lead(2+);diacetate;trihydrate

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of (2,6-dibromo-4-fluoro-phenyl)-thiourea (0.300 g, 0.920 mmol) and 1M aq. KOH (7.23 mL) was heated to 100° C. Lead (II) acetate trihydrate (0.400 g, 1.05 mmol) in water (2 mL) was then added. The mixture was heated at 100° C. for another 10 minutes while a precipitate was observed. The mixture was cooled to 0° C. and filtered to provide a clear colorless solution. The filtrate was acidified to pH 5 with acetic acid. The precipitate was collected by filtration to yield titled compound (0.170 g, 63%). 1H NMR (400 MHz, DMSO-d6): 7.80-7.78 (m, 2H). The mixture was cooled to 0° C. filtered to provide a clear colorless solution The precipitate was collected by filtration

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 2.4 g of lead diacetate-trihydrate in 180 ml of dimethylformamide and 24 ml of acetic anhydride was added 4.6 g of (20S)-20-methylpregn-5-ene-1α,3β,21-triol. After standing at room temperature for 24 hr., the mixture was poured onto 1 kg of a 3:1 water--ice mixture and then extracted with ether. The ether extract was washed with water, dried (Na2SO4) and evaporated by means of a water aspirator. The residue was chromatographed on 100 g of silica gel. Elution with 1:1 hexane--ether afforded 1.14 g (20%) of (20S)-3β,21-diacetyloxy-20-methylpregn-5-en-1α-ol, mp 148°-149°. Elution with ether gave first 0.24 g (4.6%) of (20S)-3β-acetyloxy-20-methylpregn-5-ene-1α,21-diol, mp 202°-203° and then 2.94 g (57%) of (20S)-21-acetyloxy-20-methylpregn-5-ene-1α,3β -diol, mp 121°-121°. Finally, elution with ethyl acetate afforded 0.79 g (17%) of starting triol. ice mixture and then extracted with ether The ether extract was washed with water dried (Na2SO4) evaporated by means of a water aspirator The residue was chromatographed on 100 g of silica gel Elution with 1:1 hexane

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 2.4 g of lead diacetate-trihydrate in 180 ml of dimethylformamide and 24 ml of acetic anhydride was added 4.6 g of (20S)-20-methylpregn-5-ene-1α,3β,21-triol. After standing at room temperature for 24 hr., the mixture was poured onto 1 kg of a 3:1 water--ice mixture and then extracted with ether. The ether extract was washed with water, dried (Na2SO4) and evaporated by means of a water aspirator. The residue was chromatographed on 100 g of silica gel. Elution with 1:1 hexane--ether afforded 1.14 g (20%) of (20S)-3β,21-diacetyloxy-20-methylpregn-5-en-1α-ol, mp 148°-149°. Elution with ether gave first 0.24 g (4.6%) of (20S)-3β-acetyloxy-20-methylpregn-5-ene-1α,21-diol, mp 202°-203° and then 2.94 g (57%) of (20S)-21-acetyloxy-20-methylpregn-5-ene-1α,3β -diol, mp 121°-121°. Finally, elution with ethyl acetate afforded 0.79 g (17%) of starting triol. ice mixture and then extracted with ether The ether extract was washed with water dried (Na2SO4) evaporated by means of a water aspirator The residue was chromatographed on 100 g of silica gel Elution with 1:1 hexane

Conditions: temp:85.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Lead oleate was prepared as follows: lead acetate trihydrate (1 mmol) was mixed with ODE (4 mL) and oleic acid (1.3 mL) in a 50-mL three-neck flask. The mixture was degassed under vacuum (˜50 mTorr) at RT for 10 minutes and then gradually heated to 85° C. and kept for 1 hour to further remove the water and acetic acid. After the mixture turned colorless, the vacuum was removed and the lead-oleate solution was cooled to room temperature. The lead-oleate solution was mixed with TOP (8 mL) and SeO2 (1 mmol). Under argon flow and with stirring, the resulting mixture was heated to 180° C. After 5 min at the temperature, the reaction was terminated by cooling the reaction solution to room temperature. The resulting PbSe nanocrystals were precipitated from the reaction solution using acetone and redispersed in toluene. The mixture was degassed under vacuum (˜50 mTorr) at RT for 10 minutes to further remove the water and acetic acid the vacuum was removed the lead-oleate solution was cooled to room temperature the resulting mixture was heated to 180° C After 5 min at the temperature the reaction was terminated by cooling the reaction solution to room temperature The resulting PbSe nanocrystals were precipitated from the reaction solution redispersed in toluene

Conditions: temp:85.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Lead oleate was prepared as follows: lead acetate trihydrate (1 mmol) was mixed with ODE (4 mL) and oleic acid (1.3 mL) in a 50-mL three-neck flask. The mixture was degassed under vacuum (˜50 mTorr) at RT for 10 minutes and then gradually heated to 85° C. and kept for 1 hour to further remove the water and acetic acid. After the mixture turned colorless, the vacuum was removed and the lead-oleate solution was cooled to room temperature. The lead-oleate solution was mixed with TOP (8 mL) and SeO2 (1 mmol). Under argon flow and with stirring, the resulting mixture was heated to 180° C. After 5 min at the temperature, the reaction was terminated by cooling the reaction solution to room temperature. The resulting PbSe nanocrystals were precipitated from the reaction solution using acetone and redispersed in toluene. The mixture was degassed under vacuum (˜50 mTorr) at RT for 10 minutes to further remove the water and acetic acid the vacuum was removed the lead-oleate solution was cooled to room temperature the resulting mixture was heated to 180° C After 5 min at the temperature the reaction was terminated by cooling the reaction solution to room temperature The resulting PbSe nanocrystals were precipitated from the reaction solution redispersed in toluene

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a mixture of 5.3 g (30 mmol) of 4-phenyl-1,2,4-triazolidine-3,5-dione and 22.7 g (60 mmol) of lead diacetate trihydrate in 200 ml of chloroform was added dropwise over a 15 minute period 45.9 g (450 mmol) of acetic anhydride. The mixture was stirred at room temperature. After 25 hours the pale yellow solution was washed with three 100 ml portions of water and three 75 ml portions of 10% sodium carbonate. The carbonate washings were acidified with concentrated hydrochloric acid. No precipitate was produced. The chloroform solution was dried (Na2SO4) and evaporated under reduced pressure to give a solid-liquid residue. The residue was filtered and the filtered solid was washed with 25 ml of 95% ethanol to give 2.75 g (35.1%) of the 1,2,4-triazolidine-3,5-dione product as a white solid. An additional quantity of the product precipitated from the ethanol filtrate. This solid was filtered to give an additional 1.20 g (15.3%) of the 1,2,4=triazolidine-3,5-dione product (50.4% total yield). The solids were recrystallized from 95% ethanol to give pure 1,2-dimethylcarbonyl-4-phenyl-1,2,4-triazolidine-3,5-dione: m.p. 169°-170.5° C.; IR (Nujol) 1750, 1732 (shoulder), 1714 (shoulder) cm-1 (CO); 1H NMR (60 MHz, CDCl3)δ7.80(s, 5H), 2.55 (s, 6H); Found: C, 55.2; H, 4.45; N, 16.0; C12H11N3O4 requires C, 55.2; H, 4.2; N, 16.0. After 25 hours the pale yellow solution was washed with three 100 ml portions of water and three 75 ml portions of 10% sodium carbonate No precipitate was produced The chloroform solution was dried (Na2SO4) evaporated under reduced pressure to give a solid-liquid residue The residue was filtered the filtered solid was washed with 25 ml of 95% ethanol

Conditions: temp:150.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In one example, 0.76 g of lead acetate trihydrate and 2 ml of oleic acid were added to 10 ml of diphenyl ether solution and heated to about 150° C. for 30 min. under nitrogen condition to form lead oleate. After cooling to 60° C., the solution was mixed with 0.67 ml of 1M trioctylphosphine selenide solution in trioctylphosphine, resulting in a precursor stock solution for PbSe nanowires (“Solution A”). Reaction was carried out by injecting the stock solution containing the nanowire precursors lead oleate and trioctylphosphine selenide into another solution (“Solution B”) that was heated to about 250° C. Injecting Solution A into the pre-heated Solution B allows the precursor solution to be rapidly heated to a temperature necessary for nucleation to take place. In one embodiment, Solution B contains about 15 ml phenyl ether. Upon mixing Solution A with phenyl ether, nucleation was initiated and resulted in the formation of PbSe nanocrystals, and the temperature of the solution mixture also decreased to about 180° C.

Conditions: temp:150.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In one example, 0.76 g of lead acetate trihydrate and 2 ml of oleic acid were added to 10 ml of diphenyl ether solution and heated to about 150° C. for 30 min. under nitrogen condition to form lead oleate. After cooling to 60° C., the solution was mixed with 0.67 ml of 1M trioctylphosphine selenide solution in trioctylphosphine, resulting in a precursor stock solution for PbSe nanowires (“Solution A”). Reaction was carried out by injecting the stock solution containing the nanowire precursors lead oleate and trioctylphosphine selenide into another solution (“Solution B”) that was heated to about 250° C. Injecting Solution A into the pre-heated Solution B allows the precursor solution to be rapidly heated to a temperature necessary for nucleation to take place. In one embodiment, Solution B contains about 15 ml phenyl ether. Upon mixing Solution A with phenyl ether, nucleation was initiated and resulted in the formation of PbSe nanocrystals, and the temperature of the solution mixture also decreased to about 180° C.

Conditions: temp:150.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In one example, 0.76 g of lead acetate trihydrate and 2 ml of oleic acid were added to 10 ml of diphenyl ether solution and heated to about 150° C. for 30 min. under nitrogen condition to form lead oleate. After cooling to 60° C., the solution was mixed with 0.67 ml of 1M trioctylphosphine selenide solution in trioctylphosphine, resulting in a precursor stock solution for PbSe nanowires (“Solution A”). Reaction was carried out by injecting the stock solution containing the nanowire precursors lead oleate and trioctylphosphine selenide into another solution (“Solution B”) that was heated to about 250° C. Injecting Solution A into the pre-heated Solution B allows the precursor solution to be rapidly heated to a temperature necessary for nucleation to take place. In one embodiment, Solution B contains about 15 ml phenyl ether. Upon mixing Solution A with phenyl ether, nucleation was initiated and resulted in the formation of PbSe nanocrystals, and the temperature of the solution mixture also decreased to about 180° C.

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Lead (II) acetate trihydrate (0.759 g, 2.0 mmol) and 4-nitrobenzyl mercaptan (0.745 g, 4.4 mmol) were stirred together in methanol (24 cm3) solution at room temperature. After 1 h, the products were filtered and the residue was washed with a small volume of cold methanol. The residue was dried in vacuo over calcium chloride and then suspended in dry acetonitrile (20 cm3). Following the evaporation of the solvent under reduced pressure, the residue was suspended in dry benzene (20 cm3) and the solvent was again evaporated under reduced pressure. Finally, the residue was re-suspended in dry benzene (64 cm3) and N-bromosuccinimide (0.783 g, 4.4 mmol) was added in three portions over a period of 45 min to the stirred suspension at room temperature. The reactants were then heated at 50° C., under an atmosphere of argon, for 14 h. The cooled products were filtered and the filtrate was evaporated under reduced pressure to give a solid. The latter material was crystallized from ethyl acetate--hexane to give N-(4-nitrobenzylmercapto)succinimide 18 (0.76 g, 65%) (Found: C, 49.85; H, 3.8; N, 10.4. C11H10N2O4S requires: C, 49.6; H, 3.8; N, 10.5%), m.p. 146°-148° C.; δH [CDCl3 ] 2.73 (4 H, s), 4.18 (2 H, s), 7.50 (2 H, m), 8.17 (2 H, m); δC [CDCl3 ] 28.4, 40.5, 123.8, 130.3, 141.9, 147.5, 176.2. the products were filtered the residue was washed with a small volume of cold methanol The residue was dried in vacuo over calcium chloride the evaporation of the solvent under reduced pressure the solvent was again evaporated under reduced pressure The cooled products were filtered the filtrate was evaporated under reduced pressure to give a solid The latter material was crystallized from ethyl acetate

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of (2,6-dibromo-4-fluoro-phenyl)-thiourea (0.300 g, 0.920 mmol) and 1M aq. KOH (7.23 mL) was heated to 100° C. Lead (II) acetate trihydrate (0.400 g, 1.05 mmol) in water (2 mL) was then added. The mixture was heated at 100° C. for another 10 minutes while a precipitate was observed. The mixture was cooled to 0° C. and filtered to provide a clear colorless solution. The filtrate was acidified to pH 5 with acetic acid. The precipitate was collected by filtration to yield titled compound (0.170 g, 63%). 1H NMR (400 MHz, DMSO-d6): 7.80-7.78 (m, 2H). The mixture was cooled to 0° C. filtered to provide a clear colorless solution The precipitate was collected by filtration

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of (2,6-dibromo-4-fluoro-phenyl)-thiourea (0.300 g, 0.920 mmol) and 1M aq. KOH (7.23 mL) was heated to 100° C. Lead (II) acetate trihydrate (0.400 g, 1.05 mmol) in water (2 mL) was then added. The mixture was heated at 100° C. for another 10 minutes while a precipitate was observed. The mixture was cooled to 0° C. and filtered to provide a clear colorless solution. The filtrate was acidified to pH 5 with acetic acid. The precipitate was collected by filtration to yield titled compound (0.170 g, 63%). 1H NMR (400 MHz, DMSO-d6): 7.80-7.78 (m, 2H). The mixture was cooled to 0° C. filtered to provide a clear colorless solution The precipitate was collected by filtration