BOC

Superiority:

Di-tert-butyl dicarbonate

 

Di-tert-butyl dicarbonate (Diboc) is a new type of amino protective agent, which is used to introduce tert-butoxycarbonyl (BOC) protective agent in organic synthesis, and is especially suitable for amino protection of amino acids. Widely used in medicine, protein and peptide synthesis, biochemistry, food, cosmetics and other products synthesis. The finished product is colorless crystal or colorless liquid, melting point 22~23 ℃, boiling point 56~57 ℃/66 Pa, refractive index (ND20)1.409, relative density (d4) 0.950. Dissolved in tetrahydrofuran, n-hexane, benzene and trichloromethane and other organic solvents, slightly soluble in water. His English name is Di-tert-butyl dicarbonate, and his name and entry number are Dicarbonic acid, bis (1, 1-Dimethylethyl) ester, [24424-99-5].

Basic information

Chinese name
Di-tert-butyl dicarbonate

Foreign name
 Di-tert-butyl dicarbonate

Molecular formula
C10H18O5

Molecular weight
218.25

Chinese name: di-tert-butyl dicarbonate

Chinese alias: di-tert-butyl dicarbonate, di-tert-butyl pyrocarbonate [1]

Commonly known as: BOC

English name: Di-tert-butyl dicarbonate

English alias: Di-tert-butyl pyrocarbonate; di(tert-butyl) carbonate;  di-t-Butyl-dicarbonate Dicarbonic acid, bis(1,1-dimethylethyl)ester; (t.-Boc)2O;  DIBOC;  Dibutyldicarbonate;  BOC anhydride;  BOC-20;  Di-t-butyl pyrocarbonate;  Di-tert butyl dicarbonate;  Di-tert-butyl dicarbonate ;  Di-t-Butyl DICARBONATE

CAS number: 24424-99-5

Molecular formula: C10H18O5

Linear molecular formula: [(CH3)3COCO]2O

Molecular weight: 218.25

Purity: ≥99%

MDL number: MFCD00008805

Beilstein number: 1911173

EC number: 246-240-1

1. Properties: white solid with low melting point

2. Density (g/mL,25/4℃) : 0.949

3. Relative vapor density (g/mL, air =1) : not determined

4. Melting point (ºC) : 22-24

5. Boiling point (ºC,0.5torr) : 56-57

6. Boiling point (ºC,5.2kPa) : not determined

7. Refractive index: 1.4075-1.4095

8. Flash point (ºC) : 37

9. Specific rotation (º) : not determined

10. Spontaneous ignition point or ignition temperature (ºC) : not determined

11. Vapor pressure (kpa,20ºC) : not determined

12. Saturated vapor pressure (kPa,60ºC) : not determined

13. Heat of combustion (KJ/mol) : not determined

14. Critical temperature (ºC) : not determined

15. Critical pressure (KPa) : not determined

16. Value of oil-water (octanol/water) distribution coefficient: not determined

17. Upper explosion limit (%,V/V) : not determined

18. Lower explosive limit (%,V/V) : not determined

19. Solubility: Soluble in most organic solvents, such as carbon tetrachloride, tetrahydrofuran, dioxacyclohexane, alcohol, acetone, acetonitrile,N, n-dimethylformamide, insoluble in cold water. Dispose under dry protective gas at 1.2-8℃.

2. Keep the storage container sealed, place in a tight storage container and store in a cool, dry place.

1. Potassium tert-butanol dissolved in anhydrous tetrahydrofuran, at -5 ~ -20℃ through the dry carbon dioxide, the formation of pulp, continue to maintain low temperature, drop the phosgene benzene solution, the preparation of di-tert-butyl tricarbonate. Dissolve it in carbon tetrachloride, add an appropriate amount of 1, 4-diazadicyclic [2,2,2] octane, stir at 25℃ to release carbon dioxide completely, and convert to di-tert-butyl dicarbonate.

2. Pay attention! The use of highly toxic phosgene should be handled carefully in a ventilated kitchen. All glassware with phosgenetic solvent should be cleaned before taking out the fume hood. (1) To make tert-butyl tricarbonate, dry a 1-liter three-neck flask with a mechanical stirrer, a 200ml constant pressure drip pressure funnel, a calcium chloride drying tube and an inner diameter of not less than 6mm near the bottom of the bottle. Pre-calibrate and mark the level of the drop funnel containing 85 ml and 105 ml of liquid. Fill the flask with dry nitrogen, add 44.8 g (0.40 mol) of non-alcoholic potassium tert-butanol and 550 ml of anhydrous tetrahydroyvean, and stir for 5-10 minutes to form a solution. The reaction bottle is immersed in an ice-salt bath at -5 − 20 ° C, and dry carbon dioxide is added under vigorous agitation for about 30 minutes to form a dense slurry. At the same time, 86 ml of anhydrous benzene was added to the drip funnel and the light bubble was blown in until the volume of phosgene in the benzene solution reached 105 ml, which was equivalent to containing 24 grams (0.24 moles) of phosgene. When the addition reaction of carbon dioxide is completed, the phosgene solution is added to the cooled reactant under intense agitation for about 1 hour, the cold bath temperature is maintained at -5~-10℃, the viscosity of the reaction mixture becomes smaller, and it is still a white emulsion. When the phosgene addition reaction is complete, continue to stir for 45 minutes, while passing anhydrous ethyl nitride to blow out most of the excess phosgene. Remove the instrument on the flask, plug the two necks, and concentrate about 650 ml of solvent to 100 ml with a rotary evaporator under reduced pressure. The flask is still cooled with an ice salt bath to maintain a temperature of 5 to 0 ° C. Due to a small amount of residual photogas in the reaction mixture, exhaust gas from the air pump or vacuum pump should be discharged into the fume hood, the material collected in the cold trap is also evacuated in the fume hood, and the residue containing a very fine dispersion of potassium chloride is filtered by a large diameter sand core funnel, and the funnel is pre-cooled by 50 ml of cold pentane before use. When filtering, use a large diameter funnel to cover the filter funnel, and pass nitrogen to isolate the material from humid air, wash the residue in the flask into the filter funnel with J}} ml of cold pentane, and then wash the filter residue with 2*100 ml of cold pentane. The filtrate was combined with the pentane washing liquid, concentrated with a rotary evaporator at 0℃ under reduced pressure, to obtain a white solid, weighing 33.7 grams, the crude product was dissolved in 1250 ml of pentane, cooled to -15℃, and the white crystal was removed. After the mother liquor is concentrated by the rotary evaporator, two batches of crystals can be obtained, and a total of di-tert-butyl tricarbonate pure product 31.2-32.8(59~62%) is white crystal, melting point 62~63℃(decomposition). (2) di-tert-butylphenol dicarbonate in a beek with an electromagnetic stirring rod, add 20.0 grams (0.076 moles) di-tert-butylvinegar tricarbonate dissolved in i} ml of carbon tetrachloride solution and 0.10 grams (0.0009 moles) newly sublimed 1.4 diazacyclic (2 ·2·2) octane, immediately and rapidly release carbon dioxide. Stir at 25 ° C for 45 minutes to release the carbon dioxide completely, then add 35 ml of water solution containing appropriate citric acid enough to make the water layer slightly acidic. The organic layer was separated, dried with anhydrous magnesium sulfate, concentrated in a rotary evaporator at 25℃, and the residual liquid was distilled under reduced pressure to obtain a colorless liquid of di-tert-butylphenol dicarbonate producing 13.3-- 15.1 g (80~91%). Similar results were obtained with triethylamine as catalyst. However, triethylamine is not as effective as 1, 4-diazadicycloctane because triethylamine may react with solvents and is difficult to separate from the product.

3. Carboyl chloride is prepared by direct reaction with tert-butyl carbonate under the catalysis of 1, 4-diazadicyclic [2.2.2] octane.

1. Used as an intermediate for pharmaceutical and organic synthesis, it is an important amino protective agent used in the synthesis of pharmaceutical and agrochemical products. 2. In organic chemical reactions, (Boc)2O is often used as a tert-butoxycarbonylation reagent for amines, phenols, mercaptans, amides, lacamides, carbamates and other substrates. The reaction rate is fast and the yield is relatively high. Tert-butoxycarbonylation (protection of functional groups) Due to the poor stability of acyl halides, (Boc)2O is widely used as a protective group for amino groups [1,2], which can be removed with trifluoroacetic acid. Aliphatic amines, alicyclic amines, aromatic amines and heterocyclic amines can react with (Boc)2O. Under appropriate conditions, polyfunctional compounds such as diamines (formula 1), amino alcohols, amino acids, etc., can also selectively react with (Boc)2O [3]. Under appropriate conditions, phenols, alcohols, enols and mercaptans can also react with (Boc)2O on functional groups such as hydroxyl groups to provide Boc protection. For other nitrogen-containing compounds, such as amides, lacamides, carbamates, etc., (Boc)2O can also be used as a better protective reagent. It can react with amides and carbamates with weak nucleophilic properties under anhydrous conditions. In the presence of triethylamine and N, n-dimethylaminopyridine (DMAP), secondary amides and lactam compounds can also be protected by Boc using CH2Cl2 as the solvent (Equation 2)[4,5]. In addition, carbanion and Schiff base can react with (Boc)2O under appropriate conditions to generate corresponding tert-butoxycarbonyl compounds (Equation 3)[6]. Amino protective group exchange benzyl oxycarbonyl (Cbz), Fmoc, etc., are also often used as amino protective groups. In the presence of slightly excessive (Boc)2O, amino compounds protected by Cbz and Fmoc can undergo protective group exchange and be transformed into Boc protected amino compounds (Equation 4)[7]. Activation of carboxyl group (Boc)2O can be used not only as a protective group, but also as an activating group of carboxyl group (Equation 5). This is mainly because Boc group is a relatively good leaving group. After reacting with carboxyl group, BOC group can leave under appropriate conditions, so that the carboxyl group is in a non-electroneutral state with good electrophilicity [8].

R10:Flammable. R10:Flammable.

R26:Very toxic by inhalation. R26: very toxic by inhalation.

R36/37/38:Irritating to eyes, respiratory system and skin.  Irritates the eyes, respiratory system and skin. ;

R43:May cause sensitization by skin contact.  May sensitize in contact with skin.

S16:Keep away from sources of ignition.  Keep away from fire.

S24:Avoid contact with skin. S24:Avoid contact with skin.

S37/39:Wear suitable gloves and eye/face protection. S37/39:Wear suitable gloves and eye/face protection.

S45:In case of accident or if you feel unwell,  seek medical advice immediately (show the label whenever possible.) Seek medical advice immediately (show the label whenever possible.)

CAS number: 24424-99-5

MDL number: MFCD00008805

EINECS number: 246-240-1

RTECS number: HT0230000

BRN number: 1911173

PubChem number: 24862282

Fold and edit the toxicology data in this paragraph
On the skin: Caustic effect. Irritates the skin and mucous membranes.

On the eyes: Strong corrosive effect. The effect of stimulation.

Sensitization: Sensitization may occur through skin contact.

1, molar refractive index: 53.60

2, molar volume (m3/mol) : 207.0

3. Isotropic specific volume (90.2K) : 489.3

4, surface tension (dyne/cm) : 31.2

5. Polarizability (10-24cm3) : 21.25

1. Reference value of hydrophobic parameter calculation (XlogP) : 2.7

2. Number of hydrogen bond donors: 0

3. Number of hydrogen bond receptors: 5

4. Number of rotatable chemical bonds: 6

5. Topological molecular polar surface area (TPSA) : 61.8

6. Number of heavy atoms: 15

7, surface charge: 0

8. Complexity: 218

9. Number of isotope atoms: 0

10. Determine the number of atomic stereocenter: 0

11. Number of uncertain atomic stereocentes: 0

12. Determine the number of chemical bond structure centers: 0

13. Number of uncertain chemical bond structure centers: 0

14. Number of covalent bond units: 1

It is slightly harmful to the water, if the government permits, do not discharge the material into the surrounding environment.

1. If used and stored according to specifications, it will not decompose

Avoid contact with oxides, moisture/humidity, heat

2. Sensitive to moisture, flammable, need to be stored in the refrigerator, the use temperature should not exceed 80 oC.

Safety information
Packing grade: I
Hazard category: 6.1
Customs Code: 29209010
Dangerous Goods Transport Code: UN 2929 6.1/PG 1
WGK Germany: 3
Danger category code: R11:Highly Flammable. R19:May form explosive peroxides. R26:Very Toxic by inhala

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