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

HRID 1957429Notes

Reaction equation

HRID 1957429 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-0539b57fa5de469a99a3dc5ea50b2f86
Source dataset
uspto-grants-1998_07
Patent number
US05783589

Reaction notes

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