2,2-Dimethyl-3,4-epoxy-6-cyanochroman → trans-4-(2-cyanoiminothiazolidin-3-yl)-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-1-benzopyran-6-carbonitrile

HRID 704793Notes

Reaction equation

[O:1]1[CH:7]2[CH:2]1[C:3]([CH3:15])([CH3:14])[O:4][C:5]1[CH:11]=[CH:10][C:9]([C:12]#[N:13])=[CH:8][C:6]=12.[C:16]([N:18]=[C:19]1[NH:23][CH2:22][CH2:21][S:20]1)#[N:17]>N1C=CC=CC=1>[C:16]([N:18]=[C:19]1[N:23]([C@@H:7]2[C:6]3[CH:8]=[C:9]([C:12]#[N:13])[CH:10]=[CH:11][C:5]=3[O:4][C:3]([CH3:15])([CH3:14])[C@H:2]2[OH:1])[CH2:22][CH2:21][S:20]1)#[N:17]

Participants

Conditions

Temperature: 100 °C

Procedure

A mixture of 3,4-epoxy-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-6-carbonitrile (0.51 g), 2-cyanoiminothiazolidine (0.64 g) and pyridine (4.1 ml) was heated at 100° C. for 1.5 hours. Pyridine was removed under reduced pressure. The residue was diluted with ethyl acetate (20 ml). The solution was washed with water (20 ml and 15 ml), 5% aqueous hydrochloric acid (15 ml×2) and saturated aqueous sodium chloride (15 ml) successively, treated with charcoal, and then dried over anhydrous magnesium sulfate. The solvent was evaporated in vacuo, and the residue was triturated with ethyl acetate, to give trans-4-(2-cyanoiminothiazolidin-3-yl)-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-1-benzopyran-6-carbonitrile (0.47 g).

Workup

customPyridine was removed under reduced pressure
additionThe residue was diluted with ethyl acetate (20 ml)
washThe solution was washed with water (20 ml and 15 ml), 5% aqueous hydrochloric acid (15 ml×2) and saturated aqueous sodium chloride (15 ml) successively
additiontreated with charcoal
dry with materialdried over anhydrous magnesium sulfate
customThe solvent was evaporated in vacuo
customthe residue was triturated with ethyl acetate

Sources & evidence

ORD record: ord-35add201ea574317bb7bb3b5a14aa129
Source dataset: uspto-grants-1991_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04988723

Reaction notes

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