1-Nitro-9H-fluoren-9-one synthesis

13synthesis methods

Product Name:1-Nitro-9H-fluoren-9-one
CAS Number:56825-82-2
Molecular formula:C13H7NO3
Molecular Weight:225.2

[1,1'-Biphenyl]-2-carboxylic acid, 3-nitro-

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56825-82-2
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Yield:56825-82-2 87%

Reaction Conditions:

with sulfuric acid at 100 - 110;Friedel-Crafts Acylation;

Steps:

1-Nitro-9H-fluoren-9-one (4a)⁷

3-Nitrobiphenyl-2-carboxylic acid (3a, 1.95 g, 8.0 mmol) was dissolved in sulfuric acid (98%, 6 mL) at room temperature. The brown solution was stirred for 10 minutes at 100 - 110 °C. The resulting black reaction mixture was cooled and poured on ice (25 g.). A gray-green precipitate was formed and S1-3 filtered off. It was washed with aqueous NaHCO₃ (5%, 3 mL), H₂O (6 x 3 mL), and dried at 60°C. The raw product (1.63 g) was dissolved in CHCl₃ (120 mL), filtered through a plug of silica gel. The solvent was evaporated and the residue was recrystallized from MeCN (20 mL) to give the title compound 4a (1.58 g, 7.0 mmol, 87% yield, R_f = 0.2, cyclohexane/CHCl₃, 1:3) as yellow rods. ¹H NMR (400 MHz, CDCl₃) δ_H 7.75 (d, J = 7.4 Hz, 1H_Ar, 4-H), 7.70 (d, J = 7.4 Hz, 1H_Ar, 2-H), 7.63 (t, J= 7.8 Hz, 1H_Ar, 3-H), 7.60 - 7.52 (m, 3H_Ar, 5-H, 6-H, 8-H), 7.38 (td, J = 7.3, 1.5 Hz, 1H_Ar, 7-H). ¹³C NMR (101 MHz, CDCl₃) δ_C 187.59 (1C, C=O), 146.42 (1C_Ar, 1-C), 142.28 (1C_Ar, 5a-C), 135.68(1C_ArH, 6-C), 135.41 (2C: 1C_Ar, 4a-C, 1C_ArH, 3-C), 133.49 (1C_Ar, 8a-C), 130.63 (1C_ArH, 7-C), 125.40(1C_ArH, 8-C), 125.10 (1C_Ar, 9a-C), 123.77 (1C_ArH, 4-C), 123.25 (1C_ArH, 2-C), 120.91 (1C_ArH, 5-C).

References:

Teodoro, Rodrigo;Scheunemann, Matthias;Wenzel, Barbara;Peters, Dan;Deuther-Conrad, Winnie;Brust, Peter [Bioorganic and Medicinal Chemistry Letters,2018,vol. 28,# 9,p. 1471 - 1475] Location in patent:supporting information