1,2-Dichloroethane → (R)-tert-butyl 4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-ylcarbamate

HRID 1809499Notes

Reaction equation

HRID 1809499 reaction equation
[C:1]([C:3]1[CH:4]=[C:5]([CH:9]=[CH:10][C:11]=1[O:12][CH:13]([CH3:15])[CH3:14])[C:6]([OH:8])=O)#[N:2].C1C=CC2N(O)N=NC=2C=1.C(Cl)CCl.O[NH:31][C:32]([C:34]1[CH:42]=[CH:41][CH:40]=[C:39]2[C:35]=1[CH2:36][CH2:37][C@H:38]2[NH:43][C:44](=[O:50])[O:45][C:46]([CH3:49])([CH3:48])[CH3:47])=[NH:33]>CN(C=O)C>[C:1]([C:3]1[CH:4]=[C:5]([C:6]2[O:8][N:33]=[C:32]([C:34]3[CH:42]=[CH:41][CH:40]=[C:39]4[C:35]=3[CH2:36][CH2:37][C@H:38]4[NH:43][C:44](=[O:50])[O:45][C:46]([CH3:48])([CH3:47])[CH3:49])[N:31]=2)[CH:9]=[CH:10][C:11]=1[O:12][CH:13]([CH3:15])[CH3:14])#[N:2]

Participants

6

Reactant 4

HCID 111,2-DichloroethaneHCID 757711-HydroxybenzotriazoleHCID 21956832RP-101124HCID 178453866HCID 178453866, compound

Product 1

HCID 67196512(R)-tert-butyl 4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-ylcarbamateYield 81%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
95 °C

Procedure

Prepared using General Procedure 4. To a solution of 3-cyano-4-isopropoxybenzoic acid (7.74 g, 37.7 mmol) in DMF (50 mL) was added HOBt (6.02 g, 44.6 mmol) and EDC (8.53 g, 44.6 mmol) at room temperature. The reaction was stirred for 2 h until complete formation of the HOBt-acid complex. (R)-tert-butyl 4-(N-hydroxycarbamimidoyl)-2,3-dihydro-1H-inden-1-ylcarbamate INT-10 (10.0 g, 34.3 mmol) was added and the reaction mixture stirred at room temperature for 2 h until the formation of INT-11, (R)-tert-butyl 4-(N-(3-cyano-4-isopropoxybenzolyloxy) carbamimidoyl)-2,3-dihydro-1H-inden-1-ylcarbamate. The mixture was partitioned between EA and NaHCO3 and the organic layer was collected and dried over MgSO4. INT-11 (16.3 g, 34.0 mmol) was re-dissolved in DMF (50 mL) and the mixture was heated to 95° C. for 12 hrs. The reaction was diluted with NaHCO3 (200 mL) and extracted with EA (3×50 mL). The organic layer was dried over Na2SO4 and concentrated under reduced pressure to produce 12.8 g (81%) of (R)-tert-butyl 4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-ylcarbamate INT-12 as a light brown solid and used without further purification in the next step. LCMS-ESI (m/z) calculated for C26H28N4O4: 460.5; found 483.2 [M+Na]+, tR=4.25 min. 1H NMR (400 MHz, CDCl3) δ 8.43 (d, J=2.1, 1H), 8.34 (dd, J=8.9, 2.2, 1H), 8.09 (d, J=7.6, 1H), 7.51 (d, J=7.5, 1H), 7.39 (t, J=7.6, 1H), 7.12 (d, J=9.0, 1H), 5.28 (d, J=8.2, 1H), 4.80 (hept, J=6.0, 1H), 3.47 (ddd, J=17.4, 8.9, 3.5, 1H), 3.27-3.03 (m, 1H), 2.68 (d, J=8.7, 1H), 1.87 (td, J=16.7, 8.5, 1H), 1.53-1.43 (m, 15H). 13C NMR (101 MHz, CDCl3) δ 173.00, 168.82, 162.70, 155.68, 145.31, 142.96, 134.05, 133.83, 128.25, 127.21, 126.79, 123.99, 116.78, 115.24, 113.52, 103.87, 79.52, 72.70, 55.72, 33.86, 31.47, 28.39, 21.70. Chiral HPLC: (R)-tert-butyl 4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-ylcarbamate was eluted using 20% i-PrOH in hexanes: >99.9% ee, tR=13.33 min. The (S)-enantiomer INT-13 was prepared in an analogous fashion using (S)-tert-butyl 4-cyano-2,3-dihydro-1H-inden-1-ylcarbamate using General Procedures 3 and 4 (tR for (S)-enantiomer=16.31 min).

Workup

  1. customPrepared
  2. customThe mixture was partitioned between EA and NaHCO3
  3. customthe organic layer was collected
  4. dry with materialdried over MgSO4
  5. dissolutionINT-11 (16.3 g, 34.0 mmol) was re-dissolved in DMF (50 mL)
  6. additionThe reaction was diluted with NaHCO3 (200 mL)
  7. extractionextracted with EA (3×50 mL)
  8. dry with materialThe organic layer was dried over Na2SO4
  9. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-0a28b70cd8f545708502e80ffb73ea87
Source dataset
uspto-grants-2013_01
Patent number
US08362048B2

Reaction notes

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