EDCI, 1 -ethyl-3-

Ill was prepared by condensation of ethylbromopyruvate with thioamide 110. Utilizing these oxazole and thiazole derivatives, sequential couplings of 109 and 111 and then 112 and 113 with EDCI-N-hydroxybenzotriazole (HOBt) (EDCI, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide) in basic medium afforded the linear precursor 114. Deprotection followed by macrolactamization with FDPP/DIPEA afforded dendroamide A 106 in 91% yield. 

BuOH, EDCI (EDCI = l-ethyl-3-[3-(dimethylamino)propyl]carbodi-imide hydrochloride), DMAP, CH2CI2, 88% yield.Cbz-Proline was protected without racemization. 

Boc-D-alanine and (S)-a-methylbenzylamine react to give the corresponding dipep tide via an EDCI [3-ethyl-l-(3-dimethylaminopropyl)-carbodiimid] coupling [86], control experiment, Boc-t-alanine and (S)-a-methylbenzylamine also reacted. 

The reaction of methyl 10, l l -dihydropyrrolo[ l, Z-b [ l, 2,5]bcnzothiadiazcpinc-l l -acetate 5,5-dioxide 73 or the corresponding ethyl ester 74 with potassium hydroxide in EtOH at 25 °C gave the acid 75 (Scheme 14), which upon treatment with trifluoroacetic anhydride in tetrahydrofuran (THF) underwent intramolecular cyclization to afford 76. The 1,2,5-thiadiazepines 73 and 74 were then heated with an excess of concentrated ammonium hydroxide to give the carboxamide 77. The acid 75 upon reaction with 4-chlorophenol, 4-chlorobenzyl alcohol, or 4-chloroaniline in the presence of iV-(3-dimethylaminopropyl)-iV -ethylcarbodiimide hydrochloride (EDCI) and 4-dimethylaminopyridine (DMAP) afforded the respective esters and amide 78-80 <1996FES425>. 

Eledroosmotic flow (EOF) conditions were applied and yielded only 10% conversion with constant reactant movement [9]. The use of stopped-flow techniques, which periodically push and mix the flow, led to a 50% increase in yield. A change in the coupling agent from l-(3-dimethylaminopropyl)-3-ethyl-carbodiimide hydrochloride (EDCI) to dicyclohexylcarbodiimide (DCC) for reasons of limited solubility resulted in a 93% yield of the dipeptide. Batch P-dipeptide synthesis using EDCI gave a yield of 50% [6]. 

Well established carbodiimide-based methods for esterifying carboxylic acids can be used to prepare te/7-butyl esters. In the example shown in Scheme 638, dicydohexylcarbodiimide (DCC) served as the dehydrating agent,94 but 1-ethyl-3-[3-dimethylamino)propyl]carbodiimide (EDCI) works equally well and the by-product urea is water soluble in the latter case 95... 

EDCI N-ethyl-lV -(3-dimethylaminopropyl)carbodiimide HOBt 1-hydroxy-l//-benzotriazole LDA lithium diisopropylamide... 

Polystyrene-supported tethered l-ethyl-3-(3-dimethylamino-propyl)carbodiimide hydrochloride (PS-EDC or PS-EDCI, 11) is also a commercially available, frequently used resin-supported carbodiimide [25], which is highly effective in the coupling of carboxylic acids and amines, in the absence of any additive the use of chloroform as solvent is essential. 

Miller, M.M. and Boger, D.S. (2005) Polystyrene-1-ethyl-3-(3 -dimethylaminopropanej-carbodiimide Hydrochloride (PS-EDCI), in Handbook of Reagents for Organic Synthesis, Reagents for Glycoside, Nucleotide and Peptide Synthesis (ed. D. Crich), John Wiley Sons Ltd, Chichester, pp. 529-33. 

EDCI l-ethyl-3-[3-(dimethyl-amino)propyl]carbo-diimide hydrochloride... 

---