Oxalyl chloride → HCID 22714985, compound

Preparation of the intermediate isocyanate was carried out via a Curtius rearrangement. See Capson, T. L. et al., Tetrahedron Lett., 25, 3515 (1984) and references herein. To a solution of the compound prepared in (2) (3.03 g, 14.3 mmol) in CH2Cl2 (20 mL) was added oxalylchloride (130 mL, 15.0 mmol) and the resulting mixture was stirred 3 h at room temperature. The residue obtained after evaporation of the solvent was diluted with THF (10 mL) and injected with vigorous stirring to a ice-cooled solution of Na2N3 (3.70 g, 57 mmol) in H2O (20 mL) and acetone (50 mL). After 15 min at 0° C. and 1 min at room temperature, the solution was extracted with Et2O (4×50 mL) and dried (Na2SO4). The residue obtained after evaporation of solvents was refluxed in toluene for 1 h 30 to provide, upon solvent removal, 2.85 g (79%) of a slightly yellow oil: IR (neat, cm-1) 2269, 1598, 1433, 1252, 1228, 846, 788; 1H NMR (300 MHz, CDCl3) δ 0.38 (d, J=1.9 Hz, 9H), 6.82 (br t, J=8.3 Hz, 1H), 6.90 (br d, J=8.2 Hz, 1H), 7.25 (ddd, J1 =J2 =8.1 Hz, J3 =6.6 Hz, 1H); 13C NMR (75 MHz, CDCl3) δ 0.4, 112.6 (d, JCF =26 Hz), 120.5, 122.5, 131.5, 139.2, 167.4 (d, JCF =241 Hz)

1. customThe residue obtained
2. customafter evaporation of the solvent
3. additionwas diluted with THF (10 mL)
4. stirringwith vigorous stirring to a ice-
5. waitAfter 15 min at 0° C.
6. extraction1 min at room temperature, the solution was extracted with Et2O (4×50 mL)
7. dry with materialdried (Na2SO4)
8. customThe residue obtained
9. customafter evaporation of solvents
10. temperaturewas refluxed in toluene for 1 h 30
11. customto provide, upon solvent removal, 2.85 g (79%) of a slightly yellow oil

ORD record

ord-1ceda98fbe6248d6a1d576adae5e2847

Source dataset

uspto-grants-2000_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06150343