Chemical Properties
white to pale yellow or beige powder
Uses
Bis(4-nitrophenyl) Carbonate is used a peptide coupling reagent and reagent for formation of carbamate linked cytosines.
Uses
Bis(4-nitrophenyl) carbonate is used as a reagent for preparation of symmetrical and unsymmetrical urea and 4-nitrophenyl esters of N-protected amino acids. It acts as a peptide coupling reagent. It finds application as a reagent for the preparation of carbamate linked cytosines.
reaction suitability
reaction type: Carbonylations
Synthesis
Example 1: Nitration of diphenyl carbonate in the presence of nitrobenzene. To a 2000 mL reactor equipped with a mechanical stirrer, thermometer and jacketed charging funnel was added 107.11 g of diphenyl carbonate (0.5 mol) and 500 mL of nitrobenzene. The mixture was stirred until completely dissolved. Meanwhile, a mixed acid reagent was prepared by mixing 99.02 g of concentrated nitric acid and 125 mL of concentrated sulfuric acid in a beaker under cooling conditions. The cooled mixed acid reagent was transferred to a jacketed charging funnel and further cooled in an ice bath. After diphenyl carbonate was completely dissolved, the temperature of the reaction mixture was adjusted to 20 °C using an ice/water bath. The mixed acid reagent was slowly added dropwise at a rate that maintained the reaction temperature near 20°C for a total dropwise time of about 60 minutes. After the dropwise addition was completed, stirring of the reaction mixture was continued for 60 minutes. Subsequently, the reaction mixture was quenched by pouring the reaction mixture into 600 mL of ice/water mixture. 600 mL of ethyl acetate was added and the mixture was transferred to a dispensing funnel and shaken well. The organic layer was separated and the aqueous layer was extracted three times with 100 mL of ethyl acetate. The organic layers were combined and washed sequentially with 200 mL saturated sodium bicarbonate solution and 200 mL saturated brine. The organic layers were dried over anhydrous sodium sulfate and the ethyl acetate was removed by rotary evaporator. The nitrobenzene solution of the crude product was slowly poured into 2000 mL of cyclohexane and the precipitated crude product (215.16 g) was collected by filtration. Gas chromatographic analysis showed the following product composition: 95.6% 4,4'-dinitrodiphenyl carbonate, 0.6% 4,3'-dinitrodiphenyl carbonate, and 3.8% 4,2'-dinitrodiphenyl carbonate. The crude product was recrystallized by mixed solvent recrystallization from toluene and cyclohexane to give 142.7 g of bis(4-nitrophenyl) carbonate in 94% yield.
Purification Methods
Dissolve the carbonate in CHCl3, wash it with 2N NaOH (3 x) and once with conc HCl, dry (Na2SO4), evaporate and crystallise the residue from toluene (authors say prisms from 15 volumes of *benzene). [Glatthard & Matter Helv Chim Acta 46 795 1963, Beilstein 6 III 820.]
References
[1] Patent: US5037994, 1991, A
[2] Recueil des Travaux Chimiques des Pays-Bas, 1917, vol. 36, p. 51,57, 62
[3] Patent: US4101569, 1978, A
