Triethyl phosphite → 2-Benzothiazolecarboxylic acid, 7-nitro-5-(trifluoromethyl)-, ethyl ester

HRID 879983Notes

Reaction equation

HRID 879983 reaction equation
[N+:1]([C:4]1[C:12]2[S:11][C:10]([C:13]([O:15][CH2:16][CH3:17])=[O:14])=[N+:9]([O-])[C:8]=2[CH:7]=[C:6]([C:19]([F:22])([F:21])[F:20])[CH:5]=1)([O-:3])=[O:2].P(OCC)(OCC)OCC>C(O)C>[N+:1]([C:4]1[C:12]2[S:11][C:10]([C:13]([O:15][CH2:16][CH3:17])=[O:14])=[N:9][C:8]=2[CH:7]=[C:6]([C:19]([F:22])([F:21])[F:20])[CH:5]=1)([O-:3])=[O:2]

Participants

4

Reactant 2

HCID 31215Triethyl phosphiteHCID 2779933HCID 2779933, compound

Product 1

HCID 848200762-Benzothiazolecarboxylic acid, 7-nitro-5-(trifluoromethyl)-, ethyl ester

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A suspension of 20 g (59.48 mmol) of ethyl 7-nitro-5-(trifluoromethyl)-1,3-benzothiazole-2-carboxylate-3-oxide, the synthesis of which is carried out according to a process already described in the literature (K. Wagner et al.; Chem. Ber. 106, 640-654, 1973), in 300 ml of ethanol is stirred at AT. After the addition, dropwise, of 11.22 ml (65.43 mmol) of triethyl phosphite, the reaction mixture is stirred at 70° C. for 2 hours, during which time it becomes homogeneous and yellow. Silica is then added thereto and the solvent is evaporated off under reduced pressure. The powder obtained is loaded onto a silica column. The purification is carried out using a cyclohexane/ethyl acetate mixture. The fractions of pure product are evaporated and the residue is taken up with petroleum ether, filtered, and then rinsed with a minimum amount of ethyl ether. After drying at 40° C., under reduced pressure, 16.98 g of expected compound are obtained.

Workup

  1. customthe synthesis of which
  2. additionAfter the addition
  3. additionSilica is then added
  4. customthe solvent is evaporated off under reduced pressure
  5. customThe powder obtained
  6. customThe purification
  7. customThe fractions of pure product are evaporated
  8. filtrationfiltered
  9. washrinsed with a minimum amount of ethyl ether
  10. dry with materialAfter drying at 40° C., under reduced pressure, 16.98 g of expected compound
  11. customare obtained

Sources & evidence

ORD record
ord-214c8316318f431fae2f4be625f051db
Source dataset
uspto-grants-2015_03
Patent number
US08993561B2

Reaction notes

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