Methanesulfonic Acid → 7-Chloro-1-(2,4-difluorophenyl)-6-fluoro-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid

HRID 1953072Notes

Reaction equation

O1CCCC1.CS(O)(=O)=O.[Cl:11][C:12]1[N:21]=[C:20]2[C:15]([C:16](=[O:35])[C:17]([C:30]([O:32]CC)=[O:31])=[CH:18][N:19]2[C:22]2[CH:27]=[CH:26][C:25]([F:28])=[CH:24][C:23]=2[F:29])=[CH:14][C:13]=1[F:36]>O>[Cl:11][C:12]1[N:21]=[C:20]2[C:15]([C:16](=[O:35])[C:17]([C:30]([OH:32])=[O:31])=[CH:18][N:19]2[C:22]2[CH:27]=[CH:26][C:25]([F:28])=[CH:24][C:23]=2[F:29])=[CH:14][C:13]=1[F:36]

Participants

Conditions

Temperature: 25 °C

Procedure

A mixture of tetrahydrofuran (450 cm3), water (50 cm3), methanesulfonic acid (127 cm3) and ethyl 7-chloro-1-(2,4-difluorophenyl)-6-fluoro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylate (United Kingdom Patent Publication No. GB 2,191,776) was heated at reflux for 1 hour, and then cooled to 25° C. The resulting crystals were isolated, washed with tetrahydrofuran, and dried under vacuum to afford 41.3 g (89%) of the above-titled compound: m.p.=250° C.; (Found: C, 50.4; H, 1.7; Cl, 9.9; F, 16.0; N, 8.0. C15H6ClF3N2O3 requires C, 50.8; H, 1.7; Cl, 10.0; F, 16.1; N, 7.9%); 1H NMR (300 MHz, d6 -DMSO) δ 13.9 (s, 1H), 9.09 (s, 1H), 8.77 (d, J=7.5 Hz, 1H), 7.86 (td, J=5.9 and 8.8 Hz, 1H), 7.66 (ddd, J=2.7, 9.0 and 11.8 Hz, 1H), 7.39 (tm, J=8.6 Hz, 1H), 7.39 (tm, J=8.6 Hz, 1H); νmax (DRIFTS) cm-1 3130, 3060, 2947, 2885, 2821, 2723, 2637, 2594, 1734, 1641, 1623, 1579, 1544, 1516.

Workup

temperaturewas heated
temperatureat reflux for 1 hour
customThe resulting crystals were isolated
washwashed with tetrahydrofuran
customdried under vacuum

Sources & evidence

ORD record: ord-3c23db7804b84ecdb770e4a2ff0b21c6
Source dataset: uspto-grants-2000_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06114531

Reaction notes

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