Formaldehyde → 2-(Chloromethyl)-4-isopropyl-6-methoxybenzo[D]isothiazol-3(2H)-one 1,1-dioxide

HRID 864735Notes

Reaction equation

HRID 864735 reaction equation
[CH2:1]=[O:2].Cl[Si](C)(C)C.[Sn](Cl)(Cl)(Cl)[Cl:9].[CH:13]([C:16]1[CH:26]=[C:25]([O:27][CH3:28])[CH:24]=[C:23]2[C:17]=1[C:18](=O)[NH:19][S:20]2(=[O:22])=[O:21])([CH3:15])[CH3:14]>ClCCCl.O>[Cl:9][CH2:18][N:19]1[C:1](=[O:2])[C:17]2[C:23](=[CH:24][C:25]([O:27][CH3:28])=[CH:26][C:16]=2[CH:13]([CH3:15])[CH3:14])[S:20]1(=[O:22])=[O:21]

Participants

7

Reactant 4

HCID 712FormaldehydeHCID 6397ChlorotrimethylsilaneHCID 24287Tin tetrachlorideHCID 101473624-Isopropyl-6-methoxysaccharin

Product 1

HCID 99951732-(Chloromethyl)-4-isopropyl-6-methoxybenzo[D]isothiazol-3(2H)-one 1,1-dioxideYield 87%

Reagents, catalysts & solvents 2

HCID 111,2-DichloroethaneSolventHCID 962WaterSolvent

Procedure

To a suspension of 24 g of paraformaldehyde (0.8 mole) and 86.4 g of chlorotrimethylsilane (1.6 moles) in 200 mL of 1,2-dichloroethane was added 0.8 ml anhydrous tin(IV) chloride and the resulting solution stirred on a steam bath for one hour. At the end of this period, 51 g of 4-isopropyl-6-methoxysaccharin (0.2 mole) was added to the clear solution and the reaction mixture was further refluxed for 18 hours. It was cooled to room temperature, poured into water, the organic layer separated and washed with 50 mL of 2N sodium hydroxide solution. The organic layer was dried over anhydrous magnesium sulfate and concentrated under vacuum to give crude product. It was purified by crystallization from ethyl acetate/hexane to give 57 g (87%) of 2-chloromethyl-4-isopropyl-6-methoxysaccharin, mp 151° C.

Workup

  1. temperaturethe reaction mixture was further refluxed for 18 hours
  2. customthe organic layer separated
  3. washwashed with 50 mL of 2N sodium hydroxide solution
  4. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
  5. concentrationconcentrated under vacuum
  6. customto give crude product
  7. customIt was purified by crystallization from ethyl acetate/hexane

Sources & evidence

ORD record
ord-17b20e949975444ba80c1eb20b2ef3dd
Source dataset
uspto-grants-1996_10
Patent number
US05563163

Reaction notes

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