Acetic Acid → 5,10-Dihydro-5-(4-amino-2-chlorobenzoyl)-4H-pyrazolo[5,1-c][1,4]benzodiazepine

HRID 1739919Notes

Reaction equation

[N+:1]([C:4]1[CH:25]=[CH:24][C:7]([C:8]([N:10]2[C:16]3[CH:17]=[CH:18][CH:19]=[CH:20][C:15]=3[CH2:14][N:13]3[N:21]=[CH:22][CH:23]=[C:12]3[CH2:11]2)=[O:9])=[C:6]([Cl:26])[CH:5]=1)([O-])=O.C([O-])(O)=O.[Na+].C(O)(=O)C>C(O)C>[NH2:1][C:4]1[CH:25]=[CH:24][C:7]([C:8]([N:10]2[C:16]3[CH:17]=[CH:18][CH:19]=[CH:20][C:15]=3[CH2:14][N:13]3[N:21]=[CH:22][CH:23]=[C:12]3[CH2:11]2)=[O:9])=[C:6]([Cl:26])[CH:5]=1

Participants

Conditions

Temperature: 75 °C

Procedure

A mixture of 0.553 g of 5,10-dihydro-5-(4-nitro-2-chlorobenzoyl)-4H-pyrazolo[5,1-c][1,4]benzodiazepine, 1.70 g of stannous chloride dihydrate in 20 ml of ethanol is heated at 70-80 ° C for 1 hour. The mixture is chilled, made basic with 1 M NaHCO3 and then stirred at room temperature for 0.5 hour. The mixture is brought to pH 5 with acetic acid and extracted (several times) with ethyl acetate. The combined extracts are dried (Na2SO4) and passed through a pad of hydrous magnesium silicate. The filtrate is evaporated and the residue dissolved in dichloromethane and the solution passed through a thin pad of hydrous magnesium silicate. The filtrate is evaporated in vacuo to give 0.40 g of a glass, m.p. 98-117° C.; Anal. Calc'd: C, 62.9; H, 4.7; N, 16.3; Cl, 11.6. Found: C, 62.4; H, 4.3; N, 15.6; Cl, 11.7.

Workup

temperatureThe mixture is chilled
extractionextracted (several times) with ethyl acetate
dry with materialThe combined extracts are dried (Na2SO4)
customThe filtrate is evaporated
dissolutionthe residue dissolved in dichloromethane
customThe filtrate is evaporated in vacuo

Sources & evidence

ORD record: ord-5f946829faa74f09b13fdb63a49d6252
Source dataset: uspto-grants-1999_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05968937

Reaction notes

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