2-bromo-5,5-dimethylcyclohexane-1,3-dione

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

Procedure: Bromine (0.51 mL, 10 mmol) was added dropwise to a solution of 5,5-dimethylcyclohexane-1,3-dione (1.4 g, 10 mmol) in AcOH (20 mL) at r.t. The reaction mixture was stirred for 2 h and then the product was isolated by filtration. The precipitate was washed with Et2O (2×100 mL) and then dried in vacuo give the title compound in quantitative yield as a light brown solid, which was used without further purification. LCMS (ES+) 218.9 (M+H)+. the product was isolated by filtration The precipitate was washed with Et2O (2×100 mL) dried in vacuo

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

Procedure: Bromine (0.51 mL, 10 mmol) was added dropwise to a solution of 5,5-dimethylcyclohexane-1,3-dione (1.4 g, 10 mmol) in AcOH (20 mL) at r.t. The reaction mixture was stirred for 2 h and then the product was isolated by filtration. The precipitate was washed with Et2O (2×100 mL) and then dried in vacuo give the title compound in quantitative yield as a light brown solid, which was used without further purification. LCMS (ES+) 218.9 (M+H)+. the product was isolated by filtration The precipitate was washed with Et2O (2×100 mL) dried in vacuo

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

Procedure: Bromine (0.51 mL, 10 mmol) was added dropwise to a solution of 5,5-dimethylcyclohexane-1,3-dione (1.4 g, 10 mmol) in AcOH (20 mL) at r.t. The reaction mixture was stirred for 2 h and then the product was isolated by filtration. The precipitate was washed with Et2O (2×100 mL) and then dried in vacuo give the title compound in quantitative yield as a light brown solid, which was used without further purification. LCMS (ES+) 218.9 (M+H)+. the product was isolated by filtration The precipitate was washed with Et2O (2×100 mL) dried in vacuo

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

Procedure: 82 g of 2-bromo-5,5-dimethylcyclohexane-1,3-dione, 40 g of sodium acetate and 50 g of N-methylthiourea are dissolved in 500 ml of acetic acid. The mixture is stirred at room temperature until the weakly exothermic reaction has subsided, and then refluxed for 3 hours. The reaction mixture is then concentrated to one third of its volume in a rotary evaporator, poured into 100 ml of water and cooled to 0° C. The precipitate is collected by filtration and dried in vacuo at 80° C., affording 64 g of 2-methylamino-5,5-dimethyl-7-oxo-4,5-dihydro-6H-benzthiazole with a melting point of 217°-218° C. refluxed for 3 hours The reaction mixture is then concentrated to one third of its volume in a rotary evaporator poured into 100 ml of water cooled to 0° C The precipitate is collected by filtration dried in vacuo at 80° C.

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

Procedure: 28 g of 2-bromo-5,5-dimethylcyclohexane-1,3-dione and 11.7 g of thiourea are dissolved in 200 ml of ethanol. After the weakly exothermic reaction has subsided, the mixture is refluxed for a further 6 hours. The solution is diluted with 400 ml of water and neutralised with saturated sodium bicarbonate solution. The precipitated crystals are collected by filtration and dried in vacuo at 80° C., affording 21 g of 2-amino-5,5-dimethyl-7-oxo-4,5-dihydro-6H-benzthiazole with a melting point of 203°-205° C. After the weakly exothermic reaction the mixture is refluxed for a further 6 hours The precipitated crystals are collected by filtration dried in vacuo at 80° C.

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

Procedure: To a stirred solution of 5,5-dimethylcyclohexane-1,3-dione (1.4 g, 10 mmol) in AcOH (20 mL) at r.t. was added bromine (1.6 g, 0.51 mL, 10 mmol) dropwise. The reaction was carried out according to Method A to give the title compound in quantitative yield as a light brown solid, which was used without further purification. LCMS (ES+) 218.9 (M+H)+.

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

Procedure: Bromine (0.51 mL, 10 mmol) was added dropwise to a solution of 5,5-dimethylcyclohexane-1,3-dione (1.4 g, 10 mmol) in AcOH (20 mL) at r.t. The reaction mixture was stirred for 2 h and then the product was isolated by filtration. The precipitate was washed with Et2O (2×100 mL) and then dried in vacuo give the title compound in quantitative yield as a light brown solid, which was used without further purification. LCMS (ES+) 218.9 (M+H)+. the product was isolated by filtration The precipitate was washed with Et2O (2×100 mL) dried in vacuo