Sulfuric Acid → N-(4,4'-Dihydroxybenzhydrylidene)-N'-(3-nitrophenyl)hydrazine

HRID 1879620Notes

Reaction equation

[OH:1][C:2]1[CH:16]=[CH:15][C:5]([C:6]([C:8]2[CH:13]=[CH:12][C:11]([OH:14])=[CH:10][CH:9]=2)=O)=[CH:4][CH:3]=1.Cl.[N+:18]([C:21]1[CH:22]=[C:23]([NH:27][NH2:28])[CH:24]=[CH:25][CH:26]=1)([O-:20])=[O:19].S(=O)(=O)(O)O>CO>[OH:1][C:2]1[CH:16]=[CH:15][C:5]([C:6](=[N:28][NH:27][C:23]2[CH:24]=[CH:25][CH:26]=[C:21]([N+:18]([O-:20])=[O:19])[CH:22]=2)[C:8]2[CH:13]=[CH:12][C:11]([OH:14])=[CH:10][CH:9]=2)=[CH:4][CH:3]=1

Participants

Conditions

Temperature: 50 °C

Procedure

A solution of 4,4′-dihydroxybenzophenone (0.32 g, 1.5 mmol) in 10 mL of methanol was added to a solution of 3-nitrophenylhydrazine hydrochloride (0.43 g, 2.25 mmol), concentrated sulfuric acid (0.3 mL) in 10 mL of methanol at 50° C. It was stirred at 50° C. for additional 2 h. The reaction mixture was concentrated and diluted with 20 mL of water. The precipitates were separated by filtration and washed with 3% aqueous NaHCO3 and water. The crude product was recrystallized from ethanol to give 0.4 g (77% yield) of the desired compound as a yellow solid, mp 160-162° C. 1H NMR (300 MHz, d6-DMSO): δ6.71 [d, 2H, J=8.8 Hz, Ar—H], 6.91 [d, 2H, J=8.1 Hz, Ar—H], 7.07 [d, 2H, J=8.8 Hz, Ar—H], 7.27 [d, 2H, J=8.8 Hz, Ar—H], 7.40 [dd, 1H, J=J2=8.1 Hz, Ar—H], 7.49 [d, 1H, J=8.1 Hz, Ar—H], 7.61 (dd, 1H, J1=8.4 Hz, J2=2.2 Hz, Ar—H], 7.99 [d, 1H, J=2.2 Hz, Ar—H], 9.25 [s, 1H, NH], 9.78 and 9.62 [s, 1H, OH].

Workup

concentrationThe reaction mixture was concentrated
additiondiluted with 20 mL of water
customThe precipitates were separated by filtration
washwashed with 3% aqueous NaHCO3 and water
customThe crude product was recrystallized from ethanol

Sources & evidence

ORD record: ord-e102cb869c4441eb8127dc5eb1d9e238
Source dataset: uspto-grants-2012_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08318699B2

Reaction notes

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