Acetic Acid → HCID 53908906, compound

HRID 265010Notes

Reaction equation

HRID 265010 reaction equation
C([BH3-])#N.[Na+].[F:5][C:6]1[CH:7]=[CH:8][C:9]([O:22][CH3:23])=[C:10]2[C:15]=1[O:14][CH2:13][C@H:12]([NH:16][CH:17]([CH2:20][CH3:21])[CH2:18][CH3:19])[CH2:11]2.[CH:24](=O)[CH2:25][CH3:26].C(O)(=O)C>CO>[F:5][C:6]1[CH:7]=[CH:8][C:9]([O:22][CH3:23])=[C:10]2[C:15]=1[O:14][CH2:13][C@H:12]([N:16]([CH:17]([CH2:18][CH3:19])[CH2:20][CH3:21])[CH2:24][CH2:25][CH3:26])[CH2:11]2

Participants

6

Reactant 4

HCID 176Acetic AcidHCID 527Propanal2×HCID 5003444Sodium cyanoborohydrideHCID 53693748(R)-8-fluoro-5-methoxy-3-(N-3-pentylamino)chroman

Product 1

HCID 53908906HCID 53908906, compoundYield 94.4%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

Sodiumcyanoborohydride (1.3 g, 20.7 mmol) was added during 10 min. to a stirred solution of (R)-8-fluoro-5-methoxy-3-(N-3-pentylamino)chroman (3.69 g, 13.8 mmol) and propionaldehyde (5 ml, 69.3 mmol) in 100 ml dry MeOH. The pH was adjusted with acetic acid to pH 6. The solution was stirred in room temp. for 18 hours and propionaldehyde (1 ml, 13.7 mmol) was added. After stirring at room temp. for 3.5 hours the solution was concentrated, and the residue was partitionated between 100 ml 2MNH3 and 200 ml ether. Extraction with 2×200 ml ether and drying of the combined organic layers (Na2SO4) gave after evaporation a crude product. Purification by flash chromatography on silica with hexane:acetone 20:1 gave 4.03 g of (R)-8-fluoro-5-methoxy-3-(N-3-pentyl-N-n-propylamino)chroman as an uncolored oil. [α]D22 -83° (c 1.08 in MeOH).

Workup

  1. stirringAfter stirring at room temp. for 3.5 hours the solution
  2. concentrationwas concentrated
  3. extractionExtraction with 2×200 ml ether
  4. dry with materialdrying of the combined organic layers (Na2SO4)
  5. customgave
  6. customafter evaporation a crude product
  7. customPurification by flash chromatography on silica with hexane:acetone 20:1

Sources & evidence

ORD record
ord-522ea72600c149cf9cb638d1fc381bf6
Source dataset
uspto-grants-1997_07
Patent number
US05646309

Reaction notes

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