Is water your only solvent? In many cases, hydrolysis of acetyl protecting groups is accelerated in the presence of methanol or ethanol co-solvent. The transiently generated alkoxide ions are more nucleophilic than hydroxide, plus organic co-solvents can improve the solubility of reactants. Here are some readily accessible options:

• 4 M LiOH (aq) in methanol or ethanol (1:3 volume/volume), rt, monitor by TLC, HPLC, LC-MS, or GC-MS

• 4 M K2CO3 (aq) in methanol or ethanol (1:3 volume/volume), rt, monitor by TLC, HPLC, LC-MS, or GC-MS

• Either of the above aqueous bases in THF or 1,4-dioxane (1:3 volume/volume), rt, monitor by TLC, HPLC, LC-MS, or GC-MS

If you don't have access to SciFinder or Beilstein, it may be helpful to obtain a copy of Protecting Groups (2005) by Philip Kocieński as a general reference. Hope this helps.  

Hi Timea,

Well, depending on what your "nitrogen" looks like, this can be easy, or it can be more difficult... Lael above provided some good typical examples, I just mention a couple things. Sometimes the carbonyl group of the trichloroacetamide is involved in additional interactions with, say, a distal hydroxyl group, which may be stabilizing the orthoester form, and that way it is inert to some reagents. Or the carbonyl is very hindered due to the presence of bulky moieties in vicinity.

Sometimes people use DIBALH reduction (or another hydride reduction) to accomplish this deprotection (e.g. J. Org. Chem. 2012, 6051), or they use ethylenediamine. Two very typical procedures, as applied for small molecule (M.W. < ca. 300) amine trichloroactamides are as follows. Good luck.

Ex. 1:

N-(1,1-Dimethyl-2-propenyl)amine hydrochloride: To a solution of N-(1,1-dimethyl-2-propenyl)-2,2,2-trichloroacetamide (390 mg, 1.69 mmol) in EtOH (9.0 mL) was added a solution of NaOH aq. (6 M, 8.5 mL, 51 mmol). After 18 hr the solution was extracted with ether (3 x 30 mL) and the combined organic layers were washed with brine (20 mL), dried over Na2SO4 (a small amount of MgSO4 was added to clarify the solution) and filtered. The filter cake was washed with ether (15 mL) and the filtrate was acidified by bubbling HCl (g) through the solution for 6 min. The resulting suspension was concentrated in vacuo and washed with benzene to afford 200 mg of pure aminehydrochloride salt 26b in 97 % yield.

Ex. 2:

(S)-Benzyl hex-1-en-3-ylcarbamate. 4 A mixture of (S)-trichloroacetamide 2a (4.80 g, 0.0196 mol, 87.8% ee), methanol (125 mL) and 3N sodium hydroxide solution (35 mL) were warmed up to 50 °C, and the reaction maintained at this temperature for 24 hours. The reaction was monitored by TLC (10% ethyl acetate/petroleumether). After the starting material had disappeared, the reaction was acidified with 2N HCl (82.5 mL). Methanol was evaporated under reduced pressure, and then the residue was washed with CH2Cl2 (2 × 20 mL). The acidic solution was cooled to 0 °C, and then 20% sodium hydroxide solution (24 g) was added until pH paper indicated 14. The product was extracted with diethyl ether (3 × 25 mL), then the combined organic phase was dried with potassium carbonate. Removal of the solvent under reduced pressure at around 0 °C gave (S)- 3-hex-1-enylamine as a 32.2% w/w solution in ether (determined by 1H NMR) (4.6 g, net 1.5 g, 77% yield).This ether solution was used to the next reaction. 1H NMR (400MHz, CDCl3); 5.78 (1H, ddd, J = 16.8, 10.4, 6.4 Hz), 5.09 (1H, dd, J = 17.6, 1.6), 4.99 (1H, dd, J = 10.8, 1.6), 3.22-3.32 (1H, m), 1.12-1.42 (4H, m), 0.92 (3H, t, J = 7.6 Hz).

From Greene's Protective Groups (2007):

NaBH4, EtOH, 1hr - Frauendorfer, Chem Ber, 103, 2437 (1970)

Cs2CO3, DMF or DMSO - Isobe, Tet Lett, 45, 9405 (2005)

See

https://books.google.cz/books?id=eI8p5B1uTJMC&pg=PA496&dq=trichloroacetyl+protecting+group+cleaved&hl=cs&sa=X&ei=sKqOVe3mMojMygO-wI7oBg&ved=0CCIQ6AEwAA#v=onepage&q=trichloroacetyl%20protecting%20group%20cleaved&f=false

and

https://books.google.cz/books?id=KPyGzoxfAt0C&pg=PA773&dq=trichloroacetyl+protecting+group+cleaved&hl=cs&sa=X&ei=sKqOVe3mMojMygO-wI7oBg&ved=0CCoQ6AEwAQ#v=onepage&q=trichloroacetyl%20protecting%20group%20cleaved&f=false

Can you rip it off the nitrogen by refluxing the trichloroacetate in the presence of AgNO3 in MeCN?  Not subtle but it may work.

Thank you very much for the useful answers, I will try everything and let you know about the results.

NaBH4 in EtOH should work quite well as for the trifluoroacetyl

At last I found a method to remove the trichloroacetic group. I dissolved my substance in concentrated HCl and worked up the reaction as soon as possible. If I left the reaction to proceed for more than 20 minutes, some kind of white substance precipitated instead of my product (maybe some kind of ring closure took place) and I could not dissolve that in anything.

I tried NaBH4 in EtOH, I refluxed the reaction for 1 day, but nothing happened. I did the same with 4 M LiOH in MeOH, I even tried AgNO3 in MeCN.

Thank you so much for the answers, I learnt a lot.

Congrats Timea!

Just one thing: after using HCl, your amine becomes an amine-HCl salt. I assume your work-up procedure took accout of that. Examples 1 and 2, for instance, in my previous post explain how that is done.

I suggest vigorous alkaline hydrolysis.