Tetrahydrofuran → Pyrazolo(5,1-a)isoquinoline-1-methanol, 5,6-dihydro-2-phenyl-

HRID 616723Notes

Reaction equation

HRID 616723 reaction equation
[H-].[H-].[H-].[H-].[Li+].[Al+3].O1CCCC1.[C:12]1([C:18]2[C:30]([C:31](O)=[O:32])=[C:21]3[C:22]4[C:27]([CH2:28][CH2:29][N:20]3[N:19]=2)=[CH:26][CH:25]=[CH:24][CH:23]=4)[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1.[OH-].[Na+]>O>[C:12]1([C:18]2[C:30]([CH2:31][OH:32])=[C:21]3[C:22]4[C:27]([CH2:28][CH2:29][N:20]3[N:19]=2)=[CH:26][CH:25]=[CH:24][CH:23]=4)[CH:13]=[CH:14][CH:15]=[CH:16][CH:17]=1

Participants

6

Reactant 4

HCID 8028Tetrahydrofuran2×HCID 14798Sodium HydroxideHCID 12948308HCID 12948308, compoundHCID 21226445Aluminium lithium hydride

Product 1

HCID 3045618Pyrazolo(5,1-a)isoquinoline-1-methanol, 5,6-dihydro-2-phenyl-

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

To 0.76 g. of LiAlH4 in 50 ml. of tetrahydrofuran, 6.08 g. of the methyl ester of 2-phenyl-5,6-dihydro-pyrazolo[5,1-a]isoquinoline-1-carboxylic acid dissolved in 75 ml. of tetrahydrofuran is added. The mixture is stirred for four hours at room temperature, then refluxed for one hour. To the reaction mixture at about 0° C. are subsequently added 0.76 ml. of water, 0.76 ml. of 20% NaOH and again 2.3 ml. of water. After addition of 75 ml. of ethyl ether, the inorganic precipitate is filtered off and the organic solution is evaporated to dryness to give 4 g. of the title product which, crystallized from ethanol, melts at 185°-7° C.

Workup

  1. temperaturerefluxed for one hour
  2. customat about 0° C.
  3. additionAfter addition of 75 ml
  4. filtrationof ethyl ether, the inorganic precipitate is filtered off
  5. customthe organic solution is evaporated to dryness
  6. customto give 4 g
  7. customof the title product which, crystallized from ethanol, melts at 185°-7° C.

Sources & evidence

ORD record
ord-69337e96e1094dcd8d86924472d7ca34
Source dataset
uspto-grants-1978_02
Patent number
US04075342

Reaction notes

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