Methyl Isobutyl Ketone → 7-[2-[4-(diphenylmethylene)-1-piperidinyl]ethyl]-3,4-dihydro-8-methyl-2H,6H-pyrimido[2,1-b][1,3]-thiazin-6-one

HRID 1380258Notes

Reaction equation

HRID 1380258 reaction equation
Br.Br[CH2:3][CH2:4][C:5]1[C:14](=[O:15])[N:13]2[C:8]([S:9][CH2:10][CH2:11][CH2:12]2)=[N:7][C:6]=1[CH3:16].Br.[C:18]1([C:24]([C:31]2[CH:36]=[CH:35][CH:34]=[CH:33][CH:32]=2)=[C:25]2[CH2:30][CH2:29][NH:28][CH2:27][CH2:26]2)[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1.C(=O)([O-])[O-].[Na+].[Na+].CC(C)CC(=O)C>O>[C:18]1([C:24]([C:31]2[CH:36]=[CH:35][CH:34]=[CH:33][CH:32]=2)=[C:25]2[CH2:26][CH2:27][N:28]([CH2:3][CH2:4][C:5]3[C:14](=[O:15])[N:13]4[C:8]([S:9][CH2:10][CH2:11][CH2:12]4)=[N:7][C:6]=3[CH3:16])[CH2:29][CH2:30]2)[CH:19]=[CH:20][CH:21]=[CH:22][CH:23]=1

Participants

6

Reactant 4

HCID 7909Methyl Isobutyl KetoneHCID 10340Sodium CarbonateHCID 155864667-(2-bromoethyl)-3,4-dihydro-8-methyl-2H,6H-pyrimido[2,1-b][1,3]thiazin-6-one monohydrobromideHCID 233260664-(Diphenylmethylene)piperidine hydrobromide

Product 1

HCID 133632517-[2-[4-(diphenylmethylene)-1-piperidinyl]ethyl]-3,4-dihydro-8-methyl-2H,6H-pyrimido[2,1-b][1,3]-thiazin-6-oneYield 60%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of 7.4 parts of 7-(2-bromoethyl)-3,4-dihydro-8-methyl-2H, 6H-pyrimido[2,1-b][1,3]thiazin-6-one monohydrobromide, 6.6 parts of 4-(diphenylmethylene)piperidine hydrobromide, 12 parts of sodium carbonate and 120 parts of 4-methyl-2-pentanone was stirred and refluxed overnight. The reaction mixture was cooled, water was added and the layers were separated. The organic phase was dried, filtered and evaporated. The residue was purified by column-chromatography over silica gel using a mixture of trichloromethane and methanol (95:5 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was crystallized from a mixture of 4-methyl-2-pentanone and 2,2'-oxybispropane. The product was filtered off and recrystallized from 2-propanol, yielding 5.5 parts (60%) of 7-[2-[4-(diphenylmethylene)-1-piperidinyl]ethyl]-3,4-dihydro-8-methyl-2H,6H-pyrimido[2,1-b][1,3]-thiazin-6-one; mp. 176.0° C. (compound 104).

Workup

  1. temperaturerefluxed overnight
  2. temperatureThe reaction mixture was cooled
  3. customthe layers were separated
  4. customThe organic phase was dried
  5. filtrationfiltered
  6. customevaporated
  7. customThe residue was purified by column-chromatography over silica gel using
  8. additiona mixture of trichloromethane and methanol (95:5 by volume) as eluent
  9. customThe pure fractions were collected
  10. customthe eluent was evaporated
  11. customThe residue was crystallized from a mixture of 4-methyl-2-pentanone and 2,2'-oxybispropane
  12. filtrationThe product was filtered off
  13. customrecrystallized from 2-propanol

Sources & evidence

ORD record
ord-bb2df499e4324b78aa55190ab9435f22
Source dataset
uspto-grants-1986_04
Patent number
US04581171

Reaction notes

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