T-butyloxycarbonyl

Bmnauer-Emmett-TeUer (adsorption equation) twice daily t-butyloxycarbonyl biochemical (biological) oxygen demand boiling point becquerel... 

Each racemate was applied on a polymer (ca. 0.1. imol per gram dry polymer) imprinted with one antipode of the racemate. Tlie standard mobile phase, consisting of acetonitrile containing various amounts of acetic acid, was used in most cases. Cbz = Carbobenzyloxy, Boc = t-butyloxycarbonyl. 

Cyclization of 1 -[.V- 2.2-bis(/ t )-butyloxycarbonyl)cthyl -./V-mcthylamino]-5,6,7,8-tetrafluoro-4-oxol, 4-dihydroquin-... 

Ito and coworkers (86-87) recently described a new DUV resist system that has high sensitivity, does not suffer swelling during development, and may be used either as a positive or negative system. The new resist is based on a formulation consisting of t-butyloxycarbonyl (t-BOC) protected poly(vinylphenol) 88 (Figure 50) and an onium salt sensitizer. Exposure... 

Halotriazoles can act as halogenating agents and A-acyltriazoles can act as acyl transfer reagents. Triazole can be used for the synthesis of peptide bonds and is superior to imidazole in that less racemization is observed. It can also be used to transfer the t-butyloxycarbonyl (t-Boc) protecting group to the nitrogen of amino acids. For details see Polya <84CHEC-I(5)733, p. 786). 

Figure 11.19 (a) Stracture of a hydrophilic fifth-generation poly(propylene imine) dendron containing a focal hydrophobic polystyrene block, (b) Stracture of a fourth-generation t-butyloxycarbonyl (Boc)-protected polylysine dendron having a focal poly(ethylene glycol) chain. 

The direct synthesis of the parent cycloadduct (251 R = R = H) is not feasible from pyrrole and benzyne, but it may be obtained in good yield via the N-t-butyloxycarbonyl derivative or, preferably, from 1-trimethylsilylpyrrole (77JHC213). 

The two commonest examples are the benzyl carbamates (CBZ derivatives) (4) and the t-butyl carbamates (BOC derivatives) (5) where the amino group is protected by the benzyloxycarbonyl or the t-butyloxycarbonyl groups respectively. 

The conversion of the amino group in amino acids into a t-butyloxycarbonyl group is a process which is widely used in automated peptide synthesis carried out on solid (polymeric) supports (solid phase synthesis the Merrifield technique).230... 

Alternatively, acylation with di-t-butyl pyrocarbonate233 has been recommended as a general procedure for the preparation of t-butyloxycarbonyl amino acids.234... 

This particular feature of P-N bond containing compounds can be utilized for synthetic purposes by using "phosphoryl protection" in the synthesis of amines based on alkylative procedures. The solution of this problem introducing two new reagents, i.e. diphenyl-phosphinic amide (I) and sodium N-(t-butyloxycarbonyl) diethyl phosphoroamidate (II) as useful synthetic equivalents of an amino moiety is the subject of this communication. 

Phase-transfer catalysed N-alkylation of diphenylphosphinic amide (I) is totally unsuitable in the case of easily hydrolysable organic halides, especially those containing additional functional groups (i.e. carbonyl or carboalkoxyl) which decompose readily in strongly alkaline medium. To circumvent the difficulty connected with simultaneous mono- and dialkylation of (I) under anhydrous conditions, N-(t-butyloxycarbonyl) diethyl phosphoroamidate (X), a doubly-protected ammonia derivative, was devised as a useful and superior substitute of phthalimide in the Gabriel-type synthesis of amines. 

A close relative to Cbz is Boc (t-butyloxycarbonyl) that uses a different method to make esters easy to hydrolyse. It is added to an amine or an alcohol by the chloroformate 46 and, after the reaction, hydrolysed with acid—no water being needed. The ester is protonated and the t-butyl cation drops out in an Sn 1 reaction 49 to give the same intermediate 36 as in the removal of the Cbz group. 

N-t-Butyloxycarbonyl-p-alanine 2,4,5-trichlorophenyl ester Manufacturing Process... 

The starting material in the following synthesis is t-butyloxycarbonyl-L-aspartyl-L-tyrosyl-L-methionylglycyl-L-tryptophyl-L-methionyl-L-aspartyl-L-phenylalanine amide designated (SM). 

X amino-protecting group (e.g. t-butyloxycarbonyl) Y activating group (e.g. —N3, —C6H4-p-N02,... 

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