p-Toluenesulfonic acid → 2-Ethyl-4-(pyrrolidin-1-yl)-1lambda~6~-naphtho[2,1-e][1,2]thiazine-1,1(2H)-dione

HRID 1730583Notes

Reaction equation

HRID 1730583 reaction equation
[CH2:1]([N:3]1[CH2:8][C:7](=O)[C:6]2[CH:10]=[CH:11][C:12]3[C:17]([C:5]=2[S:4]1(=[O:19])=[O:18])=[CH:16][CH:15]=[CH:14][CH:13]=3)[CH3:2].[NH:20]1[CH2:24][CH2:23][CH2:22][CH2:21]1.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1C=CC=CC=1>[CH2:1]([N:3]1[CH:8]=[C:7]([N:20]2[CH2:24][CH2:23][CH2:22][CH2:21]2)[C:6]2[CH:10]=[CH:11][C:12]3[C:17]([C:5]=2[S:4]1(=[O:19])=[O:18])=[CH:16][CH:15]=[CH:14][CH:13]=3)[CH3:2]

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acid2×HCID 31268Pyrrolidine2×HCID 214980992-Ethyl-2,3-dihydro-1lambda~6~-naphtho[2,1-e][1,2]thiazine-1,1,4-trione

Product 1

HCID 214980972-Ethyl-4-(pyrrolidin-1-yl)-1lambda~6~-naphtho[2,1-e][1,2]thiazine-1,1(2H)-dioneYield 50.1%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

A mixture of 2 gm (7.3 millimols) of 2-ethyl-2H-naphtho[2,1-e]-1,2-thiazine-4(3H)-one-1,1-dioxide, 1.04 gm (14.6 millimols) of pyrrolidine, 200 mgm p-toluenesulfonic acid and 100 mlof benzene was refluxed for 24 hours in a vessel equipped with a water trap. Subsequently, another 1.04 gm (14.6 millimols) of pyrrolidine and 200 mgm of p-toluenesulfonic acid were added, and the reaction mixture wasrefluxed for 24 hours more. After cooling, the reaction mixture was evaporated, and the residue was extracted with ether several times. The combined ether extracts were washed twice with water, dried and evaporated. Recrystallization of the residue from methanol yielded 1.2 g (50% of theory) of the desired enamine, m.p. 115°-117° C.

Workup

  1. temperaturewas refluxed for 24 hours in a vessel
  2. customequipped with a water trap
  3. temperatureAfter cooling
  4. customthe reaction mixture was evaporated
  5. extractionthe residue was extracted with ether several times
  6. washThe combined ether extracts were washed twice with water
  7. customdried
  8. customevaporated
  9. customRecrystallization of the residue from methanol

Sources & evidence

ORD record
ord-17d3479787284bf9a6ceb13f52beaa7a
Source dataset
uspto-grants-1976_11
Patent number
US03992535

Reaction notes

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