Benzyloxycarbonyl chloride

C6H5CH2OC—) IS one of the most often used ammo protecting groups It is attached by acylation of an ammo acid with benzyloxycarbonyl chloride... 

The first step is the manufacture of L-proline tert-butyl ester. L-proline (230 g) is dissolved in a mixture of water (1 ) and 5N sodium hydroxide (400 ml). The solution is chilled in an ice bath, and under vigorous stirring, 5 N sodium hydroxide (460 ml) and benzyloxycarbonyl chloride (340 ml) are added in five equal aliquots during a half-hour period. After one hour stirring at room temperature, the mixture is extracted twice with ether and acidified with concentrated hydrochloric acid. The precipitate Is filtered and dried. Yield is 442 g MP 78°C to 80°C. 

Treatment of 25 and 26, respectively, in pyridine with equimolar amounts of benzyloxycarbonyl chloride at low temperature, followed by addition of an excess of ethoxycarbonyl chloride, yielded the corresponding methyl 5-0-(benzyloxycarbonyl)-2-0-(ethoxycarbonyl)-/3-(57) and -a-D-glucofuranosidurono-6,3-lactone (58). Hydrogenolysis of the benzyloxycarbonyl group resulted in formation of methyl 2-0-(ethoxycarbonyl)-/ - (59) (70%) and -a-D-glucofuranosidurono-6,3-lactone (60) (30%), respectively, both in crystalline form. The /3-D... 

Benzyloxycarbonyl chloride [501-53-1] M 170.6, b 103 /20mm, d 1.195, n 1.5190. Commercial material is better than 95% pure and may contain some toluene, benzyl alcohol, benzyl chloride and HCl. After long storage (e.g. two years at 4°. Greenstein and Winitz [The Chemistry of the Amino Acids Vol 2, p 890, J Wiley and Sons NY, 1961] recommended that the liquid should be flushed with a stream of dry air, filtered and stored over sodium sulphate to remove CO2 and HCl which are formed by decomposition. It may further be distilled from an oil bath at a temperature below 85° because Thiel and Dent [Annalen 301 257 1898] stated that benzyloxycarbonyl chloride decarboxylates to benzyl chloride slowly at 100° and vigorously at 155°. Redistillation at higher vac below 85° yields material which shows no other peaks than those of benzyloxycarbonyl chloride by NMR spectroscopy. LACHRYMATORY. 

Lysine has two amino groups. Both amino functions are converted to amides on reaction with benzyloxycarbonyl chloride. 

Benzyloxycarbonyl chloride Dicyclohexylcarbodiimide N-Hydroxysuccinimide p-Hydroxy-D-phenylglycine Citric acid... 

Numerous applications, especially in peptide chemistry, have taken advantage of this reactivity of BTI towards amides and peptidic amides [32], Here it may be added that A-protected aminocyclopropanic amides underwent ring-opening in their reaction with BTI (two equivalents) the /i-amino amide formed was obtained quantitatively on addition of benzyloxycarbonyl chloride (Z = PhCH2OCO) [33] ... 

To prevent side reactions, the amino group of alanine must be protected to make it nonnucleophilic. In Section 24-7B, we saw that an amino acid reacts with benzyl chlo-roformate (also called benzyloxycarbonyl chloride) to form a urethane, or carbamate ester, that is easily removed at the end of the synthesis. This protecting group has been used for many years, and it has acquired several names. It is called the benzyloxycarbonyl group, the carbobenzoxy group (Cbz), or simply the Z group (abbreviated Z). 

The synthesis of the amprenavir derivative, which is equipped with a solubilizing phosphate group, takes a slightly different course from that used for the prototype. The protected intermediate 5 used in the synthesis of 12 is allowed to react with benzyloxycarbonyl chloride to provide the... 

SYNS BENZYLCARBONYL CHLORIDE BENZYL CHLOROCARBONATE pOT) BENZYL CHLOROFORMATE pop BENZYLOXYCARBONYL CHLORIDE BZCF CARBOBENZOXY CHLORIDE CARBOBENZYLOXY CHLORIDE CHLOROFORMIC ACID BENZYL ESTER... 

BENZYLOXYCARBONYL CHLORIDE see BEF500 BENZYLOXYCARBONYLGLYCINE see CBR125 N-BENZYLOXYCARBONYLGLYCINE see CBR125 5-BENZYLOXY-3-ISONIPECOTOYLINDOLE see BFC200... 

The in situ generated catalyst from ATBH and trimethyl borate has also been used in the stereoselective reduction of a-oxoketoxime ethers to prepare the corresponding chiral 1,2-amino alcohols. Thus the asymmetric borane reduction of buta-2,3-dione monoxime ether followed by acidic work-up and subsequent reaction with benzyloxycarbonyl chloride affords a 90% yield of 7V-(Z)-3-aminobutan-2-ol with excellent enantioselectivities (eq 5). A trityl group in the oxime ether is required for high enantioselectivity. This method has been successively applied to both cyclic and acyclic a-oxoketoxime ethers. 

The benzyloxycarbonates are usually prepared by treatment of the alcohol with benzyloxycarbonyl chloride in the presence of a base (DMAP or iV-ethyldiisopropylamine). Aqueous basic medium has to be avoided in polyol systems since these conditions favor the obtention... 

Catapres, Clonidine hydrochloride Cation exchange resins Cbz-Cl, benzyloxycarbonyl chloride Celite... 

PIFA easily converts succinic acid derivatives (32) to -alanine derivatives (33). Limited use of PIFA (1 equiv.) allows the rearrangement of 3-cyclohexene-1-carboxamide (34) without oxidation of the double bond, as shown in Scheme 12. Cyclohexanone is obtained by the PIFA oxidation of 1-cyclohex-enecarboxamide (35). Selective oxidation of the primary amide (36) occurs without effect on secondary or tertiary amides in the same molecule. The rearrangement of the cyclopropane derivative (37) accompanies the ring cleavage to give the -alanine derivative (38) after treatment with benzyloxycarbonyl chloride. ... 

Selective acylation was also possible with four equivalents of an arylsulphonyl chloride or an aroyl chloride furnishing 76c " and 76d, in yields up to about 50%, while the regioselective acylation fails with aliphatic acid chlorides. Reaction with benzyloxycarbonyl chloride (EtsN, MeCN, RT), however, allowed the partial protection of four hydroxy groups to yield 76e. Compounds 76c-76e (interesting as building blocks for various self-assembled structures ) may be used for further derivatizations. 

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