1-amino-3-cyclopentylthiourea

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

Procedure: A stirred slurry of 8.3 g (0.052 mole) of 4-cyclopentyl-3-thiosemicarbazide in 50 mL of absolute ethanol under nitrogen atmosphere was treated with 8.6 g (0.052 mole) of ethyl 2-chloroacetoacetate. The reaction mixture which, after filtering, turned pale yellow, as stirred for 18 hr at ambient temperature, treated with 20 mL of 2N ethanolic hydrogen chloride and heated at reflux for 1 hr. The reaction mixture was filtered hot and the filtrate concentrated in vacuo to a yellow-orange solid. Most of the solid was dissolved in 100 mL of hot absolute ethanol. The mixture was filtered, and when the filtrate was treated with dipropyl ether (150 mL) a precipitate formed which was collected by filtration to give 11.7 g of crude product. Recrystallization from benzene/ligroin with charcoal treatment gave 7.6 g of fine white fluffy needles, mp 175°-177° C. The reaction mixture which, after filtering treated with 20 mL of 2N ethanolic hydrogen chloride heated at reflux for 1 hr The reaction mixture was filtered hot the filtrate concentrated in vacuo to a yellow-orange solid Most of the solid was dissolved in 100 mL of hot absolute ethanol The mixture was filtered when the filtrate was treated with dipropyl ether (150 mL) a precipitate formed which was collected by filtration to give 11.7 g of crude product Recrystallization from benzene/ligroin with charcoal treatment

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

Procedure: A stirred slurry of 8.3 g (0.052 mole) of 4-cyclopentyl-3-thiosemicarbazide in 50 mL of absolute ethanol under nitrogen atmosphere was treated with 8.6 g (0.052 mole) of ethyl 2-chloroacetoacetate. The reaction mixture which, after filtering, turned pale yellow, as stirred for 18 hr at ambient temperature, treated with 20 mL of 2N ethanolic hydrogen chloride and heated at reflux for 1 hr. The reaction mixture was filtered hot and the filtrate concentrated in vacuo to a yellow-orange solid. Most of the solid was dissolved in 100 mL of hot absolute ethanol. The mixture was filtered, and when the filtrate was treated with dipropyl ether (150 mL) a precipitate formed which was collected by filtration to give 11.7 g of crude product. Recrystallization from benzene/ligroin with charcoal treatment gave 7.6 g of fine white fluffy needles, mp 175°-177° C. The reaction mixture which, after filtering treated with 20 mL of 2N ethanolic hydrogen chloride heated at reflux for 1 hr The reaction mixture was filtered hot the filtrate concentrated in vacuo to a yellow-orange solid Most of the solid was dissolved in 100 mL of hot absolute ethanol The mixture was filtered when the filtrate was treated with dipropyl ether (150 mL) a precipitate formed which was collected by filtration to give 11.7 g of crude product Recrystallization from benzene/ligroin with charcoal treatment

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

Procedure: A stirred slurry of 8.3 g (0.052 mole) of 4-cyclopentyl-3-thiosemicarbazide in 50 mL of absolute ethanol under nitrogen atmosphere was treated with 8.6 g (0.052 mole) of ethyl 2-chloroacetoacetate. The reaction mixture which, after filtering, turned pale yellow, as stirred for 18 hr at ambient temperature, treated with 20 mL of 2N ethanolic hydrogen chloride and heated at reflux for 1 hr. The reaction mixture was filtered hot and the filtrate concentrated in vacuo to a yellow-orange solid. Most of the solid was dissolved in 100 mL of hot absolute ethanol. The mixture was filtered, and when the filtrate was treated with dipropyl ether (150 mL) a precipitate formed which was collected by filtration to give 11.7 g of crude product. Recrystallization from benzene/ligroin with charcoal treatment gave 7.6 g of fine white fluffy needles, mp 175°-177° C. The reaction mixture which, after filtering treated with 20 mL of 2N ethanolic hydrogen chloride heated at reflux for 1 hr The reaction mixture was filtered hot the filtrate concentrated in vacuo to a yellow-orange solid Most of the solid was dissolved in 100 mL of hot absolute ethanol The mixture was filtered when the filtrate was treated with dipropyl ether (150 mL) a precipitate formed which was collected by filtration to give 11.7 g of crude product Recrystallization from benzene/ligroin with charcoal treatment

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

Procedure: A stirred slurry of 8.3 g (0.052 mole) of 4-cyclopentyl-3-thiosemicarbazide in 50 mL of absolute ethanol under nitrogen atmosphere was treated with 8.6 g (0.052 mole) of ethyl 2-chloroacetoacetate. The reaction mixture which, after filtering, turned pale yellow, was stirred for 18 hr at ambient temperature, treated with 20 mL of 2N ethanolic hydrogen chloride and heated at reflux for 1 hr. The reaction mixture was filtered hot and the filtrate concentrated in vacuo to a yellow-orange solid. Most of the solid was dissolved in 100 mL of hot absolute ethanol. The mixture was filtered, and when the filtrate was treated with dipropyl ether (150 mL) a precipitate formed which was collected by filtration to give 11.7 g of crude product. Recrystallization from benzene/ligroin with charcoal treatment gave 7.6 g of fine white fluffy needles, mp 175°-177° C. The reaction mixture which, after filtering treated with 20 mL of 2N ethanolic hydrogen chloride heated at reflux for 1 hr The reaction mixture was filtered hot the filtrate concentrated in vacuo to a yellow-orange solid Most of the solid was dissolved in 100 mL of hot absolute ethanol The mixture was filtered when the filtrate was treated with dipropyl ether (150 mL) a precipitate formed which was collected by filtration to give 11.7 g of crude product Recrystallization from benzene/ligroin with charcoal treatment