ORGANIC ELECTROLUMINESCENT COMPOUNDS AND ORGANIC ELECTROLUMINESCENT DEVICE COMPRISING THE SAME

Abstract

The present disclosure relates to organic electroluminescent compounds and an organic electroluminescent device comprising the same. The organic electroluminescent compound according to the present disclosure may be comprised in a light-emitting layer or an electron buffer layer, and is effective to produce an organic electroluminescent device having low driving voltage, excellent current and power efficiencies, and significantly improved operative lifespan.

Claims

1. An organic electroluminescent compound represented by the following formula 1: ##STR00093## wherein X.sub.1 represents —N═, —NR.sub.7—, —O—, or —S—; Y.sub.1 represents —N═, —NR.sub.8—, —O—, or —S—; with the provisos that when X.sub.1 represents —N═, then Y.sub.1 represents —NR.sub.8—, —O—, or —S—, and when X.sub.1 represents —NR.sub.7—, then Y.sub.1 represents —N═, —O—, or —S—, with the provisos that X.sub.1 and Y.sub.1 are not simultaneously —O—; X.sub.1 and Y.sub.1 are not simultaneously —S—; X.sub.1 and Y.sub.1 are not —O—and —S—, respectively; and X.sub.1 and Y.sub.1 are not —S— and —O—, respectively; R.sub.1 represents a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl; R.sub.2 represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, a substituted or unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, a substituted or unsubstituted tri(C6-C30)arylsilyl, a substituted or unsubstituted mono- or di- (C1-C30)alkylamino, a substituted or unsubstituted mono- or di- (C6-C30)arylamino, or a substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino; R.sub.3, R.sub.4, R.sub.7, and R.sub.8, each independently, represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, a substituted or unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, a substituted or unsubstituted tri(C6-C30)arylsilyl, a substituted or unsubstituted mono- or di-(C1-C30)alkylamino, a substituted or unsubstituted mono- or di- (C6-C30)arylamino, or a substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino; or are linked to an adjacent substituent(s) to form a substituted or unsubstituted, mono- or polycyclic, (C3-C30) alicyclic or aromatic ring, whose carbon atom(s) may be replaced with at least one heteroatom selected from nitrogen, oxygen, and sulfur; a represents 1; b and c, each independently, represent 1 or 2; d represents an integer of 1 to 4; and the heteroaryl contains at least one heteroatom selected from B, N, O, S, Si, and P.

2. The organic electroluminescent compound according to claim 1, wherein formula 1 is represented by the following formula 2: ##STR00094## wherein L.sub.1 represents a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene; X.sub.2 to X.sub.4, each independently, represent —N— or —CR.sub.9—; Ar.sub.1 and Ar.sub.2, each independently, represent a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl; R.sub.9 has the same definition as R.sub.2 to R.sub.4; e represents an integer of 1 to 3; and X.sub.1, Y.sub.1, R.sub.1 to R.sub.4, a, b, and c are as defined in claim 1.

3. The organic electroluminescent compound according to claim 1, wherein formula 1 is represented by the following formula 3: ##STR00095## wherein L.sub.1 represents a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene; Z represents a single bond, or a substituted or unsubstituted (C1-C6)alkylene; R.sub.5 and R.sub.6, each independently, have the same definition as R.sub.2 to R.sub.4; n represents 0 or 1; e represents an integer of 1 to 3; f and g, each independently, represent an integer of 1 to 4; and X.sub.1, Y.sub.1, R.sub.1 to R.sub.4, a, b and c are as defined in claim 1.

4. The organic electroluminescent compound according to claim 1, wherein formula 1 is represented by the following formula 4: ##STR00096## wherein L.sub.1 represents a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene; Z represents a single bond, or a substituted or unsubstituted (C1-C6)alkylene; W represents —NR.sub.10—, —O—, —S—, or —CR.sub.11R.sub.12—; R.sub.10 represents a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl; R.sub.11 and R.sub.12, each independently, represent a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl; R.sub.5 and R.sub.6, each independently, have the same definition as R.sub.2 to R.sub.4; n represents 0 or 1; e and h, each independently, represent an integer of 1 to 3; g represents an integer of 1 to 4; and X.sub.1, Y.sub.1, R.sub.1 to R.sub.4, a, b and c are as defined in claim 1.

5. The organic electroluminescent compound according to claim 1, wherein the compound represented by formula 1 is selected from the group consisting of: ##STR00097## ##STR00098## ##STR00099## ##STR00100## ##STR00101## ##STR00102## ##STR00103## ##STR00104## ##STR00105## ##STR00106## ##STR00107## ##STR00108## ##STR00109## ##STR00110## ##STR00111## ##STR00112## ##STR00113## ##STR00114## ##STR00115## ##STR00116## ##STR00117## ##STR00118## ##STR00119## ##STR00120## ##STR00121## ##STR00122## ##STR00123## ##STR00124## ##STR00125## ##STR00126## ##STR00127## ##STR00128## ##STR00129## ##STR00130## ##STR00131##

6. An organic electroluminescent device comprising the organic electroluminescent compound according to claim 1 as a host material.

Description

Example 1: Preparation of Compound C-24

[0067] ##STR00079##

[0068] 1) Preparation of Compound 1-1

[0069] After introducing compound A (CAS: 1044146-16-8, 36 g, 124 mmol), 4-chloro-2-formylbenzene boronic acid (25.2 g, 136 mmol), tetrakis(triphenylphosphine)palladium (5.7 g, 5.0 mmol), sodium carbonate (33 g, 150 mmol), toluene (600 mL), ethanol (150 mL), and distilled water (150 mL) into a reaction vessel, the mixture was stirred for 3 hours at 140° C. After completing the reaction, the precipitated solid was washed with distilled water and methanol. The obtained compound 1-1 was used in the next reaction without any further purification.

[0070] 2) Preparation of Compound 1-2

[0071] After introducing compound 1-1 (45.6 g, 130 mmol), (methoxymethyl)triphenylphosphonium chloride (74.3 g, 217 mmol), and tetrahydrofuran (1500 mL) into a reaction vessel, the mixture was stirred for 5 minutes. Potassium tert-butoxide (1M in THF, 220 mL) was then slowly added dropwise to the mixture at 0° C. The temperature of the mixture was slowly raised, and the mixture was stirred at room temperature for 3 hours. After completing the reaction by adding distilled water to the reaction solution, an organic layer was extracted with ethyl acetate. The extracted organic layer was dried with magnesium sulfate, and the solvent was removed therefrom using a rotary evaporator. Thereafter, the remaining product was purified by column chromatography to obtain compound 1-2 (48 g, 97%).

[0072] 3) Preparation of Compound 1-3

[0073] After introducing compound 1-2 (44.8 g, 119 mmol), Eaton's reagent (4.5 mL), and chlorobenzene (600 mL) into a reaction vessel, the mixture was refluxed for 2 hours. After completing the reaction, the mixure was cooled to room temperature, and an organic layer was extracted with methylene chloride (MC). After drying the extracted organic layer with magnesium sulfate, the solvent was removed by using a rotary evaporator. Thereafter, the obtained product was purified by column chromatography to obtain compound 1-3 (36.3 g, 89%).

[0074] 4) Preparation of Compound C-24

[0075] After introducing compound 1-3 (8 g, 23 mmol), compound B (CAS: 1060735-14-9, 9.5 g, 23 mmol), tris(dibenzylidyneacetone)dipalladium (1 g, 1.16 mmol), 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (s-phos) (0.95 g, 2.31 mmol), sodium tert-butoxide (4.5 g, 46.3 mmol), and o-xylene (150 mL) into a reaction vessel, the mixture was stirred for 3 hours at 170° C. After completing the reaction, the mixture was added dropwise to methanol, and the obtained solid was filtered. The obtained solid was purified by column chromatography to obtain compound C-24 (8.7 g, 68%).

Example 2: Preparation of Compound C-1

[0076] ##STR00080##

[0077] 1) Preparation of Compound 2-1

[0078] After introducing compound C (10 g, 29 mmol), bis(pinacolato)diborane (8.8 g, 34.8 mmol), tris(dibenzylidyneacetone)dipalladium (1.3 g, 1.45 mmol), 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (s-phos) (1.2 g, 2.9 mmol), potassium acetate (8.5 g, 87 mmol), and 1,4-dioxane (150 mL) into a reaction vessel, the mixture was stirred for 3 hours at 140° C. After completing the reaction, the mixure was cooled to room temperature, and an organic layer was extracted with ethyl acetate. After drying the extracted organic layer with magnesium sulfate, the solvent was removed by using a rotary evaporator. Thereafter, the obtained product was purified by column chromatography to obtain compound 2-1 (10.4 g, 82%).

[0079] 2) Preparation of Compound C-1

[0080] After introducing compound 2-1 (10 g, 23.8 mmol), 2-chloro-4,6-diphenyltriazine (CAS: 3842-55-5, 6.4 g, 23.8 mmol), tris(dibenzylidyneacetone)dipalladium (1 g, 1.16 mmol), 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (s-phos) (1 g, 2.31 mmol), sodium tert-butoxide (4.5 g, 46.3 mmol), and o-xylene (150 mL) into a reaction vessel, the mixture was stirred for 3 hours at 170° C. After completing the reaction, the mixture was added dropwise to methanol, and the obtained solid was filtered. The obtained solid was purified by column chromatography to obtain compound C-1 (8.2 g, 55%).

Example 3: Preparation of Compound C-17

[0081] ##STR00081##

[0082] After introducing compound C (8 g, 23.1 mmol), compound D (CAS: 1448296-00-1, 7.7 g, 23.1 mmol), tetrakis(triphenylphosphine)palladium (1.4 g, 1.19 mmol), potassium carbonate (8.2 g, 60 mmol), toluene (90 mL), ethanol (30 mL), and distilled water (30 mL) into a reaction vessel, the mixture was stirred for 3 hours at 140° C. After completing the reaction, the precipitated solid was washed with distilled water and methanol. The obtained compound was purified by column chromatography to obtain compound C-17 (8.7 g, 77%).

Example 4: Preparation of Compound C-39

[0083] ##STR00082##

[0084] 1) Preparation of Compound 3-1

[0085] After introducing compound E (CAS: 913835-76-4, 40 g, 212.7 mmol), benzaldehyde (27 g, 255.29 mmol), sodium cyanide (10.4 g, 212.7 mmol), and N,N-dimethylformamide (DMF) (1000 mL) into a reaction vessel, the mixture was stirred for 3 hours at 100° C. The reaction solution cooled to room temperature was extracted with ethyl acetate. The obtained compound 3-1 was used in the next reaction without any further purification.

[0086] 2) Preparation of Compound 3-2

[0087] After introducing compound 3-1 (35 g, 128 mmol), 4-chloro-2-formylbenzene boronic acid (26 g, 141 mmol), tetrakis(triphenylphosphine)palladium (6 g, 5.1 mmol), sodium carbonate (34 g, 320 mmol), toluene (600 mL), ethanol (150 mL), and distilled water (150 mL) into a reaction vessel, the mixture was stirred for 3 hours at 140° C. After completing the reaction, the precipitated solid was washed with distilled water and methanol. The obtained compound 3-2 was used in the next reaction without further purification.

[0088] 3) Preparation of Compound 3-3

[0089] After introducing compound 3-2 (19 g, 56.9 mmol), (methoxymethyl)triphenylphosphonium chloride (29.3 g, 85.4 mmol), and tetrahydrofuran (500 mL) into a reaction vessel, the mixture was stirred for 5 minutes. Potassium tert-butoxide (1M in THF, 85 mL) was then slowly added dropwise to the mixture at 0° C. The temperature of the mixture was slowly raised, and the mixture was stirred at room temperature for 3 hours. After completing the reaction by adding distilled water to the reaction solution, an organic layer was extracted with ethyl acetate. The obtained organic layer was dried with magnesium sulfate, and the solvent was removed therefrom using a rotary evaporator. Thereafter, the remaining product was purified by column chromatography to obtain compound 3-3 (16.4 g, 80%).

[0090] 4) Preparation of Compound 3-4

[0091] After introducing compound 3-3 (14.4 g, 39.8 mmol), Eaton's reagent (1.4 mL), and chlorobenzene (200 mL) into a reaction vessel, the mixture was refluxed for 2 hours. After completing the reaction, the mixure was cooled to room temperature, and an organic layer was extracted with methylene chloride (MC). After drying the extracted organic layer with magnesium sulfate, the solvent was removed by using a rotary evaporator. Thereafter, the obtained product was purified by column chromatography to obtain compound 3-4 (11.1 g, 79%).

[0092] 5) Preparation of Compound C-39

[0093] After introducing compound 3-4 (4 g, 12.1 mmol), compound B (CAS: 1060735-14-9, 4.9 g, 12.1 mmol), tris(dibenzylidyneacetone)dipalladium (0.5 g, 0.61 mmol), 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (s-phos) (0.5 g, 1.21 mmol), sodium tert-butoxide (2.33 g, 24.3 mmol), and o-xylene (100 mL) into a reaction vessel, the mixture was stirred for 3 hours at 170° C. After completing the reaction, the mixture was added dropwise to methanol, and the obtained solid was filtered. The obtained solid was purified by column chromatography to obtain compound C-39 (8.7 g, 47%).

Example 5: Preparation of Compound C-49

[0094] ##STR00083##

[0095] 1) Preparation of Compound 2-1

[0096] Compound 2-1 was prepared in the same manner as described in Example 2.

[0097] 2) Preparation of Compound C-49

[0098] After introducing compound 2-1 (4.5 g, 10 mmol), 2-chloro-4,6-diphenylpyrimidine (CAS: 2915-16-4, 2.7 g, 10 mmol), tetrakis(triphenylphosphine)palladium (0.47 g, 0.4 mmol), potassium carbonate (3.6 g, 26 mmol), toluene (50 mL), ethanol (13 mL), and distilled water (13 mL) into a reaction vessel, the mixture was stirred for 4 hours at 120° C. After completing the reaction, the mixture was added dropwise to methanol, and the obtained solid was filtered. The obtained solid was purified by column chromatography to obtain compound C-49 (4.5 g, 73%).

Example 6: Preparation of Compound C-75

[0099] ##STR00084##

[0100] 1) Preparation of Compound 4-1

[0101] After introducing compound F (7.2 g, 21.8 mmol), bis(pinacolato)diborane (6.6 g, 26.2 mmol), tris(dibenzylidyneacetone)dipalladium (1.0 g, 1.1 mmol), 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (s-phos) (0.89 g, 2.2 mmol), potassium acetate (6.4 g, 65 mmol), and 1,4-dioxane (150 mL) into a reaction vessel, the mixture was stirred for 3 hours at 140° C. After completing the reaction, the mixure was cooled to room temperature, and an organic layer was extracted with ethyl acetate. After drying the extracted organic layer with magnesium sulfate, the solvent was removed by using a rotary evaporator. Thereafter, the obtained product was purified by column chromatography to obtain compound 4-1 (5.2 g, 57%).

[0102] 2) Preparation of Compound C-75

[0103] After introducing compound 4-1 (5.2 g, 12.3 mmol), 2-chloro-4,6-diphenylpyrimidine (CAS: 2915-16-4, 3.3 g, 12.3 mmol), tetrakis(triphenylphosphine)palladium (0.71 g, 0.62 mmol), potassium carbonate (4.2 g, 30 mmol), toluene (60 mL), ethanol (20 mL), and distilled water (20 mL) into a reaction vessel, the mixture was stirred for 4 hours at 120° C. After completing the reaction, the mixture was added dropwise to methanol, and the obtained solid was filtered. The obtained solid was purified by column chromatography and recrystallization to obtain compound C-75 (5.3 g, 82%).

Example 7: Preparation of Compound C-87

[0104] ##STR00085##

[0105] 1) Preparation of Compound G

[0106] Compound G was prepared in the same manner as the preparation of compound 3-2 described in Example 4, except for using 5-chloro-2-formylboronic acid instead of 4-chloro-2-formylbenzene boronic acid.

[0107] 2) Preparation of Compound 5-1

[0108] After introducing compound G (15 g, 45.5 mmol), bis(pinacolato)diborane (13.9 g, 54.6 mmol), tris(dibenzylidyneacetone)dipalladium (1.6 g, 1.8 mmol), 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (s-phos) (0.9 g, 3.64 mmol), potassium acetate (13 g, 136 mmol), and 1,4-dioxane (350 mL) into a reaction vessel, the mixture was stirred for 3 hours at 140° C. After completing the reaction, the mixure was cooled to room temperature, and an organic layer was extracted with ethyl acetate. After drying the extracted organic layer with magnesium sulfate, the solvent was removed by using a rotary evaporator. Thereafter, the obtained product was purified by column chromatography to obtain compound 5-1 (20 g, 99%).

[0109] 3) Preparation of Compound C-87

[0110] After introducing compound 5-1 (10 g, 22.7 mmol), 2-chloro-4,6-diphenylpyrimidine (CAS: 2915-16-4, 5.5 g, 20.6 mmol), tetrakis(triphenylphosphine)palladium (1.2 g, 1.0 mmol), potassium carbonate (7.1 g, 56 mmol), toluene (90 mL), ethanol (30 mL), and distilled water (30 mL) into a reaction vessel, the mixture was stirred for 4 hours at 120° C. After completing the reaction, the mixture was added dropwise to methanol, and the obtained solid was filtered. The obtained solid was purified by column chromatography and recrystallization to obtain compound C-87 (5.5 g, 51%).

Example 8: Preparation of Compound C-88

[0111] ##STR00086##

[0112] After introducing compound 5-1 (10 g, 23.7 mmol), 2-chloro-4,6-diphenyltriazine (CAS: 3842-55-5, 5.8 g, 21.6 mmol), tetrakis(triphenylphosphine)palladium (1.2 g, 1.0 mmol), potassium carbonate (7.5 g, 59 mmol), toluene (90 mL), ethanol (30 mL), and distilled water (30 mL) into a reaction vessel, the mixture was stirred for 4 hours at 120° C. After completing the reaction, the mixture was added dropwise to methanol, and the obtained solid was filtered. The obtained solid was purified by column chromatography and recrystallization to obtain compound C-88 (5.7 g, 50%).

Example 9: Preparation of Compound C-45

[0113] ##STR00087##

[0114] 1) Preparation of Compound 9-1

[0115] After introducing compound 7-bromo-2-phenyl-benzoxazole (37 g, 135 mmol), 4-chloro-2-formylbenzene boronic acid (25 g, 135 mmol), tetrakis(triphenylphosphine)palladium (7.8 g, 6.7 mmol), sodium carbonate (35 g, 338 mmol), toluene (680 mL), ethanol (170 mL), and distilled water (170 mL) into a reaction vessel, the mixture was stirred for 3 hours at 130° C. After completing the reaction, the precipitated solid was washed with distilled water and methanol. The obtained compound was purified by column chromatography to obtain compound 9-1 (26 g, 60%).

[0116] 2) Preparation of Compound 9-2

[0117] After introducing compound 9-1 (26 g, 80.2 mmol), (methoxymethyl)triphenylphosphonium chloride (41 g, 120 mmol), and tetrahydrofuran (800 mL) into a reaction vessel, the mixture was stirred for 5 minutes. Potassium tert-butoxide (1 M in THF, 120 mL) was then slowly added dropwise to the mixture at 0° C. The temperature of the mixture was slowly raised, and the mixture was stirred at room temperature for 3 hours. After completing the reaction by adding distilled water to the reaction solution, an organic layer was extracted with ethyl acetate. The extracted organic layer was dried with magnesium sulfate, and the solvent was removed therefrom using a rotary evaporator. Thereafter, the remaining product was purified by column chromatography to obtain compound 9-2 (25 g, 87%).

[0118] 3) Preparation of Compound 9-3

[0119] After introducing compound 9-2 (25 g, 70.2 mmol), Eaton's reagent (3 mL), and chlorobenzene (350 mL) into a reaction vessel, the mixture was refluxed for 2 hours. After completing the reaction, the mixure was cooled to room temperature, and an organic layer was extracted with methylene chloride (MC). After drying the extracted organic layer with magnesium sulfate, the solvent was removed by using a rotary evaporator. Thereafter, the obtained product was purified by column chromatography to obtain compound 9-3 (13 g, 56%).

[0120] 4) Preparation of Compound 9-4

[0121] After introducing compound 9-3 (13 g, 39 mmol), bis(pinacolato)dibororane (12 g, 47 mmol), tris(dibenzylidyneacetone)dipalladium (1.8 g, 1.9 mmol), 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (s-phos) (1.6 g, 3.9 mmol), potassium acetate (11 g, 118 mmol), and 1,4-dioxane (330 mL) into a reaction vessel, the mixture was stirred for 4 hours at 130° C. After completing the reaction, the mixure was cooled to room temperature, and an organic layer was extracted with ethyl acetate. After drying the extracted organic layer with magnesium sulfate, the solvent was removed by using a rotary evaporator. Thereafter, the obtained product was purified by column chromatography to obtain compound 9-4 (13 g, 81%).

[0122] 5) Preparation of Compound C-45

[0123] After introducing compound 9-4 (13 g, 31 mmol), 2-chloro-4,6-diphenyltriazine (8 g, 30 mmol), tetrakis(triphenylphosphine)palladium (1.7 g, 1.5 mmol), potassium carbonate (10 g, 75 mmol), toluene (140 mL), ethanol (35 mL), and distilled water (35 mL) into a reaction vessel, the mixture was stirred for 4 hours at 130° C. After completing the reaction, the precipitated solid was washed with distilled water and methanol. Thereafter, the obtained product was purified by column chromatography to obtain compound C-45 (7.7 g, 49%).

Example 10: Preparation of Compound C-100

[0124] ##STR00088##

[0125] After introducing compound 9-4 (3 g, 7.1 mmol), 2-(3-bromophenyl)-4,6-diphenyl-1,3,5-triazine (CAS: 864377-31-1, 3.04 g, 7.8 mmol), tetrakis(triphenylphosphine)palladium (0.41 g, 0.36 mmol), sodium carbonate (1.9 g, 17.8 mmol), toluene (24 mL), ethanol (6 mL), and distilled water (6 mL) into a reaction vessel, the mixture was stirred for 4 hours at 120° C. After completing the reaction, the mixture was added dropwise to methanol, and the obtained solid was filtered. The obtained solid was purified by column chromatography and recrystallization to obtain compound C-100 (2.3 g, 54%).

Example 11: Preparation of Compound C-101

[0126] ##STR00089##

[0127] After introducing compound 9-4 (3.48 g, 8.3 mmol), 2-([1,1′-biphenyl]-4-yl)-4-chloro-6-phenyl-1,3,5-triazine (CAS: 1472062-94-4, 3.53 g, 9.1 mmol), tetrakis(triphenylphosphine)palladium (0.48 g, 0.41 mmol), sodium carbonate (2.2 g, 20.7 mmol), toluene (28 mL), ethanol (7 mL), and distilled water (7 mL) into a reaction vessel, the mixture was stirred for 5 hours at 120° C. After completing the reaction, the mixture was added dropwise to methanol, and the obtained solid was filtered. The obtained solid was purified by column chromatography and recrystallization to obtain compound C-101 (3.7 g, 74%).

[0128] The properties of the above synthesized compounds are shown in Table 1 below.

TABLE-US-00001 TABLE 1 MS/EIMS Yield UV Spectrum PL Spectrum MP Measured Calculated Compound (%) (in toluene, nm) (in toluene, nm) (° C.) Value Value C-24  68 306 418 240 718.1 717.22 C-1  55 306 426 276 543.2 542.16 C-17  77 306 426 276 642.0 641.19 C-39  47 304 400 230 702.1 701.25 C-49  73 362 420 279 542.0 541.66 C-75  82 260 392 300 526.1 525.18 C-87  51 296 402 278 526.1 525.18 C-88  50 290 427 291 527.1 526.18 C-45  49 345 426 309 526.6 526.18 C-100 54 358 401 298 602.7 602.21 C-101 74 324 429 299 602.7 602.21

[0129] Hereinafter, the luminescent properties of the organic electroluminescent device comprising the organic electroluminescent compound of the present disclosure will be explained in detail with reference to the following examples.

Device Example 1: Preparation of an OLED Device Comprising the Organic Electroluminescent Compounds of the Present Disclosure as a Host

[0130] An OLED device was produced by using the organic electroluminescent compound according to the present disclosure. A transparent electrode indium tin oxide (ITO) thin film (10 Ω/sq) on a glass substrate for an organic light-emitting diode (OLED) device (Geomatec) was subjected to an ultrasonic washing with acetone, ethanol, and distilled water, sequentially, and then was stored in isopropanol. The ITO substrate was then mounted on a substrate holder of a vacuum vapor depositing apparatus. Compound HI-1 was introduced into a cell of said vacuum vapor depositing apparatus, and then the pressure in the chamber of said apparatus was controlled to 10.sup.−6 torr. Thereafter, an electric current was applied to the cell to evaporate the above-introduced material, thereby forming a first hole injection layer having a thickness of 80 nm on the ITO substrate. Next, compound HI-2 was introduced into another cell of said vacuum vapor depositing apparatus, and was evaporated by applying an electric current to the cell, thereby forming a second hole injection layer having a thickness of 5 nm on the first hole injection layer. Compound HT-1 was then introduced into the cell of said vacuum vapor depositing apparatus, and was evaporated by applying an electric current to the cell, thereby forming a first hole transport layer having a thickness of 10 nm on the second hole injection layer. Compound HT-3 was then introduced into another cell of said vacuum vapor depositing apparatus, and was evaporated by applying an electric current to the cell, thereby forming a second hole transport layer having a thickness of 60 nm on the first hole transport layer. After forming the hole injection layer and the hole transport layer, a light-emitting layer was formed thereon as follows: compound C-24 was introduced into one cell of said vacuum vapor depositing apparatus as a host, and compound D-71 was introduced into another cell as a dopant. The dopant was deposited in a doping amount of 3 wt % based on the total amount of the host and dopant to form a light-emitting layer having a thickness of 40 nm on the second hole transport layer. Compound ET-1 and compound EI-1 were then introduced into another two cells, and evaporated at a rate of 1:1 to form an electron transport layer having a thickness of 30 nm on the light-emitting layer. After depositing compound EI-1 as an electron injection layer having a thickness of 2 nm on the electron transport layer, an Al cathode having a thickness of 80 nm was deposited by another vacuum vapor deposition apparatus. Thus, an OLED device was produced.

##STR00090## ##STR00091##

[0131] The produced OLED device showed a red emission having a luminance of 1,000 cd/m.sup.2, and a luminous efficiency of 24.4 cd/A at 4.4 V. The time taken to be reduced to 90% of the luminance, where the early luminance is 100%, at 5,000 nits and a constant current was 43 hours or more.

Device Example 2: Preparation of an OLED Device Comprising the Organic Electroluminescent Compounds of the Present Disclosure as a Host

[0132] An OLED device was produced in the same manner as in Device Example 1, except for using compound C-1 as a host of the light-emitting material. The produced OLED device showed a red emission having a luminance of 1,000 cd/m.sup.2, and a luminous efficiency of 27.8 cd/A at 6.0 V. The time taken to be reduced to 90% of the luminance, where the early luminance is 100%, at 5,000 nits and a constant current was 37 hours or more.

Device Example 3: Preparation of an OLED Device Comprising the Organic Electroluminescent Compounds of the Present Disclosure as a Host

[0133] An OLED device was produced in the same manner as in Device Example 1, except for using the compound C-39 as a host of the light-emitting material. The produced OLED device showed a red emission having a luminance of 1,000 cd/m.sup.2, and a luminous efficiency of 22.9 cd/A at 4.5 V. The time taken to be reduced to 90% of the luminance, where the early luminance is 100%, at 5,000 nits and a constant current was 38 hours or more.

Comparative Device Example 1: Preparation of an OLED Device Comprising Conventional Organic Electroluminescent Compounds

[0134] An OLED device was produced in the same manner as in Device Example 1, except for using the following compound K as a host of the light-emitting material.

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[0135] The produced OLED device showed a red emission having a luminance of 1,000 cd/m.sup.2, and a luminous efficiency of 14.3 cd/A at 10.0 V. The time taken to be reduced to 90% of the luminance, where the early luminance is 100%, at 5,000 nits and a constant current was less than 1 hour.