Sodium Azide → (3S,4S)-benzyl 3-azido-4-methylpyrrolidine-1-carboxylate

HRID 1487302Notes

Reaction equation

[CH3:1][C@@H:2]1[C@@H:6](OS(C2C=CC(C)=CC=2)(=O)=O)[CH2:5][N:4]([C:18]([O:20][CH2:21][C:22]2[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=2)=[O:19])[CH2:3]1.[N-:28]=[N+:29]=[N-:30].[Na+]>CN(C=O)C>[N:28]([C@H:6]1[C@@H:2]([CH3:1])[CH2:3][N:4]([C:18]([O:20][CH2:21][C:22]2[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=2)=[O:19])[CH2:5]1)=[N+:29]=[N-:30]

Participants

Conditions

Temperature: 85 °C

Procedure

(3S,4R)-Benzyl 3-methyl-4-(tosyloxy)pyrrolidine-1-carboxylate (20 g, 51.4 mmol) was dissolved in DMF (42.8 ml). Sodium azide (5.68 g, 87 mmol) was added at rt and heated up to 85° C. overnight. LCMS shows a complete conversion. The reaction mixture was cooled to rt, quenched with ice water, extracted with ethyl acetate. Organic phases were combined, washed with water, brine, then dried with Na2SO4. After concentration, (3S,4S)-benzyl 3-azido-4-methylpyrrolidine-1-carboxylate (13 g, 97% yield) was obtained as a yellowish oil and used directly for the next reduction. 1H NMR (400 MHz, chloroform-d) δ ppm 7.29-7.44 (5H, m), 5.08-5.22 (2H, m), 3.94-4.04 (1H, m), 3.52-3.76 (3H, m), 3.00-3.15 (1H, m), 2.29-2.48 (1H, m), 1.13 (3H, t, J=7.04 Hz); LCMS (CHROMOLITH® RP-18e 2.0×50 mm, 0.8 mL/min, Solvent A: 10% MeOH/water with 0.1% TFA, Solvent B: 90% MeOH/water with 0.1% TFA, gradient with 0-100% B over 4 minutes) retention time: 3.41 min; MS(ES+) m/z: 261.0 (M+H+).

Workup

temperatureThe reaction mixture was cooled to rt
customquenched with ice water
extractionextracted with ethyl acetate
washwashed with water, brine
dry with materialdried with Na2SO4
concentrationAfter concentration

Sources & evidence

ORD record: ord-43c4fbb9a2564785b61e22675a9895ee
Source dataset: uspto-grants-2016_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09428511B2

Reaction notes

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