Trifluoroacetic anhydride → 1,3-Diethyl-8-methoxy-7-nitro-1,3,4,5-tetrahydro-benzo[d]azepin-2-one

HRID 1040665Notes

Reaction equation

[CH2:1]([CH:3]1[C:9]2[CH:10]=[C:11]([O:14][CH3:15])[CH:12]=[CH:13][C:8]=2[CH2:7][CH2:6][N:5]([CH2:16][CH3:17])[C:4]1=[O:18])[CH3:2].FC(F)(F)C(OC(=O)C(F)(F)F)=O.[N+:32]([O-])([O-:34])=[O:33].[K+].[OH-].[Na+]>CC#N.O>[CH2:1]([CH:3]1[C:9]2[CH:10]=[C:11]([O:14][CH3:15])[C:12]([N+:32]([O-:34])=[O:33])=[CH:13][C:8]=2[CH2:7][CH2:6][N:5]([CH2:16][CH3:17])[C:4]1=[O:18])[CH3:2]

Participants

Conditions

Temperature: 0 °C

Procedure

1,3-Diethyl-8-methoxy-1,3,4,5-tetrahydro-benzo[d]azepin-2-one (564 mg, 2.28 mmol) was dissolved in 1 ml of anhydrous MeCN. The reaction was cooled to 0° C. and trifluoroacetic anhydride (3.00 mL, 21.2 mmol) and Potassium nitrate (230 mg, 2.28 mmol) were charged. The reaction was stirred for 1.5 h and then the reaction was basified with 1-2 ml of 30% NaOH solution and allowed to stir for 1 h. Pour reaction into 75 ml water and extract with 3×30 ml portions of methylene chloride. Dry the combined organic over magnesium sulfate and evaporate. Product is a yellow brown oil (625 mg). Crude material was chromatographed on a 40 g Isco column using 30-50% EtOAc in hexanes as the eluent to yield 1,3-diethyl-8-methoxy-7-nitro-1,3,4,5-tetrahydro-benzo[d]azepin-2-one (205 mg, 31%) as a tan waxy solid as a mixture of diastereomers. 1H-NMR (CDCl3) δ 7.65 (s, 1H), 6.85 (s, 1H), 4.09-3.90 (m, 5H), 3.60-3.35 (m, 3H), 3.30-3.04 (m, 2H), 2.25 (p, J=7 Hz, 1H), 1.86 (p, J=7 Hz, 1H), 1.15-1.00 (m, 6H). LC/MS (ESI+): 293 (M+H)

Workup

stirringto stir for 1 h
additionPour
extractionextract with 3×30 ml portions of methylene chloride
dry with materialDry the combined organic over magnesium sulfate
customevaporate
customCrude material was chromatographed on a 40 g Isco column

Sources & evidence

ORD record: ord-c21cfb6287f64a05b1cc0ebe824b9757
Source dataset: uspto-grants-2013_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08552186B2

Reaction notes

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