common protection group

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Amine:

9-Fluorenylmethyl Carbamate (Fmoc)	Fmoc has very good stability in acidic condition, and reasonable stability in inorganic base. It could be removed in a couple minutes with piperidine. You can see a very bright blue spot on your TLC solvent front line.
t-Butyl Carbamate (Boc)	Boc is used extensively in amine protection. It is stable under base condition, could be easily get rid of under TFA/CH₂Cl₂(1/1). Boc could be reduced to methyl group under LAH to make single methyl substitution.
Benzyl Carbamate (Cbz or Z)	Cbz is another popular carbamate used in the amine protection. It could be easily deprotected under hydrogenation or triethyl silane.
Formadide
N-Phthalimide	Gabriel Amine synthesis is similar to this protection, go figure out the rest of the mechanism.
N-2,5-Dimethylpyrrole	Dimethyl Pyrrole protection is very useful in primary amine protection, especially you could not have active proton in your molecule.
N-Benzylamine
N-Triphenylmethylamine
Demethylation form amine	Very beautiful deprotection method.

Alcohol:

	Methyl protection is easy to put on , but difficult to get rid of.
	Iressa, a cancer drug from AstrazZeneca, was made from this demethylation
	Selective demethylation was done by using ethyl thiol (very stink) and AlCl3.
	MOM, MTM
	BOM
	t-Bu

Lab rat's protection and deprotection procedure:

Benzyl chlorofomate amine protection: Amine ( 1equiv.) and TEA (2 equiv.) were dissloved into THF. To the solution, benzyl chloroformate was added dropwise. The resulting mixture was stirred for 4 hours. The precipitate was filtered. Ethyl acetate was added into the organic solution. Brine was used to wash the organic layer. The organic layer was dried, concentrated. The resulting residue was separated by silica gel column to afford 90% yield.
Boc protection of amine group: Amine (1equiv.) and Boc₂O (1.5 equiv.) were dissolved into methylene chloride with TEA(2 equiv.). The mixture was stirred for 6 hours at room temperature. The resulting mixture was washed with brine, and the organic layer was dried and concentrated. The resulting residue was separated by silica gel column.
Benzyl protection of phenol. The starting material, phenol (1 equiv.), was dissolved into acetone. BnBr (1.3 equiv.), and K2CO3 (15 equiv.) were added into the acetone solution. The resulting mixture was refluxed for 2 hours. After filtered the solid, the filtrate was concentrated, and the residue was separated by a silica gel plug.
DeBoc of amine: The starting materials was dissolved into CH2Cl2/TFA (1:1). The mixture was stirred for 4 hours at room temperature. The resulting mixture was concentrated. The resulting residue was taken into ethyl acetate, and neutralized with base. The resulting mixture was washed with brine, and concentrated. Most likely, the crude sample is pure enough for next reaction.
Deprotection of Fmoc group: The starting material was dissolved into THF with piperidine or morphline. The mixture was stirred for 1 hour at room temperature. The TLC showed a very blue spot in the front line, and no starting material had left. The mixture was charge to a silica gel plug, washed with hexane/ethyl acetate to give 95% desired product.
Deprotection of benzyl group: The starting material was dissolved into ethanol with Pd on C. The mixture was put on parr shaker with H₂ 30 psi for 3 hours. The resulting mixture was filtered, and the filtrate was concentrated to afford almost pure product.
Demethylation of tertiary amine: To the dichloroethane solution of tertiary amine (1 equiv.), was added 1-chloroethyl chloroformate (3 equiv.) dropwise. You should see some bubble if you have a reasonable scale of reaction, otherwise base is need to quench the HCl from chloroformate decomposing. The mixture was stirred for 10 min at 0oC, and then stirred for another 20 min at room temperature. The mixture was concentrated under vacuo. The resulting mixture was dissolved into methanol and refluxed for 20 min. You should notice a lot of gas was released. Water was added into the mixture, and the resulting mixture was stirred for another 20 min at room temperature. Ethyl acetate was used to extract the product from water. The organic layer was dried, concentrated, and the residue was separated by silica gel column to give 90% desired product.
Demethylation of methyl phenol. The starting material, methyl phenol (1 equiv.) was dissolved into toluene, and AlCl3 (BBr3 also could do the work) (3 equiv.) was added slowly. The resulting mixture was heated to reflux for 4 hours. The resulting mixture was cool to room temperature and dump into ice-water. More ethyl acetate was used to extract the product from water. This procedure fits to simple methyl phenol. HSCH2CH3, very stinky chemical, was used to do demethylation with AlCl3. Lab rat used HSCH2COOH instead of HSCH2CH3 once also achieved reasonable yield, but much less stinky.