4-Hydroxybenzaldehyde → 1-(4-Hydroxybenzyl)-1,2,3,6-tetrahydropyridine

HRID 236547Notes

Reaction equation

HRID 236547 reaction equation
[OH:1][C:2]1[CH:9]=[CH:8][C:5]([CH:6]=O)=[CH:4][CH:3]=1.[NH:10]1[CH2:15][CH:14]=[CH:13][CH2:12][CH2:11]1.Cl.C([BH3-])#N.[Na+]>CO>[OH:1][C:2]1[CH:9]=[CH:8][C:5]([CH2:6][N:10]2[CH2:11][CH:12]=[CH:13][CH2:14][CH2:15]2)=[CH:4][CH:3]=1

Participants

6

Reactant 4

HCID 1264-HydroxybenzaldehydeHCID 313Hydrochloric Acid2×HCID 127501,2,3,6-TetrahydropyridineHCID 5003444Sodium cyanoborohydride

Product 1

HCID 202160941-(4-Hydroxybenzyl)-1,2,3,6-tetrahydropyridine

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of 4-hydroxybenzaldehyde (6.1 g.) and 1,2,3,6-tetrahydropyridine (8.3 g.) in methanol (70 ml.) was adjusted to pH7 by addition of ethereal hydrogen chloride. Sodium cyanoborohydride (3.15 g.) was then added in portions to the stirred solution at 25° C. The mixture was stirred at 20°-25° C. for four days, evaporated, and water (100 ml.) added to the resultant residue. The mixture obtained was adjusted to pH2 with dilute hydrochloric acid and extracted with ether (2×50 ml.). The extracts were discarded. The aqueous phase was separated and adjusted to pH9 with 10% w/v sodium carbonate solution, to give crude 1-(4-hydroxybenzyl)-1,2,3,6-tetrahydropyridine as a solid. This solid was dissolved in acetone (100 ml.) and the solution acidified to pH2 with ethereal hydrogen chloride to give 1-(4-hydroxybenzyl)-1,2,3,6-tetrahydropyridine hydrochloride (6.7 g.), m.p. 234°-236° C. (after recrystallisation from methanol/ethyl acetate.)

Workup

  1. customevaporated
  2. additionwater (100 ml.) added to the resultant residue
  3. customThe mixture obtained
  4. extractionextracted with ether (2×50 ml.)
  5. customThe aqueous phase was separated

Sources & evidence

ORD record
ord-924f79de1fbf488ea1f53b0d7db8de49
Source dataset
uspto-grants-1987_02
Patent number
US04645771

Reaction notes

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