2-Phenylindole synthesis

14synthesis methods

Product Name:2-Phenylindole
CAS Number:948-65-2
Molecular formula:C14H11N
Molecular Weight:193.24

2-phenylindole is prepared by condensing phenylhydrazine and acetophenone, and then closing the ring in the presence of zinc chloride. or it can be prepared by heating bromoacetophenone with excess aniline, or heating N-(2-methylphenyl)benzamide and sodium ethoxide at 360-380℃ in isolation from air.

98-86-2 Synthesis

98-86-2
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$9.00/5g

100-63-0 Synthesis

100-63-0
373 suppliers
$10.00/1g

948-65-2
298 suppliers
$5.00/10g

Yield:948-65-2 86%

Reaction Conditions:

with acetic acid;zinc(II) chloride in neat (no solvent) at 25 - 180; for 0.416667 h;Fischer Indole Synthesis;Reagent/catalyst;

Steps:

General procedure for the synthesis of 2-phenylindole (4a)
General procedure: Phenylhydrazine 1a (5.1 mmol) and acetophenone 2a (5 mmol) and anhydrous zinc chloride (200 mol %) were mixed together using pestle in mortar and few drops ofacetic acid (0.1 N) was added drop-wise with continuous mixing at room temperature for 10 min. The mixture was transferred into a round-bottomed flask fitted with a reflux condenser attached with CaCl₂ guard tube. Then the mixture was heated slowly up to the temperature of 180 °C. The reaction was monitored by TLC using 10% ethyl acetatein n-hexane and the reaction was observed to be completed within 15 min. The mixture was cooled to room temperature and diluted with 5mL dichloromethane and 5mL water. The dichloromethane layer was separated and aqueous layer extracted repeatedly with dichloromethane (3 x 5mL). The combined organic layer was dried over anhydrous Na₂SO₄, filtered, and solvent was evaporated under reduced pressure. The crude product was purified using flash column chromatography over silica gel using 6% ethyl acetate in hexane as eluent to afford the pure product 2-phenylindole 4a in 86% yield as light yellow solid (Table 1, entry 1). MP 194 °C; ¹H-NMR (500 MHz, CDCl₃) : 8.33 (brs, 1H), 7.67-7.65 (m, 3H), 7.46-7.39 (m, 3H), 7.35-7.13 (m, 3H), 6.84 (s, 1H); ¹³CNMR (125 MHz, CDCl₃) 137.99, 136.91, 132.45, 129.35, 129.14, 127.83, 125.27, 122.47, 120.79, 120.49, 111.03, 100.08; IR (ν_max: 3428.01, 3053.42, 1524.95, 1345.96, 1181.15, 739.99, 685.12 cm^-1): HRMS (EI+): m/z calculated for C₁₄H₁₁N [M+H]⁺: 194.0970, found 194.0964.

References:

Gaikwad, Ruchi;Bobde, Yamini;Ganesh, Routholla;Patel, Tarun;Rathore, Anju;Ghosh, Balaram;Das, Kalpataru;Gayen, Shovanlal [Synthetic Communications,2019,vol. 49,# 17,p. 2258 - 2269]

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