- Sulfur-containing heterocycles derived by reaction of N-thioacylamino alcohols with Lawesson's reagent and saponification of N-thioacylamino esters
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The treatment of 2-N-thioacylamino alcohols (1) with Lawesson's reagent [LR: 2,4-bis(p-methoxyphenyl)-1,3,2,4-dithiaphosphetane 2,4-disulfide] afforded the sulfur-containing heterocycles, 1,3-thiazolines (2) in moderate to good yields, exclusively. The sa
- Nishio, Takehiko,Sekiguchi, Hiroshi
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p. 203 - 212
(2007/10/03)
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- Reaction of (1,ω)-N-Acylamino Alcohols with Lawesson's Reagent: Synthesis of Sulfur-Containing Heterocycles
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Lawesson's reagent [LR: 2,4-bis(p-methoxyphenyl)-1,3,2,4-dithiaphosphetane 2,4-disulfide] is shown to be a valuable reagent for the ready access of sulfur-containing heterocycles: thiazolines 2 starting from the (1,2)-N-acylamino alcohols 1 and benzothiazines 14 from [2-(N-acylamino)phenyl]alkanols 12. Treatment of (1,2)-N-acylamino secondary alcohols 1a-p with LR gave the thiazolines 2a-p via direct conversion of the alcohols to the respective thiols, and the subsequent thionation of the amide carbonyl, followed by cyclization with the elimination of hydrogen sulfide. However, reaction of (1,2)-N-acylamino tertiary alcohols 1q-u with LR yielded the dehydration products 5-7 and 9. Treatment of [2-(N-acylamino)phenyl]alkanols 12a-f with a molar equivalent of LR yielded the 3,1-benzothiazines 14a-f. In this reaction, the [2-(N-acylamino)phenyl]alkanethiols 13a-e were isolated when the corresponding alcohols 12a-e were treated with 0.5 equiv of LR. Further thionation of 13c with LR also gave 3,1-benzothiazine 14c.
- Nishio, Takehiko
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p. 1106 - 1111
(2007/10/03)
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