tert-Butyl acetate → methyl 2-(tert-butoxy)-2-(1-(4-methoxybenzyl)-6-methyl-4-(5-methylchroman-6-yl)-7-oxo-6,7-dihydro-1H-pyrrolo[2,3-c]pyridin-5-yl)acetate

HRID 1473242Notes

Reaction equation

HRID 1473242 reaction equation
[OH:1][CH:2]([C:7]1[N:12]([CH3:13])[C:11](=[O:14])[C:10]2[N:15]([CH2:18][C:19]3[CH:24]=[CH:23][C:22]([O:25][CH3:26])=[CH:21][CH:20]=3)[CH:16]=[CH:17][C:9]=2[C:8]=1[C:27]1[C:28]([CH3:37])=[C:29]2[C:34](=[CH:35][CH:36]=1)[O:33][CH2:32][CH2:31][CH2:30]2)[C:3]([O:5][CH3:6])=[O:4].C(O[C:42]([CH3:45])([CH3:44])[CH3:43])(=O)C.Cl(O)(=O)(=O)=O>>[C:42]([O:1][CH:2]([C:7]1[N:12]([CH3:13])[C:11](=[O:14])[C:10]2[N:15]([CH2:18][C:19]3[CH:20]=[CH:21][C:22]([O:25][CH3:26])=[CH:23][CH:24]=3)[CH:16]=[CH:17][C:9]=2[C:8]=1[C:27]1[C:28]([CH3:37])=[C:29]2[C:34](=[CH:35][CH:36]=1)[O:33][CH2:32][CH2:31][CH2:30]2)[C:3]([O:5][CH3:6])=[O:4])([CH3:45])([CH3:44])[CH3:43]

Participants

4

Procedure

An ice cold solution of methyl 2-hydroxy-2-(1-(4-methoxybenzyl)-6-methyl-4-(5-methylchroman-6-yl)-7-oxo-6,7-dihydro-1H-pyrrolo[2,3-c]pyridin-5-yl)acetate (325 mg, 0.647 mmol) in tert-butyl acetate (8735 μl, 64.7 mmol) was treated with perchloric acid (55.6 μl, 0.647 mmol), and stirred for 20 min. The reaction was then kept in the refrigerator without stirring for 2 days. The reaction was quenched with sat. NaHCO3 at 0° C., extracted with EtOAc 2×, washed with Brine, dried with Na2SO4, filtered, and concentrated. Purification with column chromatography (0-100% EtOAc/Hexane) gave methyl 2-(tert-butoxy)-2-(1-(4-methoxybenzyl)-6-methyl-4-(5-methylchroman-6-yl)-7-oxo-6,7-dihydro-1H-pyrrolo[2,3-c]pyridin-5-yl)acetate (219.3 mg, 0.393 mmol, 60.7% yield, racemate) as white solid. The racemate was resolved using a Chiralpak IC column (30×250 mm) with isocratic conditions of 10% EtOH in hexane. The flow rate was 40 mL/min and the baseline was monitored at 280 nm using an Agilent 1100 series prep LC. The third isomer eluting from the column was isolated to afford (S)(M)-methyl 2-(tert-butoxy)-2-(1-(4-methoxybenzyl)-6-methyl-4-(5-methylchroman-6-yl)-7-oxo-6,7-dihydro-1H-pyrrolo[2,3-c]pyridin-5-yl)acetate (52.9 mg, 0.095 mmol, 14.6% yield) as clear oil: 1H NMR (400 MHz, CHLOROFORM-d) ppm 7.29 (d, J=8.5 Hz, 2H), 6.99-6.91 (m, 2H), 6.85 (d, J=8.5 Hz, 2H), 6.69 (d, J=8.4 Hz, 1H), 5.86 (d, J=14.6 Hz, 1H), 5.71-5.61 (m, 2H), 5.09 (s, 1H), 4.20 (t, J=5.2 Hz, 2H), 3.78 (s, 3H), 3.72 (s, 3H), 3.65 (s, 3H), 2.76-2.62 (m, 2H), 2.13-2.04 (m, 2H), 1.91 (s, 3H), 1.11 (s, 9H); LCMS (m/z) ES+=559 (M+1).

Workup

  1. stirringwithout stirring for 2 days
  2. customThe reaction was quenched with sat. NaHCO3 at 0° C.
  3. extractionextracted with EtOAc 2×
  4. washwashed with Brine
  5. dry with materialdried with Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customPurification with column chromatography (0-100% EtOAc/Hexane)

Sources & evidence

ORD record
ord-04ca5363f0ff497789cfb74dcb58aaa4
Source dataset
uspto-grants-2015_04
Patent number
US09012642B2

Reaction notes

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