HCID 66811108, compound → HCID 57911412, compound

HRID 1666129Notes

Reaction equation

HRID 1666129 reaction equation
[F:1][C:2]1[C:7]([F:8])=[CH:6][CH:5]=[CH:4][C:3]=1[C@H:9]1[CH2:19][CH2:18][C@H:17](O)[C:12]2=[N:13][CH:14]=[CH:15][CH:16]=[C:11]2[CH2:10]1.FC1C(F)=CC=CC=1[C@H]1CC[C@@H](O)C2=NC=CC=C2C1>C(Cl)Cl>[F:1][C:2]1[C:7]([F:8])=[CH:6][CH:5]=[CH:4][C:3]=1[CH:9]1[CH2:19][CH2:18][CH2:17][C:12]2=[N:13][CH:14]=[CH:15][CH:16]=[C:11]2[CH2:10]1

Participants

4

Reactant 2

HCID 66811108HCID 66811108, compoundHCID 66811576HCID 66811576, compound

Product 1

HCID 57911412HCID 57911412, compound

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Racemic trans-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-ol and cis-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-ol. In a 100 mL round-bottomed flask was 6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine (106 mg, 0.409 mmol) in CH2Cl2 (4 ml) to give a colorless solution. mCPBA (137 mg, 0.613 mmol) was added and the resulted solution was stirred at rt overnight. 19 h: LCMS indicated complete conversion to the N-oxide. The mixture was diluted with EtOAc and washed with 1N NaOH solution. The organic layer was washed with brine, dried with Na2SO4, and concentrated in vacuo to a white solid. It was carried onto next reaction without further purification and characterizations. MS(ESI)[M+H+]=276.13. In a 100 mL round-bottomed flask was 6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine 1-oxide (113 mg, 0.409 mmol) (light yellow oil, azeotroped with dry benzene) in CH2Cl2 (4 mL) to give a light yellow solution. After cooling to 0° C., TFAA (0.144 mL, 1.023 mmol) was added, and the mixture was stirred at r.t. for 4 h. LCMS showed only 10% desired product and mainly SM (or maybe acylated N-oxide, slow rearrangement). Another 0.15 ml TFAA was added and the mixture was stirred at rt overnight. LCMS showed a little better. The mixture was refluxed at 45° C. for 4 h and the reaction didn't improve. Volatiles were stripped off and 2 ml acetic anhydride was added and the mixture was heated at 130° C. (preheated bath) for 1.5 h. LCMS showed no sm. It was cooled down and diluted with EtOAc. Basified with NaOH solution and the layers were separated. The organic layer was washed with water and concentrated to a tan oil. It was then dissolved in 2 ml THF and treated with 1.5 ml 1N NaOH for 1 h. LCMS showed mainly one peak as the desired product (M+H=276). The mixture was partitioned between EtOAc and water. The organic layer was separated and washed with brine, dried and concentrated to a tan oil. Purification by FCC up to 50% EtOAc/hexane afforded two compounds (very close spots on TLC): a and b. Further elution up to 80% EtOAc/hexane gave a more polar peak as c. As proved by 1H NMR, a was the desired trans-alcohol (32.3 mg, 29%) (the analytical data was the same as previously described); b was the dehydrated product (10.4 mg, 9.9%); and c was the cis-alcohol (36 mg, 32%). The cis-alcohol was much more polar that the trans-alcohol (Rf=0.16 for cis and 0.77 for trans in 50% EtOAc/hexanes). 1H NMR for the cis-alcohol: 1H NMR (500 MHz, CHLOROFORM-d) δ ppm 8.26 (d, J=4.58 Hz, 1 H) 7.30 (d, J=7.63 Hz, 1 H) 7.04 (dd, J=7.32, 4.88 Hz, 1 H) 6.85-6.98 (m, 2 H) 6.79 (t, J=6.87 Hz, 1 H) 5.37 (br.s., 1 H) 5.01 (dd, J=7.17, 3.81 Hz, 1 H) 3.28-3.52 (m, 2 H) 2.93 (d, J=13.73 Hz, 1 H) 2.17-2.33 (m, 1 H) 1.89-2.15 (m, 3 H).

Workup

  1. customIn a 100 mL round-bottomed flask was

Sources & evidence

ORD record
ord-f9e11d0a9e29428493df5504009c170a
Source dataset
uspto-grants-2011_10
Patent number
US08044043B2

Reaction notes

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