1-Isopropylhydrazine hydrochloride → 8-bromo-2-(2-isopropyl-2H-[1,2,4]triazol-3-yl)-4,5-dihydro-6-oxa-1,3a-diaza-benzo[e]azulene

Participants

Reaction Conditions

Reaction Steps

Alternatively, to a suspension of 8-bromo-4,5-dihydro-6-oxa-1,3a-diaza-benzo[e]azulene-2-carboxylic acid 1-dimethylamino-meth-(Z)-ylideneamide (8.52 g, 23.5 mmol) in acetic acid (50 mL) was added isopropylhydrazine hydrochloride (3.37 g, 30.5 mmol) and the reaction mixture heated at 100° C. for 1 h. The reaction mixture was allowed to cool to RT and was poured onto water (500 mL) causing the product to precipitate as an off-white solid. The product was collected by filtration, washed with water (˜200 mL) and dried in vacuo at 45° C. for 16 h to yield 194 as an off-white solid (7.88 g, 86%). 1H NMR (400 MHz, d6-DMSO) 8.43 (1H, d, J=8.6 Hz), 7.97 (1H, s), 7.92 (1H, d, J=0.6 Hz), 7.36 (1H, dd, J=8.6, 2.0 Hz), 7.30 (1H, d, J=2.0 Hz), 5.86 (1H, sept, J=6.6 Hz), 4.56-4.52 (4H, m), 1.48 (6H, d, J=6.6 Hz). LCMS: RT=4.69 min, M+H+=374/376. 1H NMR showed product to contain ˜5% 8-iodo-2-(2-isopropyl-2H-[1,2,4]triazol-3-yl)-4,5-dihydro-6-oxa-1,3a-diaza-benzo[e]azulene.

Provenance & Evidence