1-bromo-4-(2-methylpropyl)benzene

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: To a mixture of 1.78 g (10 milliMoles) of N-bromosuccinimide in 20 ml of liquid sulfur dioxide at -30° C. is added 1.57 ml (10.0 mMoles) of isobutylbenzene. The mixture is stirred at -30° to -18° for 65 minutes, then worked up as above. Assay gives only 2% p-bromoisobutylbenzene and 88% recovered starting isobutylbenzene, indicating that the reaction with NBS is very slow at this temperature.

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

Procedure: Bromine chloride (Dow, 1.12 g, 9.7 millimMoles) is condensed in a tube using Dry ice cooling, then it is diluted with 20 ml of liquid sulfur dioxide and the resultant solution is cooled to -72° C. Isobutylbenzene (1.57 ml, 10.0 milliMoles) is added, and the resultant mixture is stirred at -70° for 65 minutes before quenched with 1.2 grams (10.9 milliMoles) of resorcinol. Workup and analysis as above gives 8% isobutylbenzene, 6% ortho-, and 83% para-bromoiso-butylbenzene. This result indicates that the bromination with bromine chloride is faster than that with molecular bromine, and the extent of ortho-bromination is somewhat higher. condensed in a tube

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

Procedure: To a mixture of 1.78 g (10 milliMoles) of N-bromosuccinimide in 20 ml of liquid sulfur dioxide at -30° C. is added 1.57 ml (10.0 mMoles) of isobutylbenzene. The mixture is stirred at -30° to -18° for 65 minutes, then worked up as above. Assay gives only 2% p-bromoisobutylbenzene and 88% recovered starting isobutylbenzene, indicating that the reaction with NBS is very slow at this temperature.

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

Procedure: Bromine chloride (Dow, 1.12 g, 9.7 milliMoles) is condensed in a tube using Dry Ice cooling, then it is diluted with 20 ml of liquid sulfur dioxide and the resultant solution is cooled to -72° C. Isobutylbenzene (1.57 ml, 10.0 milliMoles) is added, and the resultant mixture is stirred at -70° for 65 minutes before quenched with 1.2 grams (10.9 milliMoles) of resorcinol. Workup and analysis as above gives 8% isobutylbenzene, 6% ortho-, and 83% para-bromoiso-butylbenzene. This result indicates that the bromination with bromine chloride is faster than that with molecular bromine, and the extent of ortho-bromination is somewhat higher. condensed in a tube

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

Procedure: Bromine chloride (Dow, 1.12 g, 9.7 milliMoles) is condensed in a tube using Dry Ice cooling, then it is diluted with 20 ml of liquid sulfur dioxide and the resultant solution is cooled to -72° C. Isobutylbenzene (1.57 ml, 10.0 milliMoles) is added, and the resultant mixture is stirred at -70° for 65 minutes before quenched with 1.2 grams (10.9 milliMoles) of resorcinol. Workup and analysis as above gives 8% isobutylbenzene, 6% ortho-, and 83% para-bromoiso-butylbenzene. This result indicates that the bromination with bromine chloride is faster than that with molecular bromine, and the extent of ortho-bromination is somewhat higher. condensed in a tube

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

Procedure: To a suspension of 0.68 g (28.15 mmol) of magnesium turnings in 50 mL of tetrahydrofuran under argon, a crystal of iodine was added and a solution of 4-bromo-isobutylbenzene (6.0 g, 28.15 mmol) in 25 mL of tetrahydrofuran was added at such a rate that a gentle reflux was maintained. The mixture was refluxed for an additional 1 hour, cooled to room temperature and added in portions over 15 min to a solution of trimethylborate (2.93 g, 28.15 mmol) in 50 mL of ether at -78° C. under argon. After 30 min at -78° C., the solution was warmed to room temperature, stirred for 90 minutes and 10% aqueous hydrochloric acid (100 mL) was added. After 10 minutes, the solution was extracted with ether (3×100 mL) and the combined ether extracts were extracted with 1M sodium hydroxide (3×100 mL). The aqueous extracts were acidified with dilute hydrochloric acid to pH 2 and extracted with ether (3×100 mL). The combined ether extracts were washed once with water (100 mL), dried and evaporated to afford 3.5 g of a white solid. Crystallization from ether/hexanes provided 2.3 g (46%) of compound A as a white solid in two crops, m.p. 134°-135° C. a gentle reflux was maintained The mixture was refluxed for an additional 1 hour the solution was warmed to room temperature After 10 minutes the solution was extracted with ether (3×100 mL) the combined ether extracts were extracted with 1M sodium hydroxide (3×100 mL) extracted with ether (3×100 mL) The combined ether extracts were washed once with water (100 mL) dried evaporated

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

Procedure: To a mixture of 1.78 g (10 milliMoles) of N-bromosuccinimide in 20 ml of liquid sulfur dioxide at -30° C. is added 1.57 ml (10.0 mMoles) of isobutylbenzene. The mixture is stirred at -30° to -18° for 65 minutes, then worked up as above. Assay gives only 2% p-bromoisobutylbenzene and 88% recovered starting isobutylbenzene, indicating that the reaction with NBS is very slow at this temperature.

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

Procedure: To a mixture of 1.78 g (10 milliMoles) of N-bromosuccinimide in 20 ml of liquid sulfur dioxide at -30° C. is added 1.57 ml (10.0 mMoles) of isobutylbenzene. The mixture is stirred at -30° to -18° for 65 minutes, then worked up as above. Assay gives only 2% p-bromoisobutylbenzene and 88% recovered starting isobutylbenzene, indicating that the reaction with NBS is very slow at this temperature.

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

Procedure: Bromine chloride (Dow, 1.12 g, 9.7 millimMoles) is condensed in a tube using Dry ice cooling, then it is diluted with 20 ml of liquid sulfur dioxide and the resultant solution is cooled to -72° C. Isobutylbenzene (1.57 ml, 10.0 milliMoles) is added, and the resultant mixture is stirred at -70° for 65 minutes before quenched with 1.2 grams (10.9 milliMoles) of resorcinol. Workup and analysis as above gives 8% isobutylbenzene, 6% ortho-, and 83% para-bromoiso-butylbenzene. This result indicates that the bromination with bromine chloride is faster than that with molecular bromine, and the extent of ortho-bromination is somewhat higher. condensed in a tube

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

Procedure: Bromine chloride (Dow, 1.12 g, 9.7 millimMoles) is condensed in a tube using Dry ice cooling, then it is diluted with 20 ml of liquid sulfur dioxide and the resultant solution is cooled to -72° C. Isobutylbenzene (1.57 ml, 10.0 milliMoles) is added, and the resultant mixture is stirred at -70° for 65 minutes before quenched with 1.2 grams (10.9 milliMoles) of resorcinol. Workup and analysis as above gives 8% isobutylbenzene, 6% ortho-, and 83% para-bromoiso-butylbenzene. This result indicates that the bromination with bromine chloride is faster than that with molecular bromine, and the extent of ortho-bromination is somewhat higher. condensed in a tube