Nitric Acid → 5-amino-6-fluorobenzo[d]thiazol-2(3H)-one

HRID 1199620

反応式

HRID 1199620 の反応式
[F:1][C:2]1[CH:11]=[CH:10][C:5]2[NH:6][C:7](=[O:9])[S:8][C:4]=2[CH:3]=1.[N+:12]([O-])(O)=O>S(=O)(=O)(O)O.[Fe]>[NH2:12][C:11]1[C:2]([F:1])=[CH:3][C:4]2[S:8][C:7](=[O:9])[NH:6][C:5]=2[CH:10]=1

参加物

5

反応物 2

HCID 944Nitric AcidHCID 446672-Benzothiazolinone, 6-fluoro-

生成物 1

HCID 144586855-amino-6-fluorobenzo[d]thiazol-2(3H)-one

試薬・触媒・溶媒 2

HCID 23925Iron触媒HCID 1118Sulfuric Acid溶媒

実験手順

6-fluoro-2(3H)-benzothiazolone (82.9 g) was nitrated in conc. sulfuric acid (800 g) with a 98% nitric acid (5% excess of the theoretical amount) at a temperature of 0° to 5° C. under stirring for 1.5 hours. The reaction mixture was poured into ice water and filtered. The solid material separated by the filtration was dried, and recrystallized from acetone, so that 6-fluoro-5-nitro-2(3H)-benzothiazolone (67.7 g) was obtained. The purity of this compound was 92% (this purity was determined by HPLC). The whole amount of this compound was reduced with iron powder to obtain 5-amino-6-fluoro-2(3H)-benzothiazolone (52.4 g). 4 g of the amino compound were subjected to an alkylation operation with the aid of 3-chloromethyl-5-methyl-1,2,4-oxadiazole (2.9 g), in acetonitrile (100 ml) in the presence of potassium carbonate (3 g) as the dehydrochlorinating agent. This operation was carried out under reflux for 2 hours, so that the aimed compound, i.e. 5-amino-6-fluoro-3-(5-methyl-1,2,4-oxadiazol-3-ylmethyl)-2(3H)-benzothiazolone (5.3 g) was obtained. m.p. 156°-157° C.

後処理

  1. customat a temperature of 0° to 5° C.
  2. filtrationfiltered
  3. customThe solid material separated by the filtration
  4. customwas dried
  5. customrecrystallized from acetone, so that 6-fluoro-5-nitro-2(3H)-benzothiazolone (67.7 g)
  6. customwas obtained

出典と根拠

ORDレコード
ord-1ce050e39e3d4b6b893d0ddea66e5756
出典データセット
uspto-grants-1990_02
特許番号
US04902335

関連ノート

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