Hydrochloric Acid → 4,5-Dihydro-2-methyl-8-methylthiothieno[3,4-g]benzoxazole-6-carboxylic acid

HRID 1066223ノート

反応式

HRID 1066223 の反応式
[CH3:1][C:2]1[O:3][C:4]2[C:10]3=[C:11]([S:19][CH3:20])[S:12][C:13]([C:14]([O:16]CC)=[O:15])=[C:9]3[CH2:8][CH2:7][C:5]=2[N:6]=1.C(O)C.[OH-].[Na+].Cl>O.O1CCCC1>[CH3:1][C:2]1[O:3][C:4]2[C:10]3=[C:11]([S:19][CH3:20])[S:12][C:13]([C:14]([OH:16])=[O:15])=[C:9]3[CH2:8][CH2:7][C:5]=2[N:6]=1

参加物

7

反応物 4

HCID 313Hydrochloric AcidHCID 702EthanolHCID 14798Sodium HydroxideHCID 12043502Ethyl 4,5-dihydro-2-methyl-8-methylthiothieno[3,4-g]benzoxazole-6-carboxylate

生成物 1

HCID 120435064,5-Dihydro-2-methyl-8-methylthiothieno[3,4-g]benzoxazole-6-carboxylic acid収率 94.2%

試薬・触媒・溶媒 2

HCID 962Water溶媒HCID 8028Tetrahydrofuran溶媒

反応条件

温度
50 °C

実験手順

Ethyl 4,5-dihydro-2-methyl-8-methylthiothieno[3,4-g]benzoxazole-6-carboxylate (1.88 g) was suspended in a mixed solvent of ethanol (15 ml) and tetrahydrofuran (10 ml); a 2 N aqueous solution of sodium hydroxide (9.1 ml) was added at 50° C. After the reaction mixture was stirred at 50° C. for 2 hours, the solution obtained was poured over water (300 ml), acidified with concentrated hydrochloric acid, and extracted with ethyl acetate-tetrahydrofuran (3:1, v/v). The organic layer was washed with water and dried (MgSO4), after which the solvent was distilled off to yield 4,5-dihydro-2-methyl-8-methylthiothieno[3,4-g]benzoxazole-6-carboxylic acid (1.61 g, 94.2%), which was then recrystallized from chloroform-methanol. Light-yellow prisms. Melting point over 300° C.

後処理

  1. customthe solution obtained
  2. extractionextracted with ethyl acetate-tetrahydrofuran (3:1
  3. washThe organic layer was washed with water
  4. dry with materialdried (MgSO4)
  5. distillationafter which the solvent was distilled off

出典と根拠

ORDレコード
ord-c489e2ffa1c64523ba6c4fb36ba06d49
出典データセット
uspto-grants-2001_06
特許番号
US06242471B1

反応ノート

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