Reaction #7101

Reaction equation

ether

3-(7′-nitro-1′,2′-dihydro-2′-oxospiro-[cyclohexane-1,3′-[3H]indol]-5′-yl)-5-fluorobenzonitrile

tin (11) chloride dihydrate

→

title compound

Yield 52.2%

3-(7′-Amino-1′,2′-dihydro-2′-oxospiro[cyclohexane-1,3′-[3H]indol]-5′-yl)-5-fluoro-benzonitrile

Yield 52.2%

Solvents

HCl

acetic acid

hydrochloric acid

Conditions

Workup

1. 1
   OtherThe layers were separated
2. 2
   Extractionthe aqueous phase was extracted with ether (2×20 mL)
3. 3
   Washwashed sequentially with water (2×20 mL), saturated aqueous NaHCO3 (20 mL), and brine (20 mL)
4. 4
   DryingThe solution was dried over MgSO4
5. 5
   Filtrationfiltered
6. 6
   Concentrationconcentrated in vacuo
7. 7
   OtherThe residue was purified by flash column chromatography on silica gel (eluting with 40% EtOAc/hexane)

Procedure

To a solution of 3-(7′-nitro-1′,2′-dihydro-2′-oxospiro-[cyclohexane-1,3′-[3H]indol]-5′-yl)-5-fluorobenzonitrile (1.0 eq, 0.16 g, 0.4 mmol) in glacial acetic acid (4 mL) at room temperature was added a solution of tin (11) chloride dihydrate (0.25 g, 1.1 mmol) in hydrochloric acid (2 mL). The yellow mixture was boiled for 30 min at which point the yellow color disappeared. After cooling to room temperature, 1N HCl (10 mL) and ether (20 mL) were added. The layers were separated and the aqueous phase was extracted with ether (2×20 mL). The organic layers were combined, washed sequentially with water (2×20 mL), saturated aqueous NaHCO3 (20 mL), and brine (20 mL). The solution was dried over MgSO4, filtered, and concentrated in vacuo. The residue was purified by flash column chromatography on silica gel (eluting with 40% EtOAc/hexane) to give the title compound (70 mg, 50%) as an oil which crystallized upon addition of 10% EtOAc/hexanes, mp 241–3° C. 1H NMR (DMSO-d6; 400 MHz) δ 1.50–1.75 (m, 8H), 1.82–1.95(m, 2H), 4.98 (s, 2H), 6.90 (d, 1H, J=1.8 Hz), 7.09 (d, 1H, J=1.5 Hz), 7.75 (m, 2H), 7.90 (‘s’, 1H), 9.96 (bs, 1H). MS ((+)−APCI) m/z 336 [(M+H)+]. Anal. Calcd for C20H18FN3O: C, 71.63; H, 5.41; N, 12.18. Found: C, 71.16; H, 5.58; N, 12.18.

Source