Dimethylformamide → HCID 22605378, compound

Participants

Reaction Steps

By employing thallium chemistry, the 4-iodo-5-methoxy-indole-3-carboxaldehyde was prepared according to the procedure of Moody, C. J.; Swann, E. J. Chem. Soc. Perkin I 1993, 21, 2561 and the 5-chloro-4-iodo-indole-3-carboxaldehyde according to the procedure of Ohta, T.; Yamato, Y.; Tahira, H.; Somei M., Heterocycles 1987, 11, 2817 (and references therein). These derivatives were subsequently reacted with NaH and iodomethane in DMF to provide the corresponding N-methyl derivatives, which were then used for the preparation of compounds 190, 280 and 212 following a procedure analogous to that described in example 1. Following the general procedure of Ohta, T.; Yamato, Y.; Tahira, H.; Somei M., Heterocycles 1987, 11, 2817 (and references therein), as used above for the preparation of the 5-chloro-4-iodo-indole-3-carboxaldehyde, the 4-halogenated derivatives for a number of commercially available 5 or 6 substituted indole-3-carboxyladehydes were prepared via thallium-mediated chemistry, using (i) reaction with thallium tris-trifluoro acetate, followed by (ii) reaction an electrophile, such as KI or CuBr2. The resulting 4,5− or 4,6− disubstituted indole-3-carboxaldehydes were subsequently methylated at the indole N-position, as described in examples 13 and 16. The products were used for condensation with appropriate pyrazolones as described in example 1, to provide the desired compounds. Compounds 203, 266, 267, 281, 214, 221, 220, 222, 223, 289, 218, 219, 225, 226, 227, 228, 229, and 230 were derived following the sequence of steps described above.

Provenance & Evidence