131326-21-1Relevant articles and documents
USE OF 4-CHLOROBUTYL ESTERS IN PEPTIDE SYNTHESIS
Trigo, M. Joaquina S. A. Amaral,Santos, M. Isabel A. Oliveira
, p. 2357 - 2359 (2007/10/02)
Ho and Wong synthesised 4-chlorobutyl esters of simple carboxylic acids and removed the ester group by the action of sodium sulfide under reflux conditions.We describe here the synthesis of the 4-chlorobutyl esters of glycine and L-phenylalanine and its use in the synthesis of six new N-protected dipeptides 4-chlorobutyl esters (XHNCH2CO-HNCHRCO2(CH2)4Cl; R = H, CH2Ph; X = Z, Boc, Trt).The selective removal of the 4-chlorobutyl group can be achieved by the action of the sulfide anion in aqueous acetonitrile (room temperature, 1.5 to 5 h).The conditions are milder than those described, but similar to the conditions used with the dipeptides 2-bromoethyl esters.The N-protected dipeptides were isolated in 50 to 80percent yield.