Methylparaben → (RS)-methyl 4-[2-(N-ethyl-4,4-dimethyl-1,2,3,4-tetrahydroquinolin-6-yl)-heptyloxy]-benzoate

HRID 394945Notes

Reaction equation

HRID 394945 reaction equation
[CH2:1]([N:3]1[C:12]2[C:7](=[CH:8][C:9]([CH:13]([CH2:16][CH2:17][CH2:18][CH2:19][CH3:20])[CH2:14][OH:15])=[CH:10][CH:11]=2)[C:6]([CH3:22])([CH3:21])[CH2:5][CH2:4]1)[CH3:2].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.O[C:43]1[CH:52]=[CH:51][C:46]([C:47]([O:49][CH3:50])=[O:48])=[CH:45][CH:44]=1.N(C(OCC)=O)=NC(OCC)=O>C1COCC1.CCOCC>[CH2:1]([N:3]1[C:12]2[C:7](=[CH:8][C:9]([CH:13]([CH2:16][CH2:17][CH2:18][CH2:19][CH3:20])[CH2:14][O:15][C:43]3[CH:52]=[CH:51][C:46]([C:47]([O:49][CH3:50])=[O:48])=[CH:45][CH:44]=3)=[CH:10][CH:11]=2)[C:6]([CH3:21])([CH3:22])[CH2:5][CH2:4]1)[CH3:2]

Participants

7

Reactant 4

HCID 7456MethylparabenHCID 11776TriphenylphosphineHCID 220568ethyl N-ethoxycarbonyliminocarbamateHCID 17949416(RS)-2-(N-ethyl-4,4-dimethyl-1,2,3,4-tetrahydroquinolin-6-yl)-heptanol

Product 1

HCID 18177841(RS)-methyl 4-[2-(N-ethyl-4,4-dimethyl-1,2,3,4-tetrahydroquinolin-6-yl)-heptyloxy]-benzoateYield 46.5%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent

Procedure

1 g of (RS)-2-(N-ethyl-4,4-dimethyl-1,2,3,4-tetrahydroquinolin-6-yl)-heptanol dissolved in 20 ml THF were treated with 950 mg of triphenylphosphine, 550 mg of methyl 4-hydroxybenzoate and 0.57 ml of diethyl azodicarboxylate. The reaction mixture was heated to reflux for 6 hours. The mixture was diluted with 100 ml of ether and washed with two portions of 25 ml of water and one portion of 25 ml of sat. aq. sodium chloride solution. The organic phase was dried over MgSO4. The solvents were removed in vacuo and the resulting yellow oil was purified by flash chromatography (SiO2, 3% ethyl acetate/hexanes), giving 670 mg (RS)-methyl 4-[2-(N-ethyl-4,4-dimethyl-1,2,3,4-tetrahydroquinolin-6-yl)-heptyloxy]-benzoate as a pale yellow oil. The ester (670 mg), dissolved in 5 ml THF/5 ml H2O/5 ml methanol, was treated with 260 mg of lithium hydroxide hydrate. The mixture was stirred at 40° C. for 6 hours. The mixture was diluted with 5 ml water and acidified to pH 2 with 1N hydrochloric. The resulting suspension was taken in 20 ml ether and the phases were separated. The aqueous phase was extracted with three portions of 10 ml ether. The combined extracts were dried over MgSO4. The solvent was removed in vacuo and the crude product was purified by preparative tlc (10% methanol/methylene chloride), yielding 320 mg of a pale yellow oil. 1H NMR (CDCl3): 8.01 (d, J=9.0 HZ, 2H), 6.98 (d, J=2.1 Hz, 1H), 6.95-6.85 (m, 3H), 6.52 (d, J=8.4 Hz, 1H), 4.64 (quint, J=5.8 Hz, 1H), 3.32 (q, J=7.1 Hz, 2H), 3.25-3.15 (m, 2H), 2.88 (dd, J=14.1, 5.9 Hz, 1H), 2.78 (dd, J=14.1, 5.9 Hz, 1H), 1.80-1.65 (m, 4H), 1.55-1.25 (m, 6H), 1.24 (s, 3H), 1.18 (s, 3H), 1.11 (t, J=7.1 Hz, 3H), 0.86 (t, J=6.7 Hz, 3H).

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureto reflux for 6 hours
  3. washwashed with two portions of 25 ml of water and one portion of 25 ml of sat. aq. sodium chloride solution
  4. dry with materialThe organic phase was dried over MgSO4
  5. customThe solvents were removed in vacuo
  6. customthe resulting yellow oil was purified by flash chromatography (SiO2, 3% ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-d21ab8a8fff4493fab9ef7697a459e7f
Source dataset
uspto-grants-2003_08
Patent number
US06603012B2

Reaction notes

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