Methane → 3-Amino-5-(4-benzyl-1-piperazinyl)-4-pyrazolecarbonitrile

HRID 482870Notes

Reaction equation

CS[C:3](=[C:6]([C:9]#[N:10])[C:7]#[N:8])SC.[CH2:11]([N:18]1[CH2:23][CH2:22][NH:21][CH2:20][CH2:19]1)[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1.CS.O.[NH2:27][NH2:28].C>C(#N)C>[NH2:8][C:7]1[C:6]([C:9]#[N:10])=[C:3]([N:21]2[CH2:22][CH2:23][N:18]([CH2:11][C:12]3[CH:13]=[CH:14][CH:15]=[CH:16][CH:17]=3)[CH2:19][CH2:20]2)[NH:28][N:27]=1

Participants

Conditions

Temperature: -10 °C

Procedure

A mixture of 4.25 g (0.025 moles) of [bis(methylthio)methylene]malononitrile [K. A. Jensen and L. Hendriksen, Acta Chem. Scand., 22(4), 1107 (1968)] and 4.7 g (0.025 moles) of 1-benzylpiperazine in 100 ml of acetonitrile was stirred at reflux for 5 hours with evolution of methanethiol. Then 1.31 g (0.025 moles) of hydrazine hydrate was added and the solution was stirred at reflux for 16 hours, again with evolution of methanethiol. The reaction mixture was clarified while hot with activated charcoal and filtered through diatomaceous earth. The filtrate was cooled at -10° C. and a white precipitate developed. The precipitate was collected by filtration, washed with 50 ml of cold acetonitrile, air dried, then dried in vacuo at 60° C. and gave 4.5 g of crude product. The material was recrystallized from 150 ml of 2-propanol, cooled at -10° C. and gave 2.8 g of the desired product as a white solid, mp 157°-158° C.

Workup

filtrationfiltered through diatomaceous earth
filtrationThe precipitate was collected by filtration
washwashed with 50 ml of cold acetonitrile, air
customdried
customdried in vacuo at 60° C.
customgave 4.5 g of crude product
customThe material was recrystallized from 150 ml of 2-propanol
temperaturecooled at -10° C.

Sources & evidence

ORD record: ord-4f309fa05cbb47309170a5e01c048a9c
Source dataset: uspto-grants-1986_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04576943

Reaction notes

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