133641-28-8

Upstream product

• 543-27-1 isobutyl chloroformate 
• 7432-21-5 N-carbobenzyloxy-L-tryptophane 
• 2279-15-4 N-(benzyloxycarbonyl)-D-tryptophan 

Downstream Products

• 2637-44-7 N-benzyloxycarbonyl-L-tryptophylaminoethanol 
• 1433593-67-9 Z-Trp-Phg-OH 
• 168470-53-9 2-[(R)-2-Benzyloxycarbonylamino-3-(1H-indol-3-yl)-propionylamino]-3-oxo-butyric acid ethyl ester 
• 936560-65-5 Z-(D)Trp-Lys(Boc)-Val-OMe 
• 168470-79-9 2-[(R)-1-Benzyloxycarbonylamino-2-(1H-indol-3-yl)-ethyl]-5-methyl-oxazole-4-carboxylic acid ethyl ester 
• 168470-54-0 2-[(R)-1-Benzyloxycarbonylamino-2-(1H-indol-3-yl)-ethyl]-5-methyl-1H-imidazole-4-carboxylic acid ethyl ester 
• 1026234-44-5 2-[(R)-1-{(S)-2-[(Azepane-1-carbonyl)-amino]-4-methyl-pentanoylamino}-2-(1H-indol-3-yl)-ethyl]-5-phenyl-thiazole-4-carboxylic acid ethyl ester 
• 168470-76-6 2-[(R)-1-{(S)-2-[(Azepane-1-carbonyl)-amino]-4-methyl-pentanoylamino}-2-(1H-indol-3-yl)-ethyl]-5-methyl-thiazole-4-carboxylic acid ethyl ester 
• 1028289-31-7 5-Benzyl-2-[(R)-1-benzyloxycarbonylamino-2-(1H-indol-3-yl)-ethyl]-1H-imidazole-4-carboxylic acid ethyl ester 
• 1027024-51-6 5-Benzyl-2-[(R)-1-benzyloxycarbonylamino-2-(1H-indol-3-yl)-ethyl]-thiazole-4-carboxylic acid ethyl ester 
• 1026169-47-0 2-[(R)-1-Benzyloxycarbonylamino-2-(1H-indol-3-yl)-ethyl]-5-ethyl-1H-imidazole-4-carboxylic acid ethyl ester 

Relevant academic research and scientific papers

α-N-Protected dipeptide acids: A simple and efficient synthesis via the easily accessible mixed anhydride method using free amino acids in DMSO and tetrabutylammonium hydroxide

The importance of dipeptides both in medicinal and pharmacological fields is well documented and many efforts have been made to find simple and efficient methods for their synthesis. For this reason, we have investigated the synthesis of α-N-protected dipeptide acids by reacting the easily accessible mixed anhydride of α-N-protected amino acids with free amino acids under different reaction conditions. The combination of TBA-OH and DMSO has been found to be the best to overcome the low solubility of amino acids in organic solvents. Under these experimental conditions, the homogeneous phase condensation reaction occurs rapidly and without detectable epimerization. The present method is also applicable to side-chain unprotected Tyr, Trp, Glu, and Asp but not Lys. This latter residue is able to engage two molecules of mixed anhydride giving the corresponding isotripeptide. Moreover, the applicability of this protocol for the synthesis of tri- and tetrapeptides has been tested. This approach reduces the need for protecting groups, is cost effective, scalable, and yields dipeptide acids that can be used as building blocks in the synthesis of larger peptides.

Sodium borohydride reduction of carbamoyl azide function: A synthesis of N-protected N'-formyl-gem-diaminoalkyl derivatives

A simple, efficient two-step synthesis of N-protected N′-formyl-gem- diaminoalkyl derivatives is reported. The procedure involves the unprecedented reduction of the carbamoyl azide of α-N-Boc/Fmoc/Z-protected amino acids and dipeptides (Boc = tert-butoxycarbonyl, Fmoc = 9-fluorenylmethoxycarbonyl, Z = benzyloxycarbonyl) by treatment with NaBH4 at room temperature. The reaction proceeds rapidly (45 min) without detectable epimerization (by HPLC-ESI-MS analysis) and is not influenced by the nature of the starting carbamoyl azide. The 1H and 13C NMR analyses of the synthesized N-protected N′-formamides were carried out in [D 6]DMSO. The spectra exhibited the presence of two rotameric forms in solution as a result of the restricted rotation around the N-CO formyl bond. The integration of the N-CH-N protons of the two isomers showed that the cis isomer (rotamer B) was the more abundant conformer by 60 to 78 %. The reported synthesis represents the potential value of carbamoyl azides as versatile chiral starting materials for many synthetic purposes. A simple two-step synthesis of N-protected N′-formyl-gem-diaminoalkyl derivatives is reported that employs the reduction of the carbamoyl azide of N-protected amino acids and N-protected dipeptide acids with NaBH4. This racemization-free protocol is compatible with the most commonly used N-protecting groups. Copyright

PROCESS FOR PREPARING VAPREOTIDE

A solution phase process for preparing vapreotide, having the formula:

Direct N-glycan profiling in the presence of tryptic peptides on MALDI-TOF by controlled ion enhancement and suppression upon glycan-selective derivatization

Even though the formidably laborious and time-consuming nature of oligosaccharide analysis limits certain attempts to analyze the glycosylation profile, the significant elucidation of carbohydrate modifications is largely dependent on it. Aiming to substa

Azole endothelin antagonists. 1. A receptor model explains an unusual structure-activity profile

The pseudotetrapeptide FR-139317 is a potent and highly selective antagonist of the endothelin-A (ET(A)) receptor; however, its peptidic nature leads to poor oral absorption characteristics which make it an unlikely drug candidate. In an attempt to improv

Changes in Conformation and Antimicrobial Properties Caused by Replacement of D-Amino Acids with α-Aminoisobutyric Acid in the Gramicidin Backbone: Synthesis and Circular Dichroic Studies

In an attempt to mimic the stable helical structures of proteins with possible pore-forming ability in membranes, the linear gramicidin backbone has been changed by inserting achiral α-aminoisobutyric acids (Aib) in place of all of the alternatively seque