Tert-butoxycarbonylation

The protecting group Y of the amine is generally an alkoxycarbonyl derivative since their nucleophilicity is low. Benzyloxy- or tert-butoxycarbonyl derivatives usually do not undergo azlactone formation. 

A related N terminal protecting group is tert butoxycarbonyl abbreviated Boc... 

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... 

Other reagents which have been found useful for the sjmthesis of t-BOC derivatives include the hazardous tert-butoxycarbonyl azide ... 

A number of less-hazardous reagents that can be substituted for tert-hutyl azidoformate in tert-butoxycarbonylation reactions are available including 2-(te/t-butoxycarbonyloxyimino)-2-phenylacetonitrile (Aldrich Chemical Company), 0-teri-hutyl N-phenyl thiocarbonate (Eastman Organic Chemicals), di-butyl dicarbonate and tert-butyl phenyl carbonate. ... 

Hydrogenation of i-butyl nicotinate methobromide, followed by hydrolysis of the 1-methyl-3-tert-butoxycarbonyl-1,4,5,6-tetrahydro-pyridine product (205) in the presence of indole affords, on decarboxylation, the -substituted derivative (206) (325). The formation of... 

Di-(2-propyl)]perhydropyrido[l, 2-c][l, 3]oxazin-l -one was lithiated with 5-BuLi in the presence of TMEDA 200 times less efficiently, than the five-membered lower homolog 3,3-[di(2-propyl)]perhydropyrido[l,2-c][l,3] oxazolin-l-one, and approximately five times more efficiently than -(tert-butoxycarbonyl)piperidine (01JA315). 

Tetrahydro-l//,5//-pyrido[3,2,l-//]quinazoline-l,3-diones were prepared by the cyclization of l-tert-butoxycarbonyl-l,2,3,4-tetrahydroqui-noline-8-carboxamide on the action of 60% aqueous NaOH solution in THF at 50 °C (01M128). 

Cyclization of l-(A -substituted aminocarbonyl)-3-[(tert-butoxycarbonyl) amino]- and -3- [Ai -(tert-butoxycarbonyl)tryptophyl]amino -2-(ethoxycar-bonylmethyl)piperidines (e.g. 188) on the action of NaH gave 2-substituted 5-(substituted amino)perhydropyrido[l,2-c]pyrimidine-l,3-diones (e.g. 159 and 189) (97JMC3402, 97MIP16, 98MI63, 0UMC2219). Cyclization could be also carried out in the presence of DBU (01JMC2219). 

B. N-(tert-Butoxycarbonyl)-fi-iodoalanine methyl ester (3). A one-necked, 250-mL, round-bottomed flask equipped with a rubber septum and magnetic stirbar is charged with 27.8 g (74.0 mmol) of N-(terC... 

The checkers purchased N-(tert-butoxycarbonyl)-L-scrinc methyl ester from Aldrich Chemical Company, Inc. The submitters prepared this compound, a thick amber oil, according to the procedure described in Dondoni, A. Perrone, D. Org. Synth. Coll. Vol. X, 2004, 320. 

N-(tert-Butoxycarbonyl)-P-4-(methoxycarbonyl)phenyl]alanine methyl ester L-Phenylalanine, N-[(l,l-dimethylethoxy)carbonyl]-4-(methoxycarbonyl)-, methyl ester (160168-19-4)... 

SYNTHESIS AND RU(II)-BINAP REDUCTION OF A KETOESTER DERIVED FROM HYDROXYPROLINE 2(S)-(p tert-BUTOXYCARBONYL-a-(S) and a-(R)-HYDROXYETHYL)-4(R)-HYDROXYPYRROLIDINE-1 -CARBOXYLIC ACID, tert-BUTYL... 

D. 2(S)-(fl-tert-Butoxycarbonyl-a-(R)-hydroxyethyl)-4-(R)-hydroxy-pyrrolidine- 1-carboxylic acid, tert-butyl ester. The identical procedure was followed, in this case using the (,S)-BINAP catalyst (5)-l. Hydrogenation is conducted for 64 hr, and the reaction mixture is then transferred to a 250-mL, round-bottomed flask and concentrated to dryness. The residue is dissolved in 17 mL of methanol and cooled to 15°C. After the slow addition of 7 mL of DI water, the solution is aged for 15 min gradually forming a thin slurry. More DI water (75 mL) is added over 1 hr and the mixture is allowed to stand for an additional 1 hr at 15°C. The resulting crystals (Note 19) are filtered at 15°C, washed with 10 mL of 1 4-MeOH water, and then dried overnight in a vacuum oven (35°C, 686 mm) to yield 7.0 g (70%) of (R)-hydroxy ester 4b (Note 20). 

S)-(P-tert-Butoxycarbonyl-a-(S)-hydroxyethyl)-4-(R)-hydroxypyrrolidine-1 -carboxylic acid, tert-... 

Dimethoxy-6-methyl-7-nitro-5-quinoxalinecarbonyl chloride (88, R = Cl) gave 2,3-dimethoxy-6A(A(-trimethyl-7-nitro-5-quinoxalinecarboxamide (88, R= NMe2) (MejNH, THE, 20°C, 19 h >95%), V-(tert-butoxycarbonyl-methyl)-2,3-dimethoxy-6-methyl-7-nitro-5-quinoxalinecarboxamide (88, R = NHCHj CO2BU ) (Bu 02CCH2NH2-HC1, EtaN, THE substrate/THEj drop-wise, N2, 5 min then 20°C, 24 h 77%), and a variety of analogs similarly. ... 

R,3S)-N-debenzoyl-N-tert-butoxycarbonyl-10-deacetyl-2-(1 -ethoxyethyl)-7,10-bis-(triethylsilyl)taxol (XXIII)... 

N -tert-butyl - 4-(tert-butoxycarbonyl)-piperazine-2(S) corbaxomide (V)... 

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