| 97% |
at 140℃; for 5h; Inert atmosphere; |
|
| 97% |
at 110℃; for 2h; Inert atmosphere; |
|
| 94% |
1) 150 deg C, 1 h; 2) 160 deg C, 4 h; |
|
| 94% |
at 140℃; for 0.0833333h; Microwave irradiation; |
|
| 93% |
at 80℃; for 17h; |
|
|
Heating; |
|
|
In xylene at 80 - 110℃; |
1.A
Example 1A: (2-Bromo-benzyl)-phosphonic acid diethyl ester2-Bromobenzyl bromide (1048 g, 4.2 mol) was melted in a water bath of 60 0C and dissolved in xyleen (734 ml). The solution was heated to 80 0C. Next triethyl phosphite (766 ml, 4.46 mol) was added in three equal portions to the reaction mixture in 60 minutes. The mixture was stirred overnight at 1100C. The reaction mixture was co-evaporated twice with 400 ml of xylene. The xylene was removed in vacuo at 6O0C. The product was dried in a vacuum oven at 600C and was used without further purification.1H-NMR: (CDCI3): 1.33 (6H, t, 2x CH3); 3.43 (1H,s,CH2-a); 3.54 (1H,s,CH2-b); 4.12(4H, q, 2x CH2O); 7.17 (1H1 m, ArH); 7.34 (1 H, m, ArH); 7.55 (1 H, m, ArH), 7.62 (1 H, m, ArH)31P-NMR: (CDCI3): 23.81Mass analysis: M+1 = 307 and 309 (Br-isotopes) found |
|
In toluene at 100 - 116℃; for 2.5h; |
5.A; 5.B
Example 5A+B: trans-2-bromo-2'-acetoxy-5'-chlorostilbene2-Bromobenzyl bromide (25 g, 0.100 mol) and toluene (25 ml) were heated to 100 0C. Next triethyl phosphite (19.3 ml, 0.108 mol) was added over 30 minutes, while the temperature was kept below 116°C. The mixture was stirred for 2 hours at 115°C, while the toluene was distilled.. The mixture was cooled to room temperature and diluted with THF (37.5 ml). KOtBu (30.5 grams, 0.250 mol) was dissolved in THF (176 ml) and cooled to -100C The (2-bromo-benzyl)-phosphonic acid diethyl ester- solution was added at 5 0C. Next chlorosalicylaldehyde (17.2 g, 0.110 mol) in THF (62 ml) was added at 5 0C. The mixture was stirred for one hour at -5°C to 00C. When the reaction was complete acetic anhydride (28.3 ml, 0.301 mol) was added and the temperature was allowed to rise to 200C. The reaction was complete in one hour and the mixture was cooled to 5°C. Next 250 ml 1N HCI is added rapidly. The organic layer is washed with 200 ml saturated NaCI solution. The organic layer is evaporated under reduced pressure at 50 0C, yielding the title stilbene in 25.8 grams, (73%).1H-NMR (CDCI3): 2.38 (3H, s, H-11); 6.87 (1H, d, H-9), 7.19 + 7.34(2 x 1 H, 2 x t, H-2 + H-3), 7.26 (1H, d, H-6), 7.46 (1H, d, H-8), 7.60 (2H, dd, H-1 + H-4), 7.68 (1 H, d, H- 5). ; |
|
In toluene at 115 - 116℃; for 4.5h; |
1
Example 1 (E)-2-(2-Bromostyryl)-4-chlorophenyl acetate2-Bromobenzyl bromide (25 g, 0.100 mol) and toluene (25 ml) were heated to 100 0C. Next triethyl phosphite (19.3 ml, 0.108 mol) was added over 30 minutes, while the temperature was kept below 116°C. The mixture was stirred for 4 hours at 115°C, while the toluene was distilled. The mixture was cooled to room temperature and diluted with tetrahydrofuran (THF; 16.5 ml). KOtBu (30.5 grams, 0.250 mol) was dissolved in THF (176 ml) and cooled to -100C The (2-bromobenzyl)-phosphonic acid diethyl ester solution was added at -5 0C. Next chlorosalicylaldehyde (17.2 g, 0.110 mol) in THF (62 ml) was added at -10 0C. The mixture was stirred for one hour at - 5°C to 00C. When the reaction was complete acetic anhydride (24.5 ml, 0.36 mol) was added and the temperature was allowed to rise to 2O0C. The reaction was stirred for another 15 min and then cooled to 5°C. The pH of the reaction mixture was adjusted to 5 by the addition of 200 ml 1 N HCI. The organic layer was separated and washed with 200 ml saturated NaCI solution. The organic layer was evaporated under reduced pressure at 50 0C, yielding (E)-2-(2-bromostyryl)-4-chlorophenyl acetate in 25.8 grams, (73%). |
|
In xylene at 80 - 110℃; |
1.A
Example 1 A: (2-Bromo-benzyl)-phosphonic acid diethyl ester 2-Bromobenzyl bromide (1048 g, 4.2 mol) was melted in a water bath of 60° C. and dissolved in xyleen (734 ml). The solution was heated to 80° C. Next triethyl phosphite (766 ml, 4.46 mol) was added in three equal portions to the reaction mixture in 60 minutes. The mixture was stirred overnight at 110° C. The reaction mixture was co-evaporated twice with 400 ml of xylene. The xylene was removed in vacuo at 60° C. The product was dried in a vacuum oven at 60° C. and was used without further purification. 1H-NMR: (CDCl3): 1.33 (6H, t, 2*CH3); 3.43 (1H,s,CH2-a); 3.54 (1H,s,CH2-b); 4.12 (4H, q, 2*CH2O); 7.17 (1H, m, ArH); 7.34 (1H, m, ArH); 7.55 (1H, m, ArH), 7.62 (1H, m, ArH) 31P-NMR: (CDCl3): 23.81 Mass analysis: M+1=307 and 309 (Br-isotopes) found |
|
In toluene at 100 - 116℃; for 2.5h; |
5.A+B
Example 5 A+B: trans-2-bromo-2'-acetoxy-5'-chlorostilbene 2-Bromobenzyl bromide (25 g, 0.100 mol) and toluene (25 ml) were heated to 100° C. Next triethyl phosphite (19.3 ml, 0.108 mol) was added over 30 minutes, while the temperature was kept below 116° C. The mixture was stirred for 2 hours at 115° C., while the toluene was distilled. The mixture was cooled to room temperature and diluted with THF (37.5 ml). KOtBu (30.5 grams, 0.250 mol) was dissolved in THF (176 ml) and cooled to -10° C. The (2-bromo-benzyl)-phosphonic acid diethyl ester-solution was added at 5° C. Next chlorosalicylaldehyde (17.2 g, 0.110 mol) in THF (62 ml) was added at 5° C. The mixture was stirred for one hour at -5° C. to 0° C. When the reaction was complete acetic anhydride (28.3 ml, 0.301 mol) was added and the temperature was allowed to rise to 20° C. The reaction was complete in one hour and the mixture was cooled to 5° C. Next 250 ml 1N HCl is added rapidly. The organic layer is washed with 200 ml saturated NaCl solution. The organic layer is evaporated under reduced pressure at 50° C., yielding the title stilbene in 25.8 grams, (73%). 1H-NMR (CDCl3): 2.38 (3H, s, H-11); 6.87 (1H, d, H-9), 7.19+7.34(2*1H, 2*t, H-2+H-3), 7.26 (1H, d, H-6), 7.46 (1H, d, H-8), 7.60 (2H, dd, H-1+H-4), 7.68 (1H, d, H-5). |
|
In toluene at 100℃; |
|
|
at 80 - 130℃; |
2.A A: Preparation of (2-Bromo-benzyl)-phosphonic acid diethyl ester
A: Preparation of (2-Bromo-benzyl)-phosphonic acid diethyl ester:[86] [87] 2-Bromobenzyl bromide ( 20 gm ) was heated in a water bath of 80-90oC . Next triethyl phosphite ( 14.62 gm ) was added to the reaction mixture. Charge another 2-Bromobenzyl bromide (4 Lot x 20 gm) and Triethylphosphite (4 Lot x 14.62 gm) simultaneously through separate addition pots at 80-90oC in such a manner that distillation of Ethyl bromide continues. The mixture was stirred 3-4h at 120-130oC . and further vacuum (680-700mmHg) was applied to reaction mixture to remove volatiles for 2h at 120-130oC . The crude oil was cooled at 25-30oC and oily product (2-Bromo-benzyl)-phosphonic acid diethyl ester was unloded and was used without further purification. |
|
at 140℃; for 5h; |
|
Chemistry
Pharmaceutical Intermediates
Inhibitors/Agonists
Material Science
For Research Only
110K+ Compounds
Competitive Price
1-2 Day Shipping
