Quinoline reaction with, phosgene

Barton devised a new method for the oxidation of primary alcohols to aldehydes involving in the first step conversion to the alkyl chloroformate (1) by adding a solution of the alcohol in ether to ether saturated with phosgene (15-20% w./v.) the solvent is removed at reduced pressure. If the alcohol is hindered, quinoline is added as catalyst and the quinoline hydrochloride removed by filtration. The next step, reaction with dimethyl sulfoxide, is attended with evolution of carbon... 

The preparation of berbines (Scheme 38) through treatment of 1-benzyl-1,2,3,4-tetrahydro-iso-quinolines with phosgene gas to yield the iV-chloroformyl derivatives (208) is another example of the use of intramolecular Friedel-Crafts reactions in the construction of quinolizidine systems. These intermediates gave berbin-8-ones (209) by intramolecular ring closure in the presence of several Lewis acid catalysts (Scheme 38) <85T169>. 

Preparative Methods The title reagent is prepared by reaction of (IR, 2S)-2-phenyl-l-cyclohexanol with excess phosgene in the presence of quinoline to afford a chloroformate which is treated directly with hydrazine monohydrate (0.5 equiv) to afford di-(—)-(IR, 25)-2-phenyl- 1-cyclohexyl diazanedicarboxy-late. Oxidation of the diazanedicarboxylate to the diazenedicarboxylate is then readily effected using N-bromosuccinimide and pyridine (eq 1). 

This material is preferabiy prepared, with the label in a different position, from the reaction of quinoline with CH 3 CH jOCOCl [1725]. This is itself prepared by the reaction of specifically labelled ethanol with unlabelled phosgene ... 

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