4-Cyanophenol → 2,2-dimethyl-2H-1-benzopyran-6-carbonitrile

HRID 1885749Notes

Reaction equation

HRID 1885749 reaction equation
[C:1]([C:3]1[CH:8]=[CH:7][C:6]([OH:9])=[CH:5][CH:4]=1)#[N:2].Cl[C:11]([CH3:15])([CH3:14])[C:12]#[CH:13]>C(OCC#C)C#C>[C:1]([C:3]1[CH:4]=[CH:5][C:6]2[O:9][C:11]([CH3:15])([CH3:14])[CH:12]=[CH:13][C:7]=2[CH:8]=1)#[N:2]

Participants

4

Reactant 2

HCID 130194-CyanophenolHCID 706791-Butyne, 3-chloro-3-methyl-

Product 1

HCID 27790742,2-dimethyl-2H-1-benzopyran-6-carbonitrile

Reagents, catalysts & solvents 1

HCID 23349Propargyl etherSolvent

Procedure

According to EPO 0 076 075 describing the possibilities for preparing Kromakalim 4-cyano-phenol of the formula (I) ##STR4## is reacted with 3-chloro-3-methyl-butyne resulting in propargyl-ether of the formula (IX) ##STR5## which is then subjected to ring closure to produce 6-cyano-2,2-dimethyl-2H-1-benzopyran of the formula (III) ##STR6## The compound of the formula (III) is then converted through 6-cyano-trans-3-bromo-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-4-ol to 6-cyano-3,4-dihydro-3,4-epoxy-2,2-dimethyl-2H-1-benzopyran of the formula (V). ##STR7## From the compound of the formula (V) the end-product of the formula (VI) can be obtained by three independent routes.

Sources & evidence

ORD record
ord-88f13fcc82b9429998671f5d129e5036
Source dataset
uspto-grants-1992_09
Patent number
US05145985

Reaction notes

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