2-Bromopropane → Ethyl (1aR,5aR)-2-Isopropyl-1a,2,5,5a-tetrahydro-1H-2,3-diazacyclopropa[a]pentalene-4-carboxylate

HRID 1623894Notes

Reaction equation

[CH2:1]([O:3][C:4]([C:6]1[C:7]2[CH2:8][C@H:9]3[CH2:14][C@H:10]3[C:11]=2[NH:12][N:13]=1)=[O:5])[CH3:2].Br[CH:16]([CH3:18])[CH3:17]>CN(C=O)C.CCOC(C)=O>[CH:16]([N:12]1[C:11]2[C@@H:10]3[CH2:14][C@@H:9]3[CH2:8][C:7]=2[C:6]([C:4]([O:3][CH2:1][CH3:2])=[O:5])=[N:13]1)([CH3:18])[CH3:17]

Participants

Conditions

Temperature: 25 °C

Procedure

(1aR,5aR)-1a,2,5,5a-Tetrahydro-1H-2,3-diazacyclopropa[a]pentalene-4-carboxylic acid ethyl ester (0.100 g, 0.520 mmol) (from Example 1.4, Step A) was dissolved in anhydrous DMF (5.20 mL). CsCO3 (0.678 g, 2.081 mmol) was added to give a suspension which was stirred at 25° C. for several minutes. 2-Bromopropane (0.098 mL, 1.041 mmol) was added dropwise at 25° C. After stirring for 4 h, the reaction was diluted with EtOAc (50 mL), washed with water (2×10 mL), brine, and dried over MgSO4. The solvent was evaporated under reduced pressure. The oil residue was purified by silica gel column chromatography to give the title compound as an oil (0.073 g). LCMS m/z=235.3 [M+H]+; 1H NMR (400 MHz, CDCl3) ppm 0.29-0.35 (m, 1H), 1.12 (td, J=8.02, 4.93 Hz, 1H), 1.34 (t, J=7.20 Hz, 3H), 1.46 (dd, J=15.16, 6.57 Hz, 6H), 2.04-2.12 (m, 1H), 2.16-2.24 (m, 1H), 2.74-2.82 (m, 1H), 2.90-2.99 (m, 1H), 4.27 (q, J=7.07 Hz, 2H), 5.31-5.43 (m, 1H).

Workup

customto give a suspension which
stirringAfter stirring for 4 h
washwashed with water (2×10 mL), brine
dry with materialdried over MgSO4
customThe solvent was evaporated under reduced pressure
customThe oil residue was purified by silica gel column chromatography

Sources & evidence

ORD record: ord-dcf780a0001648eebbeeeca345f00492
Source dataset: uspto-grants-2014_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08778950B2

Reaction notes

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