C(OC([C:6]1[C:10]([C:11]2[CH:16]=[CH:15][C:14]([I:17])=[CH:13][CH:12]=2)=[CH:9][NH:8][CH:7]=1)=O)C.[OH-].[Na+].[Na+].[Cl-]>C(O)CO>[I:17][C:14]1[CH:13]=[CH:12][C:11]([C:10]2[CH:6]=[CH:7][NH:8][CH:9]=2)=[CH:16][CH:15]=1Following earlier procedures (Balasubramanian, T.; Lindsey, J. S. Tetrahedron 1999, 55, 6771-6784), a mixture of 3-ethoxycarbonyl-4-(4-iodophenyl)pyrrole (7.20 g, 21.1 mmol) and ethylene glycol (55 mL) in a 100-mL Claisen flask was flushed with argon for 10 min and powdered NaOH (2.2 g, 55 mmol) was then added. The flask was placed in an oil bath at 120° C. and the oil bath temperature was raised to 160° C. After 2.5 h, the flask was cooled to room temperature and treated with 10% aq NaCl (100 mL). The aqueous layer was extracted with CH2Cl2, the organic layers were collected, washed with 10% aq NaCl, dried (Na2SO4), concentrated, and recrystallized in ethanol affording light brown crystals (5.18 g, 91%). mp 164-165° C.; 1H NMR δ 6.51 (m, 1H), 6.83 (m, 1H), 7.08 (s, 1H), 7.27 (d, J=8.7 Hz, 2H), 7.63 (d, J=8.7 Hz, 2H); 13C NMR δ89.9, 106.3, 114.7, 119.1, 123.8, 127.0, 135.2, 137.5; EI-MS obsd 268.9702, calcd 268.9702. Anal. Calcd for C10H8IN: C, 44.6; H, 3.0; N, 5.2. Found: C, 44.7; H, 3.0; N, 5.1. The synthesis starting from 4-iodobenzaldehyde (35 g), monoethyl malonate, and TosMIC has been performed with linear scale up of the established procedures, affording 21.5 g of 4.
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