Acetic Anhydride → trans-3-acetoxy-4-(2-cyanoiminothiazolidin-3-yl)-2,2-diethyl-3,4-dihydro-2H-1-benzopyran-6-carbonitrile

HRID 704801Notes

Reaction equation

HRID 704801 reaction equation
[C:1]([N:3]=[C:4]1[N:8]([C@@H:9]2[C:14]3[CH:15]=[C:16]([C:19]#[N:20])[CH:17]=[CH:18][C:13]=3[O:12][C:11]([CH2:23][CH3:24])([CH2:21][CH3:22])[C@H:10]2[OH:25])[CH2:7][CH2:6][S:5]1)#[N:2].[C:26](OC(=O)C)(=[O:28])[CH3:27]>N1C=CC=CC=1.C(OCC)(=O)C>[C:26]([O:25][C@H:10]1[C@H:9]([N:8]2[CH2:7][CH2:6][S:5][C:4]2=[N:3][C:1]#[N:2])[C:14]2[CH:15]=[C:16]([C:19]#[N:20])[CH:17]=[CH:18][C:13]=2[O:12][C:11]1([CH2:23][CH3:24])[CH2:21][CH3:22])(=[O:28])[CH3:27]

Participants

5

Reactant 2

HCID 7918Acetic AnhydrideHCID 86744550trans-4-(2-cyanoiminothiazolidin-3-yl)-2,2-diethyl-3,4-dihydro-3-hydroxy-2H-1-benzopyran-6carbonitrile

Product 1

HCID 86744551trans-3-acetoxy-4-(2-cyanoiminothiazolidin-3-yl)-2,2-diethyl-3,4-dihydro-2H-1-benzopyran-6-carbonitrile

Reagents, catalysts & solvents 2

HCID 1049PyridineSolventHCID 8857Ethyl AcetateSolvent

Procedure

A mixture of trans-4-(2-cyanoiminothiazolidin-3-yl)-2,2-diethyl-3,4-dihydro-3-hydroxy-2H-1-benzopyran-6carbonitrile -(0.28 g) and acetic anhydride (0.15 ml) in pyridine (1.4 ml) was stirred overnight at ambient temperature. The reaction mixture was diluted with ethyl acetate, and then washed with 5% aqueous hydrochloric acid, saturated sodium bicarbonate solution and brine successively. The extract was dried over anhydrous magnesium sulfate and evaporated in vacuo to give a residue of trans-3-acetoxy-4-(2-cyanoiminothiazolidin-3-yl)-2,2-diethyl-3,4-dihydro-2H-1-benzopyran-6-carbonitrile, which was dissolved in toluene (12.5 ml) and thereto was added 1,8-diazabicyclo[5.4.0]undec-7-ene (0.35 ml). The reaction mixture was heated at 100° C. with stirring for an hour and 40 minutes. The solvent was evaporated in vacuo. The residue was triturated with ethyl acetate and recrystallized from 85% aqueous acetonitrile to give 4-(2-cyanoiminothiazolidin-3-yl)-2,2-diethyl-2H-1-benzopyran-6-carbonitrile (0.18 g).

Workup

  1. washwashed with 5% aqueous hydrochloric acid, saturated sodium bicarbonate solution and brine successively
  2. dry with materialThe extract was dried over anhydrous magnesium sulfate
  3. customevaporated in vacuo

Sources & evidence

ORD record
ord-95bfacaec0ae4462a9685043091fcfa3
Source dataset
uspto-grants-1991_01
Patent number
US04988723

Reaction notes

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