TBoc

Fig. 18. Chemistry of PTBOCST chemically amplified resist. Pattemwise exposure creates small quantities of acid. In a subsequent heating step, pendant TBOC groups are cleaved under acid catalysis. The exposed and unexposed areas can then be differentiated on the basis of solubiUty.

With respect to the monoazacrown ethers, Pedersen has utilized some interesting technology which is applicable to this class of compounds. For example, he has used benzylamine as a nitrogen transfer agent. This is accomplished by the sequence shown in Eq. (4.5). In the same report, Pedersen utilized the r-butyloxycarbonyl (tBOC)... 

Figure 8. Simultaneous measurement of intracellular Ca and oxidant production in neutrophils. Cells were labeled with Quin-2 and suspended at 2 x lo cells/mL buffer. At time zero, 1 nJf FLPEP was added (upper trace in each panel). In addition, the receptor blocker tBOC was added (3 x 10" M) after 30 s to stop further binding of the stimulus (lower trace in each panel). The excitation wavelength was 3A0 nm. Top panel Quin-2 fluorescence determined on channel B (of Figure 1) using a Corion A90-nm interference filter. The crossover from the superoxide assay has been subtracted. Middle panel Oxidant production (superoxide equivalents) determined by the para-hydroxyphenylacetate assay. Fluorescence was observed at AOO nm (on channel A of Figure 1).

The slowly dissociating state appears to reflect receptor in an inactive form. Cells can be stimulated in a pulse protocol in which the stimulus (FLPEP) is added, then at some later time, its binding to the receptor is interrupted by the addition of an antibody to fluorescein or of a receptor antagonist (tBoc-phe-leu-phe-leu-phe). 

Figure 4 shows an analysis of binding and dissociation of FLPEP in permeabilized cells in the absence (top panel) and the presence of GTPyS (lower panel). Dissociation is initiated, as indicated, by the addition of a receptor antagonist, tBoc-phe-leu-phe-leu-phe. The solid line is a fit to the data. The data from this experiment have... 

Tertiarybutoxycarbonyl (tboc) derivative of 3-phenyl-2-amino-l-propanol... 

The diffusion of entrapped guest molecules out of dendritic boxes was un-measurably slow over a period of several months. However, Meijer and coworkers have demonstrated that the shape-selective liberation of encapsulated guests could be achieved by removing the closed shell in two steps (Scheme 3) [15]. First, hydrolysis of the tBOC groups of the dense shell with formic acid gave a partly open dendritic box . At this point, small guests such as p-nitroben-zoic acid and nitrophenol could diffuse out of the box by dialysis. Susequent and complete removal of the outer shell by refluxing with 12 AT HC1, lead to the... 

Amino group protection may be achieved by converting the amine into its Al-tert-butyloxycarbonyl (tBOC or just BOC) derivative, by reaction with di-tert-butyl dicarbonate. This reagent should be considered as a variant of a carboxylic acid... 

The resin-bound perfluoroalkylsulfonyl linker is compatible with many common solid-phase reactions, such as tin dichloride-mediated aromatic nitro group reduction, trifluoroacetic acid-mediated tBoc deprotection, reductive amination reactions, acylation, and sulfonation. It is possible to perform several sequential synthetic reactions on the nonflate resin so that multistep syntheses can be carried out. The solid-phase approach provides an operationally simple, inexpensive, and general protocol for the cleavage... 

The appropriate pam resin (tBoc-aminoacyl-(4-carboxyamidomethyl)-benzylester-poly-(styrene-l% divinylbenzene), where the aminoacyl group is the protected C-terminal amino acid corresponding to the C-terminal residue in the chemokine to be synthesized. 

Remove the Na tBoc group from the NH2-terminal residue, using the deprotection and neutralization steps that have been described in Subheading 3.1. 

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