Trifluoroacetic acid → 5,6-Dihydrophenanthridine

HRID 2181836Notes

Reaction equation

HRID 2181836 reaction equation
[CH2:1]([C:3]1[N:4]=[C:5]2[C:10](=[C:11]3[C:16]=1[CH:15]=[C:14]([F:17])[CH:13]=[CH:12]3)[CH:9]=[CH:8][CH:7]=[CH:6]2)[CH3:2].[BH4-].[Na+].FC(F)(F)C(O)=O.C1C=CC2C3C=CC=CC=3NCC=2C=1.C(N(CC)CC)C.[CH3:48][O:49][C:50]1[CH:55]=[CH:54][C:53]([S:56](Cl)(=[O:58])=[O:57])=[CH:52][C:51]=1[CH3:60]>O1CCCC1.ClCCl>[CH:14]1[CH:13]=[CH:12][C:11]2[C:10]3[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=3[NH:4][CH2:3][C:16]=2[CH:15]=1.[CH2:1]([CH:3]1[C:16]2[C:11](=[CH:12][CH:13]=[C:14]([F:17])[CH:15]=2)[C:10]2[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=2[N:4]1[S:56]([C:53]1[CH:54]=[CH:55][C:50]([O:49][CH3:48])=[C:51]([CH3:60])[CH:52]=1)(=[O:58])=[O:57])[CH3:2]

Participants

10

Procedure

The intermediate dihydrophenanthridine was prepared from 6-ethyl-8-fluoro-phenanthridine, (Example 40, Step b, 0.79 g, 3.48 mmol), by treatment with sodium borohydride (0.79 g, 21 mmol) and trifluoroacetic acid (1.1 mL, 14 mmol) in tetrahydrofuran (18 mL). In a separate, second step, the dihydrophenanthridine was treated with triethylamine (0.8 mL, 6 mmol) and 4-methoxy-3-methylbenzenesulfonyl chloride (0.66 g, 3.0 mmol, 2 equivalents) in dichloromethane (5 mL) according to the procedure and in the same manner as described in Example 32, Method A, Step d. The crude product was purified by flash column chromatography on silica gel, eluting with a mixture of ethyl acetate-hexane (1:19 to 3:7 gradient), to yield 6-ethyl-8-fluoro-5-[(4-methoxy-3-methylphenyl)sulfonyl]-5,6-dihydrophenanthridine as a homogeneous, white solid (0.57 g, 92% from the dihydrophenanthridine), m.p. 140° C.;

Workup

  1. customThe crude product was purified by flash column chromatography on silica gel
  2. washeluting with a mixture of ethyl acetate-hexane (1:19 to 3:7 gradient)

Sources & evidence

ORD record
ord-48ca3ab43e1a4464b8d6d3c21c51e4a1
Source dataset
uspto-grants-2005_05
Patent number
US06894061B2

Reaction notes

Loading…