g 100 1 0 carboxylic acid amide valeroyl chloride 120 6 13 3 g 13 0 ml 110 1 1 triethyl amine 101 2 13 2 g 18 1 ml 130 1 3 thf total 100 ml 21 2 g 1 aminocyclopentane carboxylic acid amide was suspended in a mixture of dry thf 80 ml and et 3 n and cooled to 10 u00b0 c a solution of valeroyl chloride in thf 20 ml was slowly added with vigorous preferably mechanical stirring the reaction temperature was kept below 30 u00b0 c and the resulted suspension was vigorously stirred for 1 h at room temperature tlc monitoring ch 2 cl 2 meoh 8 1 the solvent was evaporated under reduced pressure and the white residue was suspended in water 200 ml and stirred for 20 min at room temperature the solid was filtered washed two times with water total 100 ml and methyl t butyl ether 30 ml and dried at 50 u00b0 c 10 mmhg until constant weight to give 18 5 g 87 3 yield of irb 23 as a white powder pure by nmr this product was used without additional purification having thus described the invention with reference to particular preferred embodiments and illustrative examples those in the art can appreciate modifications to the invention as described and illustrated that do not depart from the spirit and scope of the invention as disclosed in the specification the examples are set forth to aid in understanding the invention but are not intended to and should not be construed to limit.