Tributylamine → Tyrosine Methyl Ester

Participants

Reaction Steps

Eighteen point two mg (0.5 mM) of hapten in 0.45 ml dry DMF was mixed with 0.0024 ml (0.1 mM) tri-n-butylamine and the solution cooled to 0° to 5°. This was followed by the addition of 0.007 ml (0.05 mM) isobutylchloroformate. The solution was allowed to react in the ice bath for 30 minutes and then was added to a cold solution of 10 mg (0.05 mM) tyrosine methyl ester hydrochloride in 3 ml 50--50 DMF-water and 0.065 ml N NaOH. Stirring in ice was continued and the solution was allowed to come to room temperature overnight, then diluted with 10 ml of water. The mixture was extracted into ethyl acetate, separated and washed twice with 10% HCL once with 10% sodium carbonate, then water and dried. The solvent was evaporated at reduced pressure and the solid residue purified by preparative TLC on a Silica Gel-60-F254-2 mm. The plate was developed with chloroform-methanol-water 25:7:1. It showed one major spot at Rt.41. This was scraped off and eluted with methanol to yield 24 mg of the desired compound.

Provenance & Evidence