Pyridine → HCID 23050251, compound

HRID 1651628Notes

Reaction equation

HRID 1651628 reaction equation
[CH3:1][O:2][C:3]1[C:14]([O:15][CH3:16])=[CH:13][C:6]2[S:7][C:8]([C:10](O)=[O:11])=[CH:9][C:5]=2[CH:4]=1.C1(C)C=CC=CC=1.S(Cl)(Cl)=O.[N:28]1C=CC=CC=1>>[CH3:1][O:2][C:3]1[C:14]([O:15][CH3:16])=[CH:13][C:6]2[S:7][C:8]([C:10]([NH2:28])=[O:11])=[CH:9][C:5]=2[CH:4]=1

Participants

5

Reactant 4

HCID 1049PyridineHCID 1140TolueneHCID 24386Thionyl ChlorideHCID 2686205,6-dimethoxy-1-benzothiophene-2-carboxylic acid

Product 1

HCID 23050251HCID 23050251, compound

Procedure

A mixture of 5,6-dimethoxy-benzo[b]thiophene-2-carboxylic acid (68.8 g), dry toluene (350 ml), thionyl chloride (126 ml) and pyridine (1.75 ml) was stirred and heated at reflux for 4 hours. The resultant mixture was cooled, evaporated to dryness under vacuum and the residue was purged with dry toluene (3×250 ml). The resulting crude acid chloride was suspended in dioxan (160 ml) then cooled in an ice bath and treated in one portion with concentrated ammonium hydroxide solution (33% w/w, 900 ml). This gave a suspension of brown solid which was stirred for two hours then filtered, washed with water and dried under vacuum over calcium chloride at 60° C. to give 5,6-dimethoxy-benzo[b]thiophene-2-carboxamide (62.5 g), m.p. 211°-213° C.

Workup

  1. temperatureheated
  2. temperatureat reflux for 4 hours
  3. customevaporated to dryness under vacuum
  4. customthe residue was purged with dry toluene (3×250 ml)
  5. temperaturethen cooled in an ice bath
  6. additiontreated in one portion with concentrated ammonium hydroxide solution (33% w/w, 900 ml)
  7. customThis gave
  8. additiona suspension of brown solid which
  9. stirringwas stirred for two hours
  10. filtrationthen filtered
  11. washwashed with water
  12. dry with materialdried under vacuum over calcium chloride at 60° C.

Sources & evidence

ORD record
ord-f6609f871fd14fd5b84bfacd832f5eb3
Source dataset
uspto-grants-1990_05
Patent number
US04929636

Reaction notes

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