HCID 86700137, compound → HCID 86700138, compound

Participants

Reaction Conditions

Reaction Steps

Polyphosphoric acid (PPA) (140 g) and THF (210 mL) were heated to 75° C. in a 1 L recovery flask. (E)-ethyl 2-(2-bromo-7-(4-chlorophenyl)-7-hydroxy-5-methyl-4,5-dihydrobenzo[d]thiazol-6(7H)-ylidene)acetate (31.0 g, 70.0 mmol) was added via addition funnel in THF (70 mL) over 2 min. The funnel was rinsed with THF (20 mL). The reaction mixture was heated at 80° C. for 2.5 h. After cooling to rt, the mixture was poured onto a 1 M K2HPO4 (1.5 L) solution followed by EtOAc (700 mL). The layers were separated, and the organic layer was washed with brine (500 mL). The organic layer was dried, filtered, and concentrated in vacuo to give desired product that was used without further purification. 1H NMR (400 MHz, CDCl3): δ 7.81 (s, 1H), 7.45 (d, 2H, J=8 Hz), 7.29 (d, 2H, J=8 Hz), 4.13 (q, 2H, J=7 Hz), 3.57 (s, 2H), 2.45 (s, 3H), 1.23 (t, 3H, J=7 Hz).

Provenance & Evidence