M-Cresol → 8-Methyl-1,2,3,4-tetrahydro-chromeno[3,4-c]pyridin-5-one

HRID 851195Notes

Reaction equation

HRID 851195 reaction equation
S(=O)(=O)(O)O.[CH3:6][C:7]1[CH:8]=[C:9]([OH:13])[CH:10]=[CH:11][CH:12]=1.Cl.C[O:16][C:17]([CH:19]1[C:24](=O)[CH2:23][CH2:22][NH:21][CH2:20]1)=O.[OH-].[NH4+]>>[CH3:6][C:7]1[CH:12]=[CH:11][C:10]2[C:24]3[CH2:23][CH2:22][NH:21][CH2:20][C:19]=3[C:17](=[O:16])[O:13][C:9]=2[CH:8]=1

Participants

5

Reactant 4

HCID 342M-CresolHCID 1118Sulfuric AcidHCID 14923Ammonium HydroxideHCID 2724028Methyl 4-oxopiperidine-3-carboxylate hydrochloride

Product 1

HCID 106087088-Methyl-1,2,3,4-tetrahydro-chromeno[3,4-c]pyridin-5-oneYield 20.9%

Conditions

Temperature
5 °C

Procedure

An 80% sulfuric acid solution (80 ml) is stirred and cooled to 5° C. in an ice bath and 3-methylphenol (10.8 ml, 0.10 moles) is added, followed by methyl-4-oxo-3-piperidine carboxylate hydrochloride (20.0 g, 0.10 moles). The mixture is allowed to warm gradually to room temperature. After 48 hours the solution is poured into ice water (400 ml) and stirred until a crystalline precipitate forms. Concentrated ammonium hydroxide is added until the mixture is strongly basic. After one hour the precipitate is filtered off, rinsed with concentrated ammonium hydroxide, then water, and dried. Recrystallization from acetonitrile gave the product (4.5 g), mp 128°-130° C.

Workup

  1. temperatureto warm gradually to room temperature
  2. filtrationAfter one hour the precipitate is filtered off
  3. washrinsed with concentrated ammonium hydroxide
  4. dry with materialwater, and dried
  5. customRecrystallization from acetonitrile

Sources & evidence

ORD record
ord-4f3f6a0967c5498992cec6b0d1d23097
Source dataset
uspto-grants-1983_05
Patent number
US04382939

Reaction notes

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