Use of compressed CO2 in chemical reactions

Di(1H, 1H, 2H, 2H-perfluorooctyl)phenylphosphine oxide

A solution of 1H, 1H, 2H, 2H-perfluorooctyl iodide (18.96 g, 40 mmol) in ether (80 ml) was added to a suspension of magnesium turnings (1.920 g, 80 mmol), with a trace of iodine, also in ether (40 ml). The mixture was stirred at room temperature overnight, the stirring was stopped and the remaining solids allowed to settle. The resulting Grignard reagent, as a solution in ether, was added via cannula to a solution of dichlorophenylphosphine (1.79 g, 10 mmol) also in ether (80 ml). This addition was accompanied by the rapid formation of a white precipitate. The mixture was stirred at room temperature for a further 3 hrs when aqueous hydrochloric acid (100 ml of a 1M solution) was added. The mixture was extracted with ether (4×250 ml) and the organic fractions combined, dried (MgSO 4 ) and concentrated in vacuo to give the crude product (10.18 g) which was used in the next step without purification.

Sodium periodate (3.0 g, 15 mmol) was added to a solution of the crude phosphine (10.18 g) in acetone (100 ml) and the mixture stirred at room temperature overnight. The solvent was removed in vacua and water (200 ml) added, the resulting mixture was extracted with ether (4×250 ml) and the organic fractions combined, dried (MgSO 4 ) and concentrated in vacuo to give the crude product. The product was purified by flash column chromatography on silica gel, eluting with dichloromethane to give a white crystalline solid (5.94 g, 7.26 mmol, 73%), mp (CH 2 Cl 2 ) 91-93 C. (Found: M + , 819.0313. C 22 H 13 F 26 PO requires M+, 819.0367).

(1H, 1H, 2H, 2H-perfluorooctyl)diphenylphosphine

Trichlorosilane (0.1 ml, 1 mmol) was added, at room temperature, to a suspension of (1H, 1H, 2H, 2H-perfluorooctyl)diphenylphosphine oxide (55 mg, 0.1 mmol) and triethylamine (0.1 ml, 0.7 mmol) in toluene (5 ml). The mixture was then heated at 100 C. overnight and then allowed to cool. Aqueous sodium hydroxide (40 ml of a 1M solution) was added and the resulting mixture extracted with ether (4×25 ml). The organic fractions were combined, dried (MgSO 4 ) and concentrated in vacuo to give the crude product. The product was purified by flash column chromatography on silica gel, eluting with hexane to give a white crystalline solid (42 mg, 0.079 mmol, 79%), mp (CH 2 Cl 2 ) 44-45° C. (Found: M+,532.0600. C 20 H 14 F 13 P requires M+, 532.0625).

Di(1H, 1H, 2H, 2H-perfluorooctyl)phenylphosphine

Trichlorosilane (1 ml, 10 mmol) was added, at room temperature, to a solution of di(1H, 1H, 2H, 2H-perfluorooctyl)phenylphosphine oxide (818 mg, 1 mmol) and triethylamine (1 ml, 7.2 mmol) in toluene (40 ml). The mixture was then heated at 100 C. overnight and then allowed to cool. Aqueous sodium hydroxide (100 ml of a 1M solution) was added and the resulting mixture extracted with ether (3×250 ml). The organic fractions were combined, dried (MgSO 4 ) and concentrated in vacuo to give the crude product. The product was purified by flash column chromatography on silica gel, eluting with hexane to give a white crystalline solid (710 mg, 0.88 mmol, 88%), mp (CHCl 3 ) 37-39° C. (Found: M+, 802.0319. C 22 H 13 F 26 P requires M+, 802.0339).

Bis{(1H H,2H,2H-perfluorooctyl)diphenyliphosphino}-palladium dichloride

A solution of (1H, 1H, 2H, 2H-perfluorooctyl)diphenylphosphine (53 mg, 0.1 mmol) in chloroform (1 ml) was added to bis(acetonitrile)palladium dichoride (13 mg, 0.05 mmol). After 1 hr the solution was concentrated in vacuo to give the product as a orange crystalline solid (53 mg, 0.043 mmol, 86%), mp (CH 2 Cl 2 ) 149-151 C. (Found: M+—Cl, 1205.0061. C 40 H 28 C l2 F 26 P 2 Pd requires M+—Cl, 1204.9974).

Bis{di(1H,1H,2H,2H-perfluorooctyl)phenylphosphino-palladium dichloride

A solution of di(1H,1H,2H,2H-perfluorooctyl)phenylphosphine (401 mg, 0.5 mmol) in dichloromethane (5 ml) was added to bis(acetonitrile)palladium dichoride (65 mg, 0.25 mmol). After 1 hr the solution was concentrated in vacuo to give the product as a orange crystalline solid (435 mg, 0.244 mmol, 97%), mp (CH 2 Cl 2 ) 91-93 C. (Found: M+—Cl, 1744.9402. C 44 H 26 Cl 2 F 52 P 2 Pd requires M+—Cl, 1744.9403).

Diphenylacetylene

Bis{di(1H,1H,2H,2H-perfluorooctyl)phenylphosphino}palladium dichloride (89 mg, 0.05 mmol), copper (I) iodide (9 mg, 0.05 mmol), iodobenzene (0.11 ml, 1 mmol), phenylacetylene (0.11 ml, 1 mmol) and triethylamine (0.15 ml, 1.1 mmol) were placed in a 10 ml stainless steel cell. The cell was sealed and pressurised to approximately 6900 kPa (1000 psi) (full of carbon dioxide). The cell was then heated to 60 C. for 40 hrs and then allowed to cool. When the pressure had dropped below 13800 kPa (2000 psi), the cell was vented into ether (100 ml), the cell was opened once atmospheric pressure was reached and washed out with a further quantity of ether (20 ml). The extracts were combined and washed with water (100 ml). The resultant aqueous layer was further extracted with ether (2×100 ml) and the organic fractions combined, dried (MgSO 4 ) and concentrated in vacuo to give the crude product. The product was purified by flash column chromatography on silica gel, eluting with hexane to give a white crystalline solid (105 mg, 0.60 mmol, 60%); SH (250 MHz; CDCl 3 ) 7.56-7.61 (4H, m, o-Ph), 7.33-7.43 (6H, m, m/pPh); δ C 131.7 (o-C), 128.5 (m-Ph), 128.4 (p-Ph), 123.4 (quaternary Ph), 89.5 (alkyne).

The reaction was also conducted at higher temperatures (80 and 100 C.) by the same procedure, except that the cell was filled approximately three quarters full with carbon dioxide and then brought to the reaction temperature. Once at this temperature, the pressure was increased until approx. 25600 kPa (4000 psi).

3-Methylindole

Di(1H,2H,2H-perfluorooctyl)phenylphosphine (80 mg, 0.1 mmol), palladium (II) acetate (11 mg, 0.05 mmol), N-allyl-2-iodoaniline (259 mg, 1 mmol) and triethylamine (0.15 ml, 1.1 mmol) were placed in a 10 ml stainless steel cell. The cell was sealed and pressurised to approximately 5520 kPa (800 psi) (i.e. full of carbon dioxide). The cell was then heated to 100 C. for 64 hrs and then allowed to cool. When the pressure had dropped below 13800 kPa (2000 psi), the cell was vented into ether (100 ml), the cell was opened once atmospheric pressure was reached and washed out with dichloromethane (20 ml). The organic fractions were combined and concentrated in vacuo to give the crude product. The product was purified by flash column chromatography on silica gel, eluting with 20% ether in hexane to give a white crystalline solid (49 mg, 0.37 mmol, 37%); δ H (250 MHz; CDCl 3 ) 7.85 (1H, br, NH), 7.63 (1H, m, H7), 7.34 (1H, m, H4), 7.15-7.26 (2H, m, H5 and H6), 6.97 (1H, s, NHCH), 2.38 (3H, s, Me).

Biphenyl

Bis{di(1H,1H,2H,2H-perfluorooctyl)phenylphosphino}palladium dichloride (89 mg, 0.05 mmol), iodobenzene (0.11 ml, 1 mmol), phenylboronic acid (122 mg, 1 mmol) and triethylamine (0.15 ml, 1.1 mmol) were placed in a 10 ml stainless steel cell. The cell was sealed and pressurised to approximately 5520 kPa (800 psi) (i.e. full of carbon dioxide). The cell was then heated to 100 C. for 64 hrs and then allowed to cool. When the pressure had dropped below 13800 kPa (2000 psi) the cell was vented into ether (100 ml), the cell was opened once atmospheric pressure was reached and washed out with dichloromethane (20 ml). The organic fractions were combined and concentrated in vacuo to give the crude product. The product was purified by flash column chromatography on silica gel, eluting with hexane to give a white crystalline solid (80 mg, 0.52 mmol, 52%); δ H (250 MHz; CDCl 3 ) 7.34-7.65 (10H, m, aryl).

2-Phenylthiophene

Bis{di(1H,1H,2H,2H-perfluorooctyl)phenylphosphino}palladium dichloride (89 mg, 0.05 mmol), iodobenzene (0.11 ml, 1 mmol), thiophene-2-boronic acid (128 mg, 1 mmol) and triethylamine (0.15 ml, 1.1 mmol) were placed in a 10 ml stainless steel cell. The cell was sealed and pressurised to approximately 5520 kPa (800 psi) (i.e. full of carbon dioxide). The cell was then heated to 100 C. for 64 hrs and then allowed to cool. When the pressure had dropped below 13800 kPa (2000 psi) the cell was vented into ether (100 ml), the cell was opened once atmospheric pressure was reached and washed out with dichloromethane (20 ml). The organic fractions were combined and concentrated in vacuo to give the crude product. The product was purified by flash column chromatography on silica gel, eluting with hexane to give a white crystalline solid (78 mg, 0.49 mmol, 49%); δ H (250 MHz; CDCl 3 ) 7.09-7.66 (8H, m, aryl and thienyl).

EXAMPLES 11 to 17

Heck Reactions

The following reactions and conditions were used: iodide (1.0 mmol), alkene (1.0 mmol), triethylamine (1.1 mmol), catalyst (5 mol %), 40 h, 100° C.

A typical procedure was as follows: bis(1H,1H,2H,2Hperfluorooctyl)phenylphosphine (80 mg, 0.1 mmol), palladium (II) acetate (11 mg, 0.05 mmol), iodobenzene (0.11 ml, 1 mmol), methyl acrylate (0.11 ml, 1 mmol) and triethylamine (0.15 ml, 1.1 mmol) were placed in a 10 ml stainless steel cell. The cell was sealed and pressurised to approximately 6900 kPa (1000 psi) (about ¾ full of liquid carbon dioxide). The suspended reagents were magnetically stirred and afforded a dark red-coloured medium as the cell was heated to 100° C. The reagents were stirred at this temperature for 40 h when a crystalline deposit formed on the sapphire window. The cell was then cooled, and when the pressure had dropped below 13800 kPa (2000 psi), the cell was vented into ether (100 ml), the cell was opened once atmospheric pressure was reached and washed out with a quantity of dichloromethane (10 ml). The organic fractions were combined and concentrated in vacuo to give the crude product. The product was purified by flash column chromatography on silica gel, eluting with dichloromethane to give trans-methylcinnamate as a white crystalline solid (157 mg, 0.97 mmol, 97%); [CAS 1754-62-7] mp 35-37° C.

This and other Heck reactions are tabulated below.

Trans-3-phenylacrylic acid methyl ester (trans-methylcinnamate)

Bis(1H,1H,2H,2H-perfluorooctyl)phenylphosphine (14.5 mg, 0.019 mmol), palladium (II) acetate (2 mg, 0.009 mmol), iodobenzene (0.02 ml, 0.22 mmol), REM Resin (Aldrich, 250 mg, 0.25-1.25 mmol) and triethylamine (0.03 ml, 0.22 mmol) were placed in a 10 ml stainless steel cell. The cell was sealed and pressurised to approximately 6900 kPa (1000 psi) (about ¾ full of liquid carbon dioxide). The suspended reagents were magnetically stirred and afforded a dark red-coloured medium, the resin remained as a powder in the bottom of the cell. The cell was heated to 100° C. and the reaction mixture stirred at this temperature for 40 h. The cell was then cooled, and when the pressure had dropped below 13800 kPa (2000 psi), the cell was vented into ether (100 ml), the cell was opened once atmospheric pressure was reached and washed out with a quantity of dichloromethane (10 ml). The resulting resin was removed from the cell and washed (Soxhlet) with dichloromethane (100 ml) for 24 h. The resin was then dried under vacuum, to a constant weight, (257 mg) and a portion taken for analysis and release of the product by transesterification. The resin (102 mg, <0.05 mmol) was suspended in a solution of sodium methoxide (8 mg, 0.15 mmol) in methanol (2 ml) and THF (8 ml). The mixture was heated at reflux for 24 h, after cooling the resin was removed by filtration and washed with methanol (5 ml) and ether (5 ml). The filtrate was concentrated in vacuao and the product purified by flash chromatography on silica gel, eluting with 10% ether in hexane to give the title compound as a white crystalline solid (6 mg, 0.037 mmol, >74%). [CAS 1754-62-7] mp 35-37° C.

Copolymerisation of 1 and 4

A mixture of monomers 1 and 4 (55:45 wt/wt) was purified by passing though a neutral alumina column. This mixture (2.0 g) and 2,2′-azobisisobutyronitrile (AlBN, 0.16 g) was added to a 10 mL high pressure reactor, equipped with a sapphire window for the observation of phase behaviour. The reactor was purged with a slow flow of CO 2 for 20 min, after which time the vessel was filled with liquid CO 2 (T=22° C., P=64 bar) and stirring was commenced using a PTFE-coated magnetic str bar. Under these initial conditions, much of the monomer mixture was insoluble in the liquid CO 2 phase, and the reaction mixture existed as a white, cloudy suspension. The reactor was heated to achieve the required polymerisation conditions (65° C., P=290±10 bar) and a fine white precipitate began to form in the reactor after around 90 min. The reactorwas left stirring at 65° C. for24 h, after which the system was cooled to ambient temperature. The CO 2 was vented slowly though acetone to trap any polymer/monomer that might otherwise escape during venting. The polymer was *removed from the reactor as a dry, white, free-flowing powder. The reactor was then rinsed with acetone to collect any residual solids. The polymeric product was washed by suspension in a solvent (˜25 mL) followed by centrifuging and decanting. This procedure was repeated twice, both with THF and with methanol. The polymer was then left under acetone overnight, resuspended twice in ethanol, centrifuged, decanted, and dried under vacuum at 50° C. There was no apparent weight loss after the washing procedure, and no soluble polymer fraction was detected. The purified polymer was isolated as a white powder (1.78 g, 89%). Found: C, 90.2; H, 8.3; Calculated: C, 91.6; H, 8.4%. IR (KBr)/cm −1 : 3450, 3018, 2964, 2925, 1603, 1511, 1486, 1449, 903, 834, 795, 710.

Copolymerisation of 1 and 4

A mixture of monomers 1 and 4 (55:45 wt/wt) was purified by passing though a neutral alumina column. This mixture (4.34 g) and AlBN (0.35 g) was added to a 10 mL high pressure reactor, equipped with a sapphire window for the observation of phase behaviour. The reactor was purged with a slow flow of CO 2 for 20 min, after which time the vessel was filled with liquid CO 2 (T=24° C., P=95 bar) and stirring was commenced using a PTFE-coated magnetic stir bar. Under these initial conditions, much of the monomer mixture was insoluble in the liquid CO 2 phase, and the reaction mixture existed as a white, cloudy suspension. The reactor was heated to achieve the required polymerisation conditions (65° C., P=318±10 bar) and a fine white precipitate began to form in the reactor after around 30 min. The reactor was left stirring at 65° C. for 24 h, after which the system was cooled to ambient temperature. The CO 2 was vented slowly though acetone to trap any polymer/monomer that might otherwise escape during venting. The polymer was removed from the reactor as a dry, white, free-flowing powder. The same purification procedures were used as for Example 19. The purified polymer was isolated as a white powder (4.29 g, 99%). Found: C, 88.7; H, 8.0; Calculated: C, 91.6; H, 8.4%. IR (KBr)/cm −1 : 3450, 3018, 2964, 2925, 1603, 1511, 1486, 1449, 903, 834, 795, 710.

Copolymerisation of 1 and 4

A mixture of monomers 1 and 4 (80:20 wt/wt) was purified by passing though a neutral alumina column. This mixture (2.0 g) and AlBN (0.16 g) was added to a 10 mL high pressure reactor, equipped with a sapphire window for the observation of phase behaviour. The reactor was purged with a slow flow of CO 2 for 20 min, after which time the vessel was filled with liquid CO 2 (T=24° C., P=66 bar) and stirring was commenced using a PTFE-coated magnetic stir bar. Under these initial conditions, much of the monomer/polymer mixture was insoluble in the liquid CO 2 phase, and the reaction mixture existed as a white, cloudy suspension, possibly due to early oligomerisation/polymerisation before the vessel was brought up to the reaction temperature. The reactor was heated to achieve the required polymerisation conditions (65° C., P=333±10 bar) and a fine white precipitate began to form in the reactor after a few minutes. The reactor was left stirring at 65° C. for 24 h, after which the system was cooled to ambient temperature. The CO 2 was vented slowly though acetone to trap any polymer/monomer that might otherwise escape during venting. The polymer was removed from the reactor as a dry, white, free-flowing powder. The same purification procedures were used as for Example 19. The purified polymer was isolated as a white powder (1.84 g, 92%). Found: C, 90.1; H, 8.0; Calculated: C, 91.9; H, 8.0%. IR (KBr)/cm −1 : 3450, 3018, 2964, 2925, 1603, 1511, 1486, 1449, 903, 834, 795, 710.

Polymerisation of 2

A mixture of 2 (2.0 g) and AlBN (0.16 g) was added to a 10 mL high pressure reactor, equipped with a sapphire window for the observation of phase behaviour. The reactor was purged with a slow flow of CO 2 for 20 min, after which time the vessel was filled with liquid CO 2 (T=23° C., P=84 bar) and stirring was commenced using a PTFE-coated magnetic stir bar. Under these initial conditions, the monomer was soluble in the liquid CO 2 phase, and the reaction mixture was homogeneous. The reactor was heated to achieve the required polymerisation conditions (65° C., P=295±10 bar), whereupon a yellow colour was observed briefly and a fine white precipitate began to form in the reactor after a few minutes. The reactor was left stirring at 65° C. for 24 h, after which the system was cooled to ambient temperature. The CO 2 was vented slowly though acetone to trap any polymer/monomer that might otherwise escape during venting. The polymer was removed from the reactor as a dry, white, free-flowing powder. The same purification procedures were used as for Example 19. The purified polymer was isolated as a white powder (1.60 g, 80%). IR (KBr)/cm −1 : 2997, 2964, 1737, 1468, 1395, 1356, 1245, 1214, 1150.

Polymerisation of 3

A mixture of 3 (2.0 g) and AlBN (0.16 g) was added to a 10 mL high pressure reactor, equipped with a sapphire window for the observation of phase behaviour. The reactor was purged with a slow flow of CO 2 for 20 min, after which time the vessel was filled with liquid CO 2 (T=27° C., P=82 bar) and stirring was commenced using a PTFE-coated magnetic stir bar. Under these initial conditions, the monomer was soluble in the liquid CO 2 phase, and the reaction mixture was homogeneous. The reactor was heated to achieve the required polymerisation conditions (65° C., P=300±10 bar), whereupon a yellow colour was observed briefly and a fine white precipitate began to form in the reactor after around 30 minutes. The reactor was left stirring at 65° C. for 24 h, after which the system was cooled to ambient temperature. The CO 2 was vented slowly though acetone to trap any polymer/monomer that might otherwise escape during venting. The polymer was removed from the reactor as a dry, white, free-flowing powder. The same purification procedures were used as for Example 19. The purified polymer was isolated as a white powder (1.87 g, 93.5%). Found: C, 62.3; H, 7.6; Calculated: C, 63.9; H, 7.8%. IR (KBr)/cm −1 : 2970, 1735, 1650, 1559, 1542, 1517, 1490, 1461, 1264, 1152.

Copolymerisation of 1, 4 and 5

A mixture of monomers 1 (1.02 g), 4 (0.83 g) and 5 (0.28 g) and AlBN (0.16 g) was added to a 10 mL high pressure reactor, equipped with a sapphire window for the observation of phase behaviour. The reactor was purged with a slow flow of CO 2 for 20 min, after which time the vessel was filled with liquid CO 2 (T=25° C., P=106 bar) and stirring was commenced using a PTFE-coated magnetic stir bar. Under these initial conditions, much of the monomer mixture was insoluble in the liquid CO 2 phase, and the reaction mixture existed as a white, cloudy suspension. The reactor was heated to achieve the required polymerisation conditions (65° C., P=327±10 bar) and a fine white precipitate began to form in the reactor after around 30 min. The reactor was left stirring at 65° C. for 24 h, after which the system was cooled to ambient temperature. The CO 2 was vented slowly though acetone to trap any polymer/monomer that might otherwise escape during venting. The polymer was removed from the reactor as a dry, white, free-flowing powder. The same purification procedures were used as for Example 19. The purified polymer was isolated as a white powder (1.95 g, 92%). Found: C, 87.64; H, 8.02; Cl, 2.70; Calculated: C, 89.55; H, 8.13%; Cl, 2.32. IR (KBr)/cm −1 : 3450, 3018, 2964, 2925, 1603, 1511, 1486, 1449, 903, 834, 795, 710.

Copolymerisation of 1, 4 and 6

A mixture of monomers 1 (0.99 g), 4 (0.81 g) and 6 (0.20 g) and AlBN (0.16 g) was added to a 10 mL high pressure reactor, equipped with a sapphire window for the observation of phase behaviour. The reactor was purged with a slow flow of CO 2 for 20 min, after which time the vessel was filled with liquid CO 2 (T=26° C., P=81 bar) and stirring was commenced using a PTFE-coated magnetic stir bar. Under these initial conditions, much of the monomer mixture was insoluble in the liquid CO 2 phase, and the reaction mixture existed as a white, cloudy suspension. The reactor was heated to achieve the required polymerisation conditions (65° C., P=286±10 bar) and a fine white precipitate began to form in the reactor after a few minutes. The reactor was left stirring at 65° C. for 24 h, after which the system was cooled to ambient temperature. The CO 2 was vented slowly though acetone to trap any polymer/monomer that might otherwise escape during venting. The polymer was removed from the reactor as a dry, white, free-flowing powder. The same purification procedures were used as for Example 19. The purified polymer was isolated as a white powder (1.79 g, 90%). Found: C, 86.3; H, 7.6; Calculated: C, 87.4; H, 7.6%. IR (KBr)/cm −1 : 3450, 3018, 2964, 2925, 1603, 1511, 1486, 1449, 903, 834, 795, 710.

Copolymerisation of 1, 4 and 7

A mixture of monomers 1 (0.99 g), 4 (0.81 g) and 7 (0.20 g) and AISN (0.16 g) was added to a 10 mL high pressure reactor, equipped with a sapphire window for the observation of phase behaviour. The reactor was purged with a slow flow of CO 2 for 20 min, after which time the vessel was filled with liquid CO 2 (T=22° C., P=85 bar) and stirring was commenced using a PTFE-coated magnetic stir bar. Under these initial conditions, much of the monomer mixture was insoluble in the liquid CO 2 phase, and the reaction mixture existed as a white, cloudy suspension. As the reactor was heated, the solution gradually became homogeneous (T>37° C., P>179 bar). A deep red colour was formed under the polymerisation conditions (65° C., P=332±10 bar), followed by the formation of a fine in the reactor after a few minutes. The reactor was left stirring at 65° C. for 24 h, after which the system was cooled to ambient temperature. The CO 2 was vented slowly though acetone to trap any polymer/monomer that might otherwise escape during venting. The polymer was removed from the reactor as a dry, white, free-flowing powder. The same purification procedures were used as for Example 19. The purified polymer was isolated as a white powder (1.79 g, 90%). Found: C, 89.5; H, 8.7; Calculated: C, 90.2; H, 8.8%. IR (KBr)/cm −1 : 2854, 1731, 1603, 1486, 1449, 901, 795, 708.

Copolymerisation of 1, 4 and 8

A mixture of monomers 1 (0.99 g), 4 (0.81 g) and 8 (0.20 g) and AlBN (0.16 g) was added to a 10 mL high pressure reactor, equipped with a sapphire window for the observation of phase behaviour. The reactor was purged with a slow flow of CO 2 for 20 min, after which time the vessel was filled with liquid CO 2 (T=28° C., P=103 bar) and stirring was commenced using a PTFE-coated magnetic stir bar. Under these initial conditions, much of the monomer mixture was insoluble in the liquid CO 2 phase, and the reaction mixture existed as a white, cloudy suspension. The reactor was heated to achieve the required polymerisation conditions (65° C., P=276±10 bar) and a fine white precipitate began to form in the reactor after a few minutes. The reactor was left stirring at 65° C. for 24 h, after which the system was cooled to ambient temperature. The CO 2 was vented slowly though acetone to trap any polymer/monomer that might otherwise escape during venting. The polymer was removed from the reactor as a dry, white, free-flowing powder. The same purificaton procedures were used as for Example 19. The purified polymer was isolated as a white powder (1.80 g, 90%). Found: C, 85.1; H, 7.8; N, 0.9; S, 0.4; Calculated: C, 85.5; H, 7.7; N, 0.2; S, 0.5. IR (KBr)/cm −1 : 3020, 2966, 2927, 1733, 1601, 1484, 1447, 1240, 1213, 1154.

Copolymerisation of 1, 4 and 9

A mixture of monomers 1 (1.28 g), 4 (0.32 g) and 9 (0.40 g) and AlBN (0.16 g) was added to a 10 mL high pressure reactor, equipped with a sapphire window for the observation of phase behaviour. The reactor was purged with a slow flow of CO 2 for 20 min, after which time the vessel was filled with liquid CO 2 (T=29° C., P=86 bar) and stirring was commenced using a PTFE-coated magnetic stir bar. Under these initial conditions, the monomer mixture was soluble in the liquid CO 2 phase, and the reaction mixture existed as a homogeneous solution. The reactor was heated to achieve the required polymerisation conditions (65° C., P=282±10 bar) and a pale yellow colour was observed, followed by the formation of a fine white precipitate in the reactor after a few minutes. The reactor was left stirring at 65° C. for 24 h, after which the system was cooled to ambient temperature. The CO 2 was vented slowly though acetone to trap any polymer/monomer that might otherwise escape during venting. The polymer was removed from the reactor as a dry, white, free-flowing powder. The same purification procedures were used as for Example 19. The purified polymer was isolated as a white powder (1.82 g, 91%). Found: C, 80.4; H, 7.6; Calculated: C, 84.8; H, 7.8%. IR(KBr)/cm −1 : 3047, 3016, 2967, 2931, 1700, 1602, 1449, 1214, 907, 799, 712.

Copolymerisation of 1 and 4 in the presence of surfactant 10

A mixture of monomers 1 and 4 (55:45 wt/wt) was purified by passing though a neutral alumina column. This mixture (2.0 g), AlBN (0.16 g) and surfactant 10 (60 mg) was added to a 10 mL high pressure reactor, equipped with a sapphire window for the observation of phase behaviour. The reactor was purged with a slow flow of CO 2 for 20 min, after which time the vessel was filled with liquid CO 2 (T=22° C., P=75 bar) and stirring was commenced using a PTFE-coated magnetic stir bar. Under these initial conditions, the monomer mixture was emulsified in the liquid CO 2 phase, and the reaction mixture existed as a uniform, white opaque emulsion. The reactor was heated to achieve the required polymerisation conditions (65° C., P=310±10 bar) and polymerisation was carried out. The emulsion persisted during polymerisation and a uniform white appearance was observed throughout. The reactor was left stirring at 65° C. for 24 h, after which the system was cooled to ambient temperature. The CO 2 was vented slowly though acetone to trap any polymer/monomer that might otherwise escape during venting. The polymer was removed from the reactor as a dry, white, free-flowing powder. The reactor was then rinsed with acetone to collect any residual solids. The same purification procedures were used as for Example 19. There was no apparent weight loss after the washing procedure, and no soluble polymer fraction was detected. The purified polymer was isolated as a white powder (1.92 g, 96%). Found: C, 89.9; H, 8.3; Calculated: C, 91.6; H, 8.4%. IR (KBr)/cm −1 : 3450, 3018, 2964, 2925, 1603, 1511, 1486, 1449, 903, 834, 795, 710.

Copolymerisation of 1 and 4 in the Presence of Surfactant 10

A mixture of monomers 1 and 4 (80:20 wt/wt) was purified by passing though a neutral alumina column. This mixture (2.0 g), AlBN (0.16 g) and surfactant 10 (60 mg) was added to a 10 mL high pressure reactor, equipped with a sapphire window for the observation of phase behaviour. The reactor was purged with a slow flow of CO 2 for 20 min, after which time the vessel was filled with liquid CO 2 (T=27° C., P=77 bar) and stirring was commenced using a PTFE-coated magnetic stir bar. Under these initial conditions, the monomer mixture was emulsified in the liquid CO 2 phase, and the reaction mixture existed as a uniform, white opaque emulsion. The reactor was heated to achieve the required polymerisation conditions (65° C., P=286±10 bar) and polymerisation was carried out. The emulsion persisted during polymerisation and a uniform white appearance was observed throughout. The reactor was left stirring at 65° C. for 24 h, after which the system was cooled to ambient temperature. The CO 2 was vented slowly though acetone to trap any polymer/monomer that might otherwise escape during venting. The polymer was removed from the reactor as a dry, white, free-flowing powder. The reactor was then rinsed with acetone to collect any residual solids. The same purification procedures were used as for Example 19. There was no apparent weight loss after the washing procedure, and no soluble polymerfraction was detected. The purified polymer was isolated as a white powder (1.90 g, 95%). Found: C, 88.3; H, 7.9; Calculated: C, 91.9; H, 8.0%. IR (KBr)/cm −1 : 3450, 3018, 2964, 2925, 1603, 1511, 1486, 1449, 903, 834, 795, 710.

Copolymerisation of 1, 4+9 in the Presence of Surfactant 10

A mixture of monomers 1 (1.28 g), 4 (0.32 g), 9 (0.40 g), AlBN (0.16 g) and surfactant 10 (60 mg) was added to a 10 mL high pressure reactor, equipped with a sapphire window for the observation of phase behaviour. The reactor was purged with a slow flow of CO 2 for 20 min, after which time the vessel was filled with liquid CO 2 (T=25° C., P=102 bar) and stirring was commenced using a PTFEcoated magnetic stir bar. Under these initial conditions, the monomer mixture was emulsified in the liquid CO 2 phase, and the reaction mixture existed as a uniform, white opaque emulsion. The reactor was heated to achieve the required polymerisation conditions (65° C., P=328±10 bar) and polymerisation was carried out. The emulsion persisted during polymerisation and a uniform white appearance was observed throughout. The reactor was left stirring at 65° C. for 24 h, after which the system was cooled to ambient temperature. The CO 2 was vented slowly though acetone to trap any polymer/monomer that might otherwise escape during venting. The polymer was removed from the reactor as a dry, white, free-flowing powder. The same purification procedures were used as for Example 19. The purified polymer was isolated as a white powder (1.94 g, 97%). Found: C, 80.4; H, 7.6; Calculated: C, 84.8; H, 7.8%. IR (KBr)/cm −1 : 3047, 3016, 2967, 2931, 1700,1602, 1449, 1214, 907, 799, 712.

Copolymerisation of 1, 4+9 in the Presence of Surfactant 10 and Disperse Red 1 (11)

A mixture of monomers 1 (1.28 g), 4 (0.32 g) and 9 (0.40 g), AlBN (0.16 g), Disperse Red 1 (20 mg), and surfactant 10 (60 mg) was added to a 10 mL high pressure reactor, equipped with a sapphire window for the observation of phase behaviour. The reactor was purged with a slow flow of CO 2 for 20 min, after which time the vessel was filled with liquid CO 2 (T=28° C., P=85 bar) and stirring was commenced using a PTFE-coated magnetic stir bar. Under these initial conditions, the monomer mixture was emulsified in the liquid CO 2 phase, and the reaction mixture existed as a uniform, pale red, opaque emulsion. Nearly all of the dye, Disperse Red 1, which is insoluble in CO 2 under these conditions, was dissolved in the emulsified monomer phase. The reactor was heated to achieve the required polymerisation conditions (65° C., P=326±10 bar) and polymerisation was carried out. The emulsion persisted during polymerisation and a uniform opaque red appearance was observed throughout. The reactor was left stirring at 65° C. for 24 h, after which the system was cooled to ambient temperature. The CO 2 was vented slowly though acetone to trap any polymer/monomer that might otherwise escape during venting. The polymer was removed from the reactor as a dry, pale red, free-flowing powder. (1.90 g, 92%). Found: C, 80.4; H, 7.6; N, 1.5; Calculated: C, 84.1; H, 7.8; N, 0.5%. IR (KBr)/cm −1 : 3047, 3016, 2967, 2931, 1700, 1602, 1449, 1214, 907, 799, 712. The pale red polymer was treated by Soxhlet extraction (95° C., toluene, 72 h). After extraction, an off-white polymer was obtained, demonstrating that a large percentage of the dye was extractable from the cross-linked matrix.

Scanning Electron Microscopy showed that the polymer products obtained in each of Examples 19 to 32 were substantially uniform, substantially spherical particles.