Sulfuric Acid → 4-Bromo-2-cyclopentyl-5-nitrophenyl methyl carbonate
Reaction equation
OS(O)(=O)=O.[C:6](=[O:22])([O:20][CH3:21])[O:7][C:8]1[CH:13]=[CH:12][C:11]([Br:14])=[CH:10][C:9]=1[CH:15]1[CH2:19][CH2:18][CH2:17][CH2:16]1.[N+:23]([O-])([O-:25])=[O:24].[K+]>>[C:6](=[O:22])([O:20][CH3:21])[O:7][C:8]1[CH:13]=[C:12]([N+:23]([O-:25])=[O:24])[C:11]([Br:14])=[CH:10][C:9]=1[CH:15]1[CH2:19][CH2:18][CH2:17][CH2:16]1Participants
Conditions
- Temperature
- -10 °C
Procedure
Concentrated H2SO4 (115 mL) was added to 4-bromo-2-cyclopentylphenyl methyl carbonate (26.09 g, 87.21 mmol) and the mixture stirred and cooled to −10° C. KNO3 (13.22 g, 130.80 mmol) was then added in portions with continuous stirring. The reaction was stirred at −10° C. for 1 h then quenched with ice resulting in precipitation of an off-white solid. The solid was filtered, washed with water and dried to provide the product. The water phase was extracted with dichloromethane (3×10 mL) and the combined organic extracts dried over Na2SO4. Purification by silica gel chromatography (5-20% ethyl acetate/hexane) provided additional 4-bromo-2-cyclopentyl-5-nitrophenyl methyl carbonate (combined 21.72 g, 72% yield). 1H NMR (400.0 MHz, DMSO-d6) δ 8.12 (s, 1H), 7.88 (s, 1H), 3.88 (d, J=5.7 Hz, 3H), 3.13 (dd, J=9.4, 17.2 Hz, 1H), 1.96-1.92 (m, 2H), 1.80-1.75 (m, 2H), 1.68-1.54 (m, 4H).
Workup
- stirringThe reaction was stirred at −10° C. for 1 h
- customthen quenched with ice resulting in precipitation of an off-white solid
- filtrationThe solid was filtered
- washwashed with water
- customdried
- customto provide the product
- extractionThe water phase was extracted with dichloromethane (3×10 mL)
- dry with materialthe combined organic extracts dried over Na2SO4
- customPurification by silica gel chromatography (5-20% ethyl acetate/hexane)
Sources & evidence
- ORD record
- ord-b12cff3fdd9943118914f365446b9140
- Source dataset
- uspto-grants-2013_02
- Patent number
- US08367660B2
Reaction notes
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