Butoxycarbonyl protecting group

Hydrogen bromide may be used to remove either the benzyloxycarbonyl or tert butoxycarbonyl protecting group The benzyloxycarbonyl protect mg group may also be removed by catalytic hydrogenolysis... 

Ester group of l-(ethoxycarbonylmethyl)-7-aryl-5-oxo-1,2,3,5-tetrahydro-pyrido[l,2,3-i/e]quinoxaline-6-carboxamides was hydrolyzed and the 1-carboxymethyl moiety was converted to an aminocarbonylmethyl group with 1-methylpiperazine (01MIP12). Bromo atom of l-(2-bromoacetyl) derivatives was substituted by different amines. An amino group in the side chain attached to the position 1 of 7-aryl-5-oxo-l,2,3,5-tetrahydropyr-ido[l,2,3-i/e]quinoxaline-6-carboxamides was acylated, and terc-butoxycarbonyl protecting group of amino group was eliminated. 

Yamashiro et al. 1972), boron trifluoride etherate in acetic acid (Schnabel et al. 1971), trimethylsylil triflate (Schmidt et al. 1987), trimethylsilyl perchlorate (Vorbrueggen Krolikiewicz 1975), and, most frequently, trifluoroacetic acid (Farowicki Kocienski 1995 and references therein). Deprotection of the /-HOC group under neutral conditions was not described until recently, yet it is highly desirable. Now it has been found that the tert-butoxycarbonyl protecting group for amines, alcohols, or thiols is removed efficiently (90-99% yield) with use of 0.2 equivalent of cerium ammonium nitrate in acetonitrile at 80°C (Hwu et al. 1996) ... 

Note Boc, -butoxycarbonyl, protecting group is stable to the reaction conditions in Steps 1-6.)... 

Other peptides in the Fcycto-MRF-NH2 series have been prepared using a more acid stable resin (MBHA, methoxybenzhydry-lamine) and Boc (t-butoxycarbonyl) protecting groups, but the Fmoc approach above gives superior yields. ... 

For example, the fcrt-butoxycarbonyl protecting group, abbreviated as Boc, is formed by reacting the amino acid with di-tert-butyl dicarbonate in a nucleophilic acyl substitution reaction. 

The N-tert-butoxycarbonyl protecting group of substituted pyrroles can be removed readily by methoxide ion or, when electron-withdrawing substituents are present, by mild thermolysis.6... 

Butanetetraol, 38 r-Butoxycarbonyl protecting groups, 47.417 p-r-Butylcalixarenes, 80 p-r-Butylphenol, 80... 

Convenient removal of the N-teit-butoxycarbonyl protecting group in hydrogenated phenanthridine derivatives such as 284 is achieved without double bond isomerization by FVP at 650 °C (Scheme 57). The isomeric compounds shown in Scheme 57 can also be formed clearly from their respective Boc derivatives in this way, in contrast to conventional deprotection using trifluoroacetic acid which results in double bond isomerization (2009SL1587). 

As the synthesis was finally developed a r rr-butoxycarbonyl-protecting group (tBoc), was sufficiently acid stable to permit diazotization of the aniline. In model reactions coupling occurred predominantly para to the activating phenoxide, so... 

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