Synthesis and opioid receptor binding properties of 17-cyclopropylmethyl-6,7-dehydro-3,14-dihydroxy-4,5 alpha-epoxy 6,7 : 4 ',5 '-pyrimidinomorphinans

A class of opioid receptor active derivatives of naltrexone has been synthe sized using a common enaminone intermediate. The intermediate used in the s ynthesis is prepared from N,N-dimethylformamide dimethyl acetal and naltrex one and can be isolated and characterized. The derivatives have heterocycli c groups fused to the 6,7-positions of the morphinan system and all were sy nthesized in high yield. All compounds were very high affinity, nonselectiv e antagonists for the opioid receptors.