Hydrochloric Acid → (S)-benzyl 2-((2R,6R)-2,6-dimethyltetrahydro-2H-pyran-4-yl)-2-(methoxycarbonylamino)acetate

HRID 525116Notes

Reaction equation

HRID 525116 reaction equation
[CH3:1][C@@H:2]1[CH2:7][CH:6]([C@H:8]([N:19]=[C:20](C2C=CC=CC=2)C2C=CC=CC=2)[C:9]([O:11][CH2:12][C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)=[O:10])[CH2:5][C@@H:4]([CH3:33])[O:3]1.Cl.CCN(C(C)C)C(C)C.Cl[C:45](OC)=[O:46].C1C[O:52]CC1>O>[CH3:33][C@@H:4]1[CH2:5][CH:6]([C@H:8]([NH:19][C:20]([O:46][CH3:45])=[O:52])[C:9]([O:11][CH2:12][C:13]2[CH:14]=[CH:15][CH:16]=[CH:17][CH:18]=2)=[O:10])[CH2:7][C@@H:2]([CH3:1])[O:3]1

Participants

7

Reactant 5

HCID 313Hydrochloric AcidHCID 6586Methyl chloroformateHCID 8028TetrahydrofuranHCID 81531DiisopropylethylamineHCID 86668466(S)-Benzyl 2-((2R,6R)-2,6-dimethyltetrahydro-2H-pyran-4-yl)-2-(diphenylmethyleneamino)acetate

Product 1

HCID 86668465(S)-benzyl 2-((2R,6R)-2,6-dimethyltetrahydro-2H-pyran-4-yl)-2-(methoxycarbonylamino)acetate

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

(S)-Benzyl 2-((2R,6R)-2,6-dimethyltetrahydro-2H-pyran-4-yl)-2-(diphenylmethyleneamino)acetate (Cap-2, step d.2) (129.6 mg, 0.294 mmol) was dissolved in THF (2 mL) and then treated with 2N HCl (1.0 mL, 2.1 mmol) in water. The reaction was stirred for 2 h and then concentrated under a stream of nitrogen overnight. The crude residue was dissolved in DCM (2 mL) and DIPEA (0.21 mL, 1.2 mmol) and then treated with methyl chloroformate (0.032 mL, 0.41 mmol) and stirred at RT for 4 h. The reaction was diluted with water (˜2.5 mL) and extracted with DCM (4×2 mL). The combined organic phase was concentrated under a stream of nitrogen overnight and the residue was purified with a Biotage® Horizon (4 g SiO2, 10-50% EtOAc/hexanes) to yield (S)-benzyl 2-((2R,6R)-2,6-dimethyltetrahydro-2H-pyran-4-yl)-2-(methoxycarbonylamino)acetate (Cap-2, step e) (56 mg) as a colorless glass. LC-MS retention time 3.338 min; m/z 335.99 [M+H]+. LC data was recorded on a Shimadzu LC-10AS liquid chromatograph equipped with a Phenomenex-Luna 3u C18 2.0×50 mm column using a SPD-10AV UV-Vis detector at a detector wave length of 220 nM. The elution conditions employed a flow rate of 0.8 mL/min, a gradient of 100% solvent A/0% solvent B to 0% solvent A/100% solvent B, a gradient time of 4 min, a hold time of 1 min, and an analysis time of 5 min where solvent A was 5% MeOH/95% H2O/10 mM ammonium acetate and solvent B was 5% H2O/95% MeOH/10 mM ammonium acetate. MS data was determined using a Micromass Platform for LC in electrospray mode. 1H NMR (400 MHz, D4-MeOH) δ ppm 7.29-7.42 (m, 5H), 5.28 (d, J=12.0 Hz, 1H), 5.09 (d, J=12.0 Hz, 1H), 4.10-4.20 (m, 2H), 3.68-3.78 (m, 1H), 3.65 (s, 3H), 2.22-2.36 (m, 1H), 1.42-1.54 (m, 2H), 1.29-1.38 (m, 1H), 1.17 (d, J=6.8 Hz, 3H), 1.04 (d, J=6.0 Hz, 3H), 0.89-1.00 (m, 1H).

Workup

  1. concentrationconcentrated under a stream of nitrogen overnight
  2. dissolutionThe crude residue was dissolved in DCM (2 mL)
  3. stirringstirred at RT for 4 h
  4. extractionextracted with DCM (4×2 mL)
  5. concentrationThe combined organic phase was concentrated under a stream of nitrogen overnight
  6. customthe residue was purified with a Biotage® Horizon (4 g SiO2, 10-50% EtOAc/hexanes)

Sources & evidence

ORD record
ord-fa3271f1e1184c538797d0f4f75b5d0c
Source dataset
uspto-grants-2016_05
Patent number
US09340520B2

Reaction notes

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