (1970). 

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