| abstract |
Enkephalin analogs I[R=H, C1-3 alkyl; R1=C1-4 alkyl, allyl, cyclopropylmethyl, C1-2 hydroxyalkyl, (CH2)mZMe(m=1, 2; Z=S, SO); R2=H, C1-4 alkyl, allyl, cylopropylmethyl; R3=H, halo, OH, C1-3 alkoxy, NO2, C1-3 alkyl, CF3; R4=CH2OR5(R5=H, C1-3 alkoxy, NO2, C1-3 alkyl, CF3; R4=CH2or5(R5=H, C1-3 alkyl), CONHR5, CO2R6(R6=C1-3 alkyl0 were prepd. as analgesics. Thus, phenylglycinamide II(BOC=Me3CO2C) was BOC-deblocked and then coupled with BOC-Phe-OH by DCC/1-hydroxybenzotriazole(HOBT) to give the protected dipeptide, which was BOC-deblocked and then coupled to BOC-Tyr-D-Ala-Gly-OH by DCC/HOBT to gove peptide III(R7=H). |