Sarcosine anhydride

Sarcosine anhydride [5076-82-4] M 142.2, m 146-147 , pK s ( )-from water, EtOH or ethyl acetate. Dried in vacuum at room temperature. 

Not surprisingly, the diacid 13 and its diamide are waterlogged with 2-4 molecules of HzO from which they are difficult to liberate. Binding experiments in CHC13, a non-competing solvent, revealed that stoichiometric complexes, e.g. 48 were formed with diketopiperazines 40) (Kh 104) and amides such as malonamide. With structures of inadequate hydrogen bonding capacity, such as sarcosine anhydride, com-plexation does not occur. 

Williams and Rastetter also accomplished an elegant synthesis of ( )-hyalodendrin (83) in 1980 [39]. Beginning with the sarcosine anhydride-derived enolic aldehyde 78, silyl protection of the enal enabled alkylation of the glycine center with benzyl bromide and thiolation using LDA and monoclinic sulfur a la Schmidt. After protection of the thiol with methylsulfenyl chloride and deprotection of the silyl ether, the enol was sulfenylated with triphenylmethyl chlorodisulfide to afford bis(disulfide) 82 as a 2 1 mixture of diastereomers favoring the anti isomer. Reduction of the disulfides with sodium borohydride and oxidation with KI3 in pyridine afforded ( )-hyalodendrin (83) in 29 % yield (Scheme 9.4). 

Traces of water have no effect upon the rate of the reaction. This was demonstrated by changing the method of drying of LiCl and by deliberate addition of small amounts of water to the system containing dry LiCl. In this respect a very different behaviour is shown by the N-substituted NCA s, e. g. the sarcosine anhydride. Although its solution in dimethyl formamide does not react in the presence of dry LiCl, a fast reaction ensues on addition of traces of water. This is again a strong evidence for different mechanisms of initiation and, probably also, of propagation for the non-N-substituted and the N-substituted NCA s... 

Table 3.1. Rate constants for the reaction of cysteamine thiyi radicals with model peptides in D2O, pD 3.0-3.4 at 37 °C (adapted from Ref [84] abbreviations for the diketopiperazines SarcA = sarcosine anhydride, Gly = glycine anhydride).

J. W. Poole and T. Higuchi, Complexes formed in aqueous solutions by sarcosine anhydride interactions with organic acids, phenols, and aromatic alcohols, J. Am. Pharm. Assoc., 1959, 48, 592-601. 

Sarcosin anhydride ( C H,oOgNa ) + Resacetophe-none ( CeHgOs )... 

Sarcosin anhydride phenone ( C,aH,oOa Pfeiffer and Wang, ( C HioOgWa ) 1927 ) + 2,5-Dloxybenzo-... 

Sarcosin anhydride ( 0O3N2 ) + p-Toluic acid ( CgHgOg )... 

Sarcosin anhydride ( CsHio OgNg ) + Anthranilic acid ... 

---