2-(4-bromophenyl)-4,5-dimethyl-3-oxido-1,3-oxazol-3-ium

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

Procedure: A solution of 4,5-dimethyl-2-(4-bromophenyl)-oxazole oxide (96.6 g, 0.36 mol) in CHCl3 (0.90 L) was treated dropwise with phosphorous oxychloride (61.1 g, 0.40 mol) allowing the reaction to exotherm and then was stirred at reflux for 30 min. The reaction was then cooled to room temperature and washed with water (2×1 L). The combined aqueous washes were back extracted with CH2Cl2 (2×400 mL). The organic layers were dried (MgSO4), and the solvent removed in vacuo to give crude product that was recrystallized from hot hexanes (300 mL), decanting the hot supernate away from a dark oily material. The remaining dark oil was agitated in additional hot hexanes (200 mL) and the combined supernates were cooled to 0° C. to crystallize the product which was isolated by filtration to give 74.2 g (72%) of 2-(4-bromophenyl-4-(chloromethyl)-5-methyloxazole as a lime-green powder: Rf=0.39 in 20% ethyl acetate/hexanes; 1H NMR (500 MHz, CDCl3) 7.88-7.86 (m, 2H), 7.59-7.56 (m, 2H), 4.54 (s, 2H), 2.42 (s, 3H); 13C (125 MHz, CDCl3) 159.2, 146.9, 133.2, 132.0, 127.6, 126.1, 124.7,37.1, 11.5; IR (KBr) 2970, 1633, 1599, 1481, 1401, 1258, 1117, 1008 cm−1; UV (EtOH)max281 nm (21349); HRMS (FAB) m/z calculated for C11H1079BrClNO: 285,9634, found 285.9641; Anal. Calculated for C11H9ClBrNO: C, 46.11; H, 3.17; N, 4.89; Cl, 12.37; Br, 27.88. Found C, 46.28; H 3.07; N, 4.81; Cl, 12.36; Br, 27.88. the reaction at reflux for 30 min washed with water (2×1 L) The combined aqueous washes were back extracted with CH2Cl2 (2×400 mL) The organic layers were dried (MgSO4) the solvent removed in vacuo to give crude product that was recrystallized from hot hexanes (300 mL) decanting the hot supernate away from a dark oily material The remaining dark oil was agitated in additional hot hexanes (200 mL) the combined supernates were cooled to 0° C. to crystallize the product which was isolated by filtration

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

Procedure: A solution of 2,3-butanedione monooxime (50 g, 0.49 mol) and 4-bromobenzaldehyde (101 g, 0.54 mol) in acetic acid (500 mL) was cooled to 0° C. and then gaseous HCl was bubbled through the solution for 35 min while the reaction was stirred in an ice bath. Diethyl ether (500 mL) was then added to the reaction to precipitate the product and the resultant slurry stirred 45 min at 0° C. before being filtered. The solids were rinsed with Et2O (50 mL), taken up in water (1 L) and conc. NH4OH (60 mL) added to the slurry. This mixture was extracted with CHCl3, the organic layer was dried (MgSO4), and the solvent removed in vacuo to give 97.4 g (74%) of 4,5-dimethyl-2-(4-bromophenyl)-oxazole oxide as a white solid. The compound should be used directly within 24-48 h: 1H NMR (500 MHz, CDCl3) 8.34 (d, J=9.0 Hz, 2H), 7.61 (d, J=9.0 Hz, 2H), 2.35 (s, 3H), 2.20 (s, 3H); 13C (125 MHz, CDCl3) 142.1, 131.9, 129.5, 126.3, 124.1, 122.2, 11.1, 6.2; IR (KBr) 1685, 1529, 1418, 1377, 1233, 1165 cm−1; UV (EtOH) max307 nm (24371); HRMS (TOF) m/z calculated for C11H1179BrNO2: 267.997, found 267.9951. gaseous HCl was bubbled through the solution for 35 min while the reaction Diethyl ether (500 mL) was then added to the reaction to precipitate the product the resultant slurry stirred 45 min at 0° C. before being filtered The solids were rinsed with Et2O (50 mL) conc. NH4OH (60 mL) added to the slurry This mixture was extracted with CHCl3 the organic layer was dried (MgSO4) the solvent removed in vacuo

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

Procedure: A solution of 4,5-dimethyl-2-(4-bromophenyl)-oxazole oxide (96.6 g, 0.36 mol) in CHCl3 (0.90 L) was treated dropwise with phosphorous oxychloride (61.1 g, 0.40 mol) allowing the reaction to exotherm and then was stirred at reflux for 30 min. The reaction was then cooled to room temperature and washed with water (2×1 L). The combined aqueous washes were back extracted with CH2Cl2 (2×400 mL). The organic layers were dried (MgSO4), and the solvent removed in vacuo to give crude product that was recrystallized from hot hexanes (300 mL), decanting the hot supernate away from a dark oily material. The remaining dark oil was agitated in additional hot hexanes (200 mL) and the combined supernates were cooled to 0° C. to crystallize the product which was isolated by filtration to give 74.2 g (72%) of 2-(4-bromophenyl-4-(chloromethyl)-5-methyloxazole as a lime-green powder: Rf=0.39 in 20% ethyl acetate/hexanes; 1H NMR (500 MHz, CDCl3) 7.88–7.86 (m, 2H), 7.59–7.56 (m, 2H), 4.54 (s, 2H), 2.42 (s, 3H); 13C (125 MHz, CDCl3) 159.2, 146.9, 133.2, 132.0, 127.6, 126.1, 124.7, 37.1, 11.5; IR (KBr) 2970, 1633, 1599, 1481, 1401, 1258, 1117, 1008 cm−1; UV (EtOH)max 281 nm (21349); HRMS (FAB) m/z calculated for C11H1079BrClNO: 285.9634, found 285.9641; Anal. Calculated for C11H9ClBrNO: C, 46.11; H, 3.17; N, 4.89; Cl, 12.37; Br, 27.88. Found C, 46.28; H 3.07; N, 4.81; Cl, 12.36; Br, 27.88. the reaction at reflux for 30 min washed with water (2×1 L) The combined aqueous washes were back extracted with CH2Cl2 (2×400 mL) The organic layers were dried (MgSO4) the solvent removed in vacuo to give crude product that was recrystallized from hot hexanes (300 mL) decanting the hot supernate away from a dark oily material The remaining dark oil was agitated in additional hot hexanes (200 mL) the combined supernates were cooled to 0° C. to crystallize the product which was isolated by filtration

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

Procedure: A solution of 2,3-butanedione monooxime (50 g, 0.49 mol) and 4-bromo-benzaldehyde (101 g, 0.54 mol) in acetic acid (500 mL) was cooled to 0° C. and then gaseous HCl was bubbled through the solution for 35 min while the reaction was stirred in an ice bath. Diethyl ether (500 mL) was then added to the reaction to precipitate the product and the resultant slurry stirred 45 min at 0° C. before being filtered. The solids were rinsed with Et2O (50 mL), taken up in water (1 L) and conc. NH4OH (60 mL) added to the slurry. This mixture was extracted with CHCl3, the organic layer was dried (MgSO4), and the solvent removed in vacuo to give 97.4 g (74%) of 4,5-dimethyl-2-(4-bromophenyl)-oxazole oxide as a white solid. The compound should be used directly within 24–48 h: 1H NMR (500 MHz, CDCl3) 8.34 (d, J=9.0 Hz, 2H), 7.61 (d, J=9.0 Hz, 2H), 2.35 (s, 3H), 2.20 (s, 3H); 13C (125 MHz, CDCl3) 142.1, 131.9, 129.5, 126.3, 124.1, 122.2, 11.1, 6.2; IR (KBr) 1685, 1529, 1418, 1377, 1233, 1165 cm−1; UV (EtOH)max 307 nm (24371); HRMS (TOF) m/z calculated for C11H1179BrNO2: 267.997, found 267.9951. gaseous HCl was bubbled through the solution for 35 min while the reaction Diethyl ether (500 mL) was then added to the reaction to precipitate the product the resultant slurry stirred 45 min at 0° C. before being filtered The solids were rinsed with Et2O (50 mL) conc. NH4OH (60 mL) added to the slurry This mixture was extracted with CHCl3 the organic layer was dried (MgSO4) the solvent removed in vacuo

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

Procedure: A solution of 2,3-butanedione monooxime (50 g, 0.49 mol) and 4-bromobenzaldehyde (101 g, 0.54 mol) in acetic acid (500 mL) was cooled to 0° C. and then gaseous HCl was bubbled through the solution for 35 min while the reaction was stirred in an ice bath. Diethyl ether (500 mL) was then added to the reaction to precipitate the product and the resultant slurry stirred 45 min at 0° C. before being filtered. The solids were rinsed with Et2O (50 mL), taken up in water (1 L) and conc. NH4OH (60 mL) added to the slurry. This mixture was extracted with CHCl3, the organic layer was dried (MgSO4), and the solvent removed in vacuo to give 97.4 g (74%) of 2-(4-bromophenyl)-4,5-dimethyloxazole-3-oxide as a white solid. The compound should be used directly with 24-48 h: 1H NMR (500 MHz, CDCl3) δ 8.34 (d, J=9.0 Hz, 2H), 7.61 (d, J=9.0 Hz, 2H), 2.35 (s, 3H), 2.20 (s, 3H); 13C (125 MHz, CDCl3) δ 142.1, 131.9, 129.5, 126.3, 124.1, 122.2, 11.1, 6.2; IR (KBr) 1685, 1529, 1418, 1377, 1233, 1165 cm−1; UV (EtOH) λmax 307 nm (ε 24371); HRMS (TOF) m/z calc'd for C11H1179BrNO2: 267.997, found 267.9951. gaseous HCl was bubbled through the solution for 35 min while the reaction Diethyl ether (500 mL) was then added to the reaction to precipitate the product the resultant slurry stirred 45 min at 0° C. before being filtered The solids were rinsed with Et2O (50 mL) conc. NH4OH (60 mL) added to the slurry This mixture was extracted with CHCl3 the organic layer was dried (MgSO4) the solvent removed in vacuo

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

Procedure: A solution of 4,5-dimethyl-2-(4-bromophenyl)-oxazole oxide (96.6 g, 0.36 mol) in CHCl3 (0.90 L) was treated dropwise with phosphorous oxychloride (61.1 g, 0.40 mol) allowing the reaction to exotherm and then was stirred at reflux for 30 min. The reaction was then cooled to room temperature and washed with water (2×1 L). The combined aqueous washes were back extracted with CH2Cl2 (2×400 mL). The organic layers were dried (MgSO4), and the solvent removed in vacuo to give crude product that was recrystallized from hot hexanes (300 mL), decanting the hot supernate away from a dark oily material. The remaining dark oil was agitated in additional hot hexanes (200 mL) and the combined supernates were cooled to 0° C. to crystallize the product which was isolated by filtration to give 74.2 g (72%) of 2-(4-bromophenyl-4-(chloromethyl)-5-methyloxazole as a lime-green powder: Rf=0.39 in 20% ethyl acetate/hexanes; 1H NMR (500 MHz, CDCl3) 7.88-7.86 (m, 2H), 7.59-7.56 (m, 2H), 4.54 (s, 2H), 2.42 (s, 3H); 13C (125 MHz, CDCl3) 159.2, 146.9, 133.2, 132.0, 127.6, 126.1, 124.7,37.1, 11.5; IR (KBr) 2970, 1633, 1599, 1481, 1401, 1258, 1117, 1008 cm−1; UV (EtOH)max281 nm (21349); HRMS (FAB) m/z calculated for C11H1079BrClNO: 285,9634, found 285.9641; Anal. Calculated for C11H9ClBrNO: C, 46.11; H, 3.17; N, 4.89; Cl, 12.37; Br, 27.88. Found C, 46.28; H 3.07; N, 4.81; Cl, 12.36; Br, 27.88. the reaction at reflux for 30 min washed with water (2×1 L) The combined aqueous washes were back extracted with CH2Cl2 (2×400 mL) The organic layers were dried (MgSO4) the solvent removed in vacuo to give crude product that was recrystallized from hot hexanes (300 mL) decanting the hot supernate away from a dark oily material The remaining dark oil was agitated in additional hot hexanes (200 mL) the combined supernates were cooled to 0° C. to crystallize the product which was isolated by filtration

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

Procedure: A solution of 2,3-butanedione monooxime (50 g, 0.49 mol) and 4-bromobenzaldehyde (101 g, 0.54 mol) in acetic acid (500 mL) was cooled to 0° C. and then gaseous HCl was bubbled through the solution for 35 min while the reaction was stirred in an ice bath. Diethyl ether (500 mL) was then added to the reaction to precipitate the product and the resultant slurry stirred 45 min at 0° C. before being filtered. The solids were rinsed with Et2O (50 mL), taken up in water (1 L) and conc. NH4OH (60 mL) added to the slurry. This mixture was extracted with CHCl3, the organic layer was dried (MgSO4), and the solvent removed in vacuo to give 97.4 g (74%) of 4,5-dimethyl-2-(4-bromophenyl)-oxazole oxide as a white solid. The compound should be used directly within 24-48 h: 1H NMR (500 MHz, CDCl3) 8.34 (d, J=9.0 Hz, 2H), 7.61 (d, J=9.0 Hz, 2H), 2.35 (s, 3H), 2.20 (s, 3H); 13C (125 MHz, CDCl3) 142.1, 131.9, 129.5, 126.3, 124.1, 122.2, 11.1, 6.2; IR (KBr) 1685, 1529, 1418, 1377, 1233, 1165 cm−1; UV (EtOH) max307 nm (24371); HRMS (TOF) m/z calculated for C11H1179BrNO2: 267.997, found 267.9951. gaseous HCl was bubbled through the solution for 35 min while the reaction Diethyl ether (500 mL) was then added to the reaction to precipitate the product the resultant slurry stirred 45 min at 0° C. before being filtered The solids were rinsed with Et2O (50 mL) conc. NH4OH (60 mL) added to the slurry This mixture was extracted with CHCl3 the organic layer was dried (MgSO4) the solvent removed in vacuo

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

Procedure: A solution of 4,5-dimethyl-2-(4-bromophenyl)-oxazole oxide (96.6 g, 0.36 mol) in CHCl3 (0.90 L) was treated dropwise with phosphorous oxychloride (61.1 g, 0.40 mol) allowing the reaction to exotherm and then was stirred at reflux for 30 min. The reaction was then cooled to room temperature and washed with water (2×1 L). The combined aqueous washes were back extracted with CH2Cl2 (2×400 mL). The organic layers were dried (MgSO4), and the solvent removed in vacuo to give crude product that was recrystallized from hot hexanes (300 mL), decanting the hot supernate away from a dark oily material. The remaining dark oil was agitated in additional hot hexanes (200 mL) and the combined supernates were cooled to 0° C. to crystallize the product which was isolated by filtration to give 74.2 g (72%) of 2-(4-bromophenyl-4-(chloromethyl)-5-methyloxazole as a lime-green powder: Rf=0.39 in 20% ethyl acetate/hexanes; 1H NMR (500 MHz, CDCl3) 7.88–7.86 (m, 2H), 7.59–7.56 (m, 2H), 4.54 (s, 2H), 2.42 (s, 3H); 13C (125 MHz, CDCl3) 159.2, 146.9, 133.2, 132.0, 127.6, 126.1, 124.7, 37.1, 11.5; IR (KBr) 2970, 1633, 1599, 1481, 1401, 1258, 1117, 1008 cm−1; UV (EtOH)max 281 nm (21349); HRMS (FAB) m/z calculated for C11H1079BrClNO: 285.9634, found 285.9641; Anal. Calculated for C11H9ClBrNO: C, 46.11; H, 3.17; N, 4.89; Cl, 12.37; Br, 27.88. Found C, 46.28; H 3.07; N, 4.81; Cl, 12.36; Br, 27.88. the reaction at reflux for 30 min washed with water (2×1 L) The combined aqueous washes were back extracted with CH2Cl2 (2×400 mL) The organic layers were dried (MgSO4) the solvent removed in vacuo to give crude product that was recrystallized from hot hexanes (300 mL) decanting the hot supernate away from a dark oily material The remaining dark oil was agitated in additional hot hexanes (200 mL) the combined supernates were cooled to 0° C. to crystallize the product which was isolated by filtration

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

Procedure: A solution of 4,5-dimethyl-2-(4-bromophenyl)-oxazole oxide (96.6 g, 0.36 mol) in CHCl3 (0.90 L) was treated dropwise with phosphorous oxychloride (61.1 g, 0.40 mol) allowing the reaction to exotherm and then was stirred at reflux for 30 min. The reaction was then cooled to room temperature and washed with water (2×1 L). The combined aqueous washes were back extracted with CH2Cl2 (2×400 mL). The organic layers were dried (MgSO4), and the solvent removed in vacuo to give crude product that was recrystallized from hot hexanes (300 mL), decanting the hot supernate away from a dark oily material. The remaining dark oil was agitated in additional hot hexanes (200 mL) and the combined supernates were cooled to 0° C. to crystallize the product which was isolated by filtration to give 74.2 g (72%) of 2-(4-bromophenyl-4-(chloromethyl)-5-methyloxazole as a lime-green powder: Rf=0.39 in 20% ethyl acetate/hexanes; 1H NMR (500 MHz, CDCl3) 7.88–7.86 (m, 2H), 7.59–7.56 (m, 2H), 4.54 (s, 2H), 2.42 (s, 3H); 13C (125 MHz, CDCl3) 159.2, 146.9, 133.2, 132.0, 127.6, 126.1, 124.7, 37.1, 11.5; IR (KBr) 2970, 1633, 1599, 1481, 1401, 1258, 1117, 1008 cm−1; UV (EtOH)max 281 nm (21349); HRMS (FAB) m/z calculated for C11H1079BrClNO: 285.9634, found 285.9641; Anal. Calculated for C11H9ClBrNO: C, 46.11; H, 3.17; N, 4.89; Cl, 12.37; Br, 27.88. Found C, 46.28; H 3.07; N, 4.81; Cl, 12.36; Br, 27.88. the reaction at reflux for 30 min washed with water (2×1 L) The combined aqueous washes were back extracted with CH2Cl2 (2×400 mL) The organic layers were dried (MgSO4) the solvent removed in vacuo to give crude product that was recrystallized from hot hexanes (300 mL) decanting the hot supernate away from a dark oily material The remaining dark oil was agitated in additional hot hexanes (200 mL) the combined supernates were cooled to 0° C. to crystallize the product which was isolated by filtration

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

Procedure: A solution of 2,3-butanedione monooxime (50 g, 0.49 mol) and 4-bromo-benzaldehyde (101 g, 0.54 mol) in acetic acid (500 mL) was cooled to 0° C. and then gaseous HCl was bubbled through the solution for 35 min while the reaction was stirred in an ice bath. Diethyl ether (500 mL) was then added to the reaction to precipitate the product and the resultant slurry stirred 45 min at 0° C. before being filtered. The solids were rinsed with Et2O (50 mL), taken up in water (1 L) and conc. NH4OH (60 mL) added to the slurry. This mixture was extracted with CHCl3, the organic layer was dried (MgSO4), and the solvent removed in vacuo to give 97.4 g (74%) of 4,5-dimethyl-2-(4-bromophenyl)-oxazole oxide as a white solid. The compound should be used directly within 24–48 h: 1H NMR (500 MHz, CDCl3) 8.34 (d, J=9.0 Hz, 2H), 7.61 (d, J=9.0 Hz, 2H), 2.35 (s, 3H), 2.20 (s, 3H); 13C (125 MHz, CDCl3) 142.1, 131.9, 129.5, 126.3, 124.1, 122.2, 11.1, 6.2; IR (KBr) 1685, 1529, 1418, 1377, 1233, 1165 cm−1; UV (EtOH)max 307 nm (24371); HRMS (TOF) m/z calculated for C11H1179BrNO2: 267.997, found 267.9951. gaseous HCl was bubbled through the solution for 35 min while the reaction Diethyl ether (500 mL) was then added to the reaction to precipitate the product the resultant slurry stirred 45 min at 0° C. before being filtered The solids were rinsed with Et2O (50 mL) conc. NH4OH (60 mL) added to the slurry This mixture was extracted with CHCl3 the organic layer was dried (MgSO4) the solvent removed in vacuo

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

Procedure: A solution of 4,5-dimethyl-2-(4-bromophenyl)-oxazole oxide (96.6 g, 0.36 mol) in CHCl3 (0.90 L) was treated dropwise with phosphorous oxychloride (61.1 g, 0.40 mol) allowing the reaction to exotherm and then was stirred at reflux for 30 min. The reaction was then cooled to room temperature and washed with water (2×1 L). The combined aqueous washes were back extracted with CH2Cl2 (2×400 mL). The organic layers were dried (MgSO4), and the solvent removed in vacuo to give crude product that was recrystallized from hot hexanes (300 mL), decanting the hot supernate away from a dark oily material. The remaining dark oil was agitated in additional hot hexanes (200 mL) and the combined supernates were cooled to 0° C. to crystallize the product which was isolated by filtration to give 74.2 g (72%) of 2-(4-bromophenyl-4-(chloromethyl)-5-methyloxazole as a lime-green powder: Rf=0.39 in 20% ethyl acetate/hexanes; 1H NMR (500 MHz, CDCl3) 7.88-7.86 (m, 2H), 7.59-7.56 (m, 2H), 4.54 (s, 2H), 2.42 (s, 3H); 13C (125 MHz, CDCl3) 159.2, 146.9, 133.2, 132.0, 127.6, 126.1, 124.7, 37.1, 11.5; IR (KBr) 2970, 1633, 1599, 1481, 1401, 1258, 1117, 1008 cm−1; UV (EtOH)max 281 nm (21349); HRMS (FAB) m/z calculated for C11H1079BrClNO: 285.9634, found 285.9641; Anal. Calculated for C11H9ClBrNO: C, 46.11; H, 3.17; N, 4.89; Cl, 12.37; Br, 27.88. Found C, 46.28; H 3.07; N, 4.81; Cl, 12.36; Br, 27.88. the reaction at reflux for 30 min washed with water (2×1 L) The combined aqueous washes were back extracted with CH2Cl2 (2×400 mL) The organic layers were dried (MgSO4) the solvent removed in vacuo to give crude product that was recrystallized from hot hexanes (300 mL) decanting the hot supernate away from a dark oily material The remaining dark oil was agitated in additional hot hexanes (200 mL) the combined supernates were cooled to 0° C. to crystallize the product which was isolated by filtration

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

Procedure: A solution of 2,3-butanedione monooxime (50 g, 0.49 mol) and 4-bromo-benzaldehyde (101 g, 0.54 mol) in acetic acid (500 mL) was cooled to 0° C. and then gaseous HCl was bubbled through the solution for 35 min while the reaction was stirred in an ice bath. Diethyl ether (500 mL) was then added to the reaction to precipitate the product and the resultant slurry stirred 45 min at 0° C. before being filtered. The solids were rinsed with Et2O (50 mL), taken up in water (1 L) and conc. NH4OH (60 mL) added to the slurry. This mixture was extracted with CHCl3, the organic layer was dried (MgSO4), and the solvent removed in vacuo to give 97.4 g (74%) of 4,5-dimethyl-2-(4-bromophenyl)-oxazole oxide as a white solid. The compound should be used directly within 24-48 h: 1H NMR (500 MHz, CDCl3) 8.34 (d, J=9.0 Hz, 2H), 7.61 (d, J=9.0 Hz, 2H), 2.35 (s, 3H), 2.20 (s, 3H); 13C (125 MHz, CDCl3) 142.1, 131.9, 129.5, 126.3, 124.1, 122.2, 11.1, 6.2; IR (KBr) 1685, 1529, 1418, 1377, 1233, 1165 cm−1; UV (EtOH) max307 nm (24371); HRMS (TOF) m/z calculated for C11H1179BrNO2: 267.997, found 267.9951. gaseous HCl was bubbled through the solution for 35 min while the reaction Diethyl ether (500 mL) was then added to the reaction to precipitate the product the resultant slurry stirred 45 min at 0° C. before being filtered The solids were rinsed with Et2O (50 mL) conc. NH4OH (60 mL) added to the slurry This mixture was extracted with CHCl3 the organic layer was dried (MgSO4) the solvent removed in vacuo