Hydrochloric Acid → 2-Methyl-2,3-dihydro-1lambda~6~-naphtho[2,1-e][1,2]thiazine-1,1,4-trione

HRID 1730575Notes

Reaction equation

HRID 1730575 reaction equation
C1O[C:4]2([C:9]3[CH:10]=[CH:11][C:12]4[C:17]([C:8]=3[S:7](=[O:19])(=[O:18])[N:6]([CH3:20])[CH2:5]2)=[CH:16][CH:15]=[CH:14][CH:13]=4)[O:3]C1.Cl>CO>[CH3:20][N:6]1[CH2:5][C:4](=[O:3])[C:9]2[CH:10]=[CH:11][C:12]3[C:17]([C:8]=2[S:7]1(=[O:18])=[O:19])=[CH:16][CH:15]=[CH:14][CH:13]=3

Participants

4

Reactant 2

HCID 313Hydrochloric AcidHCID 86734202HCID 86734202, compound

Product 1

HCID 214980942-Methyl-2,3-dihydro-1lambda~6~-naphtho[2,1-e][1,2]thiazine-1,1,4-trione

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A suspension of 10.7 gm (0.35 mol) of 2-methyl-2H-naphtho[2,1-e]-1,2-thiazine-4(3H)-one-1,1-dioxide-ethylene ketal in 200 ml of methanol and 200 ml of aqueous 9% hydrochloric acid wasrefluxed for 30 minutes. Then, the mixture was evaporated to dryness in vacuo, the residue was taken up in methylene chloride, and the solution wsneutralized and again evaporated to dryness. After recrystallization of theresidue from ethanol, 6.3 gm (69% of theory) of 2-methyl-2H-naphtho[2,1-e]-1,2-thiazine-4(3H)-one-1,1-dioxide, m.p. 192°-193° C), were obtained.

Workup

  1. customThen, the mixture was evaporated to dryness in vacuo
  2. customagain evaporated to dryness
  3. customAfter recrystallization of theresidue from ethanol, 6.3 gm (69% of theory) of 2-methyl-2H-naphtho[2,1-e]-1,2-thiazine-4(3H)-one-1,1-dioxide, m.p. 192°-193° C),
  4. customwere obtained

Sources & evidence

ORD record
ord-ea0d920ac25d4dd58e07bfcfdca2285f
Source dataset
uspto-grants-1976_11
Patent number
US03992535

Reaction notes

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