Sodium → 3,4-dihydro-2H-[1,3]oxazino[3,2-a]benzimidazole

HRID 46866Notes

Reaction equation

HRID 46866 reaction equation
[Na].CS(O)(=O)=O.O[CH2:8][CH2:9][CH2:10][N:11]1[C:15]2[CH:16]=[CH:17][CH:18]=[CH:19][C:14]=2[NH:13][C:12]1=[O:20]>C(O)C>[O:20]1[C:12]2=[N:13][C:14]3[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=3[N:11]2[CH2:10][CH2:9][CH2:8]1

Participants

4

Reactant 2

HCID 5360545SodiumHCID 867353601,3-dihydro-1-(3-hydroxypropyl)-2H-benzimidazol-2-one methanesulfonate

Product 1

HCID 110951143,4-dihydro-2H-[1,3]oxazino[3,2-a]benzimidazole

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a solution of 0.5 parts of sodium in 40 parts of absolute ethanol are added in the cold 5.4 parts of 1,3-dihydro-1-(3-hydroxypropyl)-2H-benzimidazol-2-one methanesulfonate. The whole is stirred until all solid enters solution. The solution is further stirred and refluxed for 2 hours. After cooling the reaction mixture is filtered from some inorganic matter and the filtrate is evaporated. The residue is dissolved in 80 parts of methylbenzene, boiled with activated charcoal, filtered and the filtrate is evaporated again. The solid residue is washed with cold methylbenzene and crystallized from 16 parts of methylbenzene, yielding 2.6 parts of 3,4-dihydro-2H-[1,3]oxazino[3,2-a]benzimidazole; mp. 116.5°-118.5° C.

Workup

  1. stirringThe solution is further stirred
  2. temperaturerefluxed for 2 hours
  3. temperatureAfter cooling the reaction mixture
  4. filtrationis filtered from some inorganic matter
  5. customthe filtrate is evaporated
  6. dissolutionThe residue is dissolved in 80 parts of methylbenzene
  7. filtrationfiltered
  8. customthe filtrate is evaporated again
  9. washThe solid residue is washed with cold methylbenzene
  10. customcrystallized from 16 parts of methylbenzene

Sources & evidence

ORD record
ord-7a611e3a8b2a4244b930aae757826585
Source dataset
uspto-grants-1979_11
Patent number
US04175129

Reaction notes

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