ethyl 2-bromohexanoate

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

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

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

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

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

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

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: Under a nitrogen atmosphere sodium (0.148 g, 6.42 mmol) was dissolved in 50 ml of abs. ethanol and 6,7-dichloroquinoxalin-2(1H)-one (1.20 g, 5.58 mmol) (Liebigs Ann. Chem., (1982), 754) was added. The mixture was stirred until the compound dissolved, and ethyl 2-bromohexanoate (1.30 ml, 7.1 mmol) was added. The reaction mixture was refluxed for 72 h, cooled to room temperature, then poured onto crushed ice and acidified by dilute hydrochloric acid (pH=2). The precipitated compound was extracted with ethyl acetate and purified by column chromatography on silica gel (eluent 15% THF in heptane) to afford 0,21 g of 1-((1-ethoxycarbonyl)pentyl)-6,7-dichloroquinoxalin-2(1H)-one 1H-NMR(DMSO-d6):δ 0.78(t, 3H), 1.1(t, 3H), 1.15-1.35(m, 4H), 2.0-2.25(m, 2H), 4.02-4.18(m, 2H), 5.58-5.75(m, 1H), 8.02-8.36(broad, 1H), 8.18(s, 1H), 8.33(s, 1H). dissolved The reaction mixture was refluxed for 72 h poured onto crushed ice The precipitated compound was extracted with ethyl acetate purified by column chromatography on silica gel (eluent 15% THF in heptane)

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

Procedure: A quantity (30.4 g., 0.1 mole) of 3,4,5-tribromopyrazole was dissolved in 500 ml. acetone and 27.6 g. (0.2 mole) solid anhydrous potassium carbonate was added. The mixture was heated at the reflux temperature with stirring for 10 minutes and after cooling 23.0 g. (0.11 mole) ethyl 2-bromohexanoate was added. This reaction mixture was heated at the reflux temperature for 11/2 hrs., cooled, and then filtered. The solids on the filter were washed with acetone and the combined acetone filtrate and acetone washes were evaporated to dryness under reduced pressure. Distillation of the residue yielded ethyl 3,4,5-tribromo-α-butylpyrazole-1-acetate, 41.0 g. (92% yield), having a boiling point at 138° to 140° C. at 0.15 mm. mercury pressure. The mixture was heated at the reflux temperature after cooling 23.0 g This reaction mixture was heated at the reflux temperature for 11/2 hrs , cooled filtered The solids on the filter were washed with acetone the combined acetone filtrate and acetone washes were evaporated to dryness under reduced pressure Distillation of the residue

Conditions: temp:140.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 206 g (1 mol) of 2,4-di-tert-butylphenol were melted and heated to 140° C. under nitrogen. 234 g (1.03 mol) of a 30% strength NaOEt solution in EtOH and 245 g (1.1 mol) of ethyl 2-bromocaproate were metered in simultaneously in the course of 1 hour. During the addition, EtOH was distilled off. After the addition, the reaction was ended. The mixture was cooled to 90° C. and 250 ml of water were added. After separation of the phases and washing with 200 ml of water, 347 g of a viscous yellow oil of the following composition (0.3% of ethyl bromocaproate, 0.5% of residual phenol and 98% of ethyl 2-(2,4-di-tert-butylphenoxy)caproate, remained. This corresponds to a yield of 98% of theory, based on the phenol employed. simultaneously in the course of 1 hour was distilled off After the addition The mixture was cooled to 90° C. 250 ml of water were added After separation of the phases washing with 200 ml of water, 347 g of a viscous yellow oil of the following composition (0.3% of ethyl bromocaproate, 0.5% of residual phenol and 98% of ethyl 2-(2,4-di-tert-butylphenoxy)caproate

Conditions: temp:140.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 206 g (1 mol) of 2,4-di-tert-butylphenol were melted and heated to 140° C. under nitrogen. 185 g (1.03 mol) of a 30% strength NaOMe solution in MeOH and 245 g (1.1 mol) of ethyl 2-bromocaproate were metered in simultaneously in the course of 1 hour. During the addition, a mixture of MeOH and EtOH was distilled off. After the addition, the reaction to give the ester mixture was complete. The mixture was cooled to 80° C., 20 g of NaOMe solution were added and 750 ml of ethanol were then added in the course of 4 hours. A methanol/ethanol mixture distilled off at an overhead temperature of initially 74° to 76° C. At the end, the temperature was increased to 90° C. and pure ethanol distilled over at 78° to 79° C. For isolation, 250 ml of water were added. After separation of the phases and renewed washing with 200 ml of water, 351 g of a viscous yellow oil of the following composition (0.3% of ethyl bromocaproate, 0.7 g of residual phenol, 98% of ethyl 2-(2,4-di-tert-butylphenoxy)caproate and 0.3% of methyl 2-(2,4-ditert-butylphenoxy)caproate, remained. This corresponds to a yield of 98.8% of theory, based on the phenol employed. simultaneously in the course of 1 hour During the addition was distilled off After the addition the reaction