Methyl iodide → 4-hydroxy-2-methyl-2H-naphtho[2,1-e]-1,2-thiazine-3-carboxylic acid methylester-1,1-dioxide

HRID 1730533Notes

Reaction equation

HRID 1730533 reaction equation
[OH-].[Na+].[CH3:3][O:4][C:5]([C:7]1[NH:8][S:9](=[O:23])(=[O:22])[C:10]2[C:21]3[C:16](=[CH:17][CH:18]=[CH:19][CH:20]=3)[CH:15]=[CH:14][C:11]=2[C:12]=1[OH:13])=[O:6].[CH3:24]I>O.CO>[CH3:3][O:4][C:5]([C:7]1[N:8]([CH3:24])[S:9](=[O:23])(=[O:22])[C:10]2[C:21]3[C:16](=[CH:17][CH:18]=[CH:19][CH:20]=3)[CH:15]=[CH:14][C:11]=2[C:12]=1[OH:13])=[O:6]

Participants

6

Reactant 3

HCID 6328Methyl iodideHCID 14798Sodium HydroxideHCID 547193904-hydroxy-2H-naphtho[2,1-e]-1,2thiazine-3-carboxylic acid methyl ester-1,1-dioxide

Product 1

HCID 546906514-hydroxy-2-methyl-2H-naphtho[2,1-e]-1,2-thiazine-3-carboxylic acid methylester-1,1-dioxideYield 85%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Conditions

Temperature
40 °C

Procedure

A solution of 8.2 gm (0.205 mol) of sodium hydroxide in 200 ml of water wasadded dropwise over a period of 40 minutes at a reaction temperature of 20°-25° C to a suspension of 61.0 gm (0.2 mol) of 4-hydroxy-2H-naphtho[2,1-e]-1,2-thiazine-3-carboxylic acid methyl ester-1,1-dioxide and 85.1 gm (0.6 mol) of methyl iodide in 500 ml of methanol. After stirring it for 4 hours, the mixture was cooled to +5° C, and the precipitate (= 50 gm of crude product) was suction-filtered off and washed with ice-cold methanol. The combined methanolic solutions were heated at 40° C for 15 minutes and then evaporated in vacuo until onset of crystallization. An additional 9 gm of crude product were obtained by suctionfiltration and washing with ice-coldmethanol. Recrystallization of the combined crude products from ethylene chloride yielded 53.3 gm (85% of theory) of 4 -hydroxy-2-methyl-2H-naphtho[2,1-e]-1,2-thiazine-3-carboxylic acid methyl ester-1,1-dioxide, m.p. 229°-230° C.

Workup

  1. temperaturethe mixture was cooled to +5° C
  2. filtrationthe precipitate (= 50 gm of crude product) was suction-filtered off
  3. washwashed with ice-cold methanol
  4. customevaporated in vacuo until onset of crystallization
  5. customAn additional 9 gm of crude product were obtained by suctionfiltration
  6. washwashing with ice-coldmethanol
  7. customRecrystallization of the combined crude products from ethylene chloride

Sources & evidence

ORD record
ord-bc08bd5a4a77466096874200220ab227
Source dataset
uspto-grants-1976_11
Patent number
US03992535

Reaction notes

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