Reaction equation
[N+:1]([C:4]1[CH:5]=[CH:6][CH:7]=[C:8](N)[C:9]=1[C:10](O)=O)([O-:3])=[O:2].[CH3:14][C:15]([CH3:21])=[C:16]1C=[CH:19][CH:18]=[CH:17]1.C(ON=O)(C)(C)C>C(COC)OC>[C:15](=[C:16]1[CH:10]2[C:9]3[C:8]([CH:17]1[CH:18]=[CH:19]2)=[CH:7][CH:6]=[CH:5][C:4]=3[N+:1]([O-:3])=[O:2])([CH3:21])[CH3:14]Participants
Procedure
A solution containing 6-nitroanthranilic acid (3) (19.65 g, 0.108 mol) and commercially available 6,6-dimethylfulvene (4) (17.2 g, 0.162 mol) in dimethoxyethane (DME, 125 mL) was added dropwise over 50 min to a stirred, 70° C. solution of tert-butylnitrite (90%, 17.3 g, 0.151 mol) in DME (350 mL). The mixture was stirred for 1 h and was cooled to room temperature. The reaction mixture was evaporated to yield a crude thick black oil which was directly subjected to silica gel chromatography eluting with ethyl acetate in petroleum ether (0-5% gradient) to afford 10 g of the crude product as a yellow oil, which partially crystallized on standing. Recrystallization from heptane gave the title compound (6.5 g, 26.5%) as a pale yellow solid: 1H NMR (300 MHz, DMSO) δ 7.70 (d, 1H), 7.42 (d, 1H), 7.09-7.01 (m, 1H), 7.00-6.92 (m, 2H), 5.33 (bs, 1H), 4.45 (bs, 1H), 1.55 (s, 6H); EIMS m/z 227.
Workup
- customThe reaction mixture was evaporated
- customto yield a crude thick black oil which
- washeluting with ethyl acetate in petroleum ether (0-5% gradient)
- customto afford 10 g of the crude product as a yellow oil, which
- custompartially crystallized
- customRecrystallization from heptane
Sources & evidence
- ORD record
- ord-c7815308d0f94cfba47ff09947194d25
- Source dataset
- uspto-grants-2014_10
- Patent number
- US08859558B2
Linked notes
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