(4-bromophenyl)thiourea

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

Procedure: A solution of N-(4-bromophenyl)thiourea (16.18 g) and magnesium oxide (1.41 g) in chlorobenzene (100 mL) was heated to 50° C., and a solution of sulfuryl chloride (8.43 mL) in chlorobenzene (9 mL) was added dropwise to the solution over 1 hour or longer, followed by stirring at 50° C. overnight. The reaction mixture was returned to room temperature, and water (20 mL) was added thereto. The pH of the mixture was adjusted to about 8 by use of concentrated aqueous ammonia, and the precipitates were recovered through filtration. The obtained solid was recrystallized from 90% ethanol, to thereby yield the title compound (7.95 g). was returned to room temperature the precipitates were recovered through filtration The obtained solid was recrystallized from 90% ethanol

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

Procedure: 4-Bromophenylisothiocyanate (21.4 g) was dissolved in tetrahydrofuran (50 mL), and concentrated aqueous ammonia (28%) (13.7 mL) was added dropwise to the solution, followed by stirring at room temperature for 10 minutes. The solvent was concentrated under reduced pressure, and the crystals were recovered through filtration by use of water, followed by recrystallization from ethanol, to thereby yield the title compound (16.4 g). The solvent was concentrated under reduced pressure the crystals were recovered through filtration by use of water followed by recrystallization from ethanol

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

Procedure: 4-Bromophenylisothiocyanate (21.4 g) was dissolved in tetrahydrofuran (50 mL), and concentrated aqueous ammonia (28%) (13.7 mL) was added dropwise to the solution, followed by stirring at room temperature for 10 minutes. The solvent was concentrated under reduced pressure, and the crystals were recovered through filtration by use of water, followed by recrystallization from ethanol, to thereby yield the title compound (16.4 g). The solvent was concentrated under reduced pressure the crystals were recovered through filtration by use of water followed by recrystallization from ethanol

Conditions: temp:65.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A suspension of N-(6-bromo-7-oxo-4,5,6,7-tetrahydro-1,3-benzothiazol-2-yl)-N′-ethylurea (50 mg, 0.16 mmol) and 4-bromo-phenyl-thiourea (36 mg, 0.16 mmol) in THF (1.0 mL) was heated to about 65° C. for about 1.5 hrs. The reaction mixture was pumped down and used in the next step without further purification. used in the next step without further purification

Conditions: temp:65.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A suspension of N-(6-bromo-7-oxo-4,5,6,7-tetrahydro-1,3-benzothiazol-2-yl)-N′-ethylurea (50 mg, 0.16 mmol) and 4-bromo-phenyl-thiourea (36 mg, 0.16 mmol) in THF (1.0 mL) was heated to about 65° C. for about 1.5 hrs. The reaction mixture was pumped down and used in the next step without further purification. used in the next step without further purification

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

Procedure: 190 Parts of sulfuryl chloride were added homogeneously within 4 hours at a temperature of 45°-50° C. with stirring to 231 parts of 4-bromophenylthiourea suspended in 1,200 parts of o-dichlorobenzene. After the gas development had ceased, the batch was cooled to about 20° C., the curde 2-amino-6-bromobenzothiazolium chloride precipitated was suction-filtered and washed with o-dichlorobenzene. The filter cake moist with the solvent was suspended in 1,000 parts of water, the adhering o-dichlorobenzene was distilled off by blowing in steam, and the solution of 2-amino-6-bromobenzothiazolium chloride obtained was filtered off from the greasy undissolved matter after having added 10 parts of active charcoal at 95° C. The clear filtrate was adjusted to pH 8 with 25% sodium hydroxide solution, which caused the free 2-amino-6-bromobenzothiazole to precipitate as yellowish, slightly tacky matter. After cooling, the solids having become vitreous were isolated and dried in vacuo at 40°-50° C. 167 Parts of 2-amino-6-bromobenzothiazole having a purity degree of 88% were obtained (=147.1 parts of 100% compound, 64.2% of th.). By repeated redissolution in dilute hydrochloric acid with addition of active charcoal, 2-amino-6-bromobenzothiazole having a purity degree of >95% was obtained. However, this purification was very expensive and caused great losses, so that at best 82 parts of the intended compound were obtained (35.8% of th., relative to 4-bromophenylthiourea used). was obtained However, this purification

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 190 Parts of sulfuryl chloride were added homogeneously within 4 hours at a temperature of 45°-50° C. with stirring to 231 parts of 4-bromophenylthiourea suspended in 1,200 parts of o-dichlorobenzene. After the gas development had ceased, the batch was cooled to about 20° C., the curde 2-amino-6-bromobenzothiazolium chloride precipitated was suction-filtered and washed with o-dichlorobenzene. The filter cake moist with the solvent was suspended in 1,000 parts of water, the adhering o-dichlorobenzene was distilled off by blowing in steam, and the solution of 2-amino-6-bromobenzothiazolium chloride obtained was filtered off from the greasy undissolved matter after having added 10 parts of active charcoal at 95° C. The clear filtrate was adjusted to pH 8 with 25% sodium hydroxide solution, which caused the free 2-amino-6-bromobenzothiazole to precipitate as yellowish, slightly tacky matter. After cooling, the solids having become vitreous were isolated and dried in vacuo at 40°-50° C. 167 Parts of 2-amino-6-bromobenzothiazole having a purity degree of 88% were obtained (=147.1 parts of 100% compound, 64.2% of th.). By repeated redissolution in dilute hydrochloric acid with addition of active charcoal, 2-amino-6-bromobenzothiazole having a purity degree of >95% was obtained. However, this purification was very expensive and caused great losses, so that at best 82 parts of the intended compound were obtained (35.8% of th., relative to 4-bromophenylthiourea used). the curde 2-amino-6-bromobenzothiazolium chloride precipitated was suction-filtered washed with o-dichlorobenzene the adhering o-dichlorobenzene was distilled off

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

Procedure: A solution of N-(4-bromophenyl)thiourea (16.18 g) and magnesium oxide (1.41 g) in chlorobenzene (100 mL) was heated to 50° C., and a solution of sulfuryl chloride (8.43 mL) in chlorobenzene (9 mL) was added dropwise to the solution over 1 hour or longer, followed by stirring at 50° C. overnight. The reaction mixture was returned to room temperature, and water (20 mL) was added thereto. The pH of the mixture was adjusted to about 8 by use of concentrated aqueous ammonia, and the precipitates were recovered through filtration. The obtained solid was recrystallized from 90% ethanol, to thereby yield the title compound (7.95 g). was returned to room temperature the precipitates were recovered through filtration The obtained solid was recrystallized from 90% ethanol

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

Procedure: 4-Bromophenylisothiocyanate (21.4 g) was dissolved in tetrahydrofuran (50 mL), and concentrated aqueous ammonia (28%) (13.7 mL) was added dropwise to the solution, followed by stirring at room temperature for 10 minutes. The solvent was concentrated under reduced pressure, and the crystals were recovered through filtration by use of water, followed by recrystallization from ethanol, to thereby yield the title compound (16.4 g). The solvent was concentrated under reduced pressure the crystals were recovered through filtration by use of water followed by recrystallization from ethanol

Conditions: temp:65.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A suspension of N-(6-bromo-7-oxo-4,5,6,7-tetrahydro-1,3-benzothiazol-2-yl)-N′-ethylurea (50 mg, 0.16 mmol) and 4-bromo-phenyl-thiourea (36 mg, 0.16 mmol) in THF (1.0 mL) was heated to about 65° C. for about 1.5 hrs. The reaction mixture was pumped down and used in the next step without further purification. used in the next step without further purification