Propargyl bromide → N-propargyl-4-amino-2,2-difluorobenzo-1,3-dioxole

HRID 1276043Notes

Reaction equation

HRID 1276043 reaction equation
[CH2:1](Br)[C:2]#[CH:3].[NH2:5][C:6]1[C:14]2[O:13][C:12]([F:16])([F:15])[O:11][C:10]=2[CH:9]=[CH:8][CH:7]=1>C1(C)C=CC=CC=1>[CH2:1]([NH:5][C:6]1[C:14]2[O:13][C:12]([F:16])([F:15])[O:11][C:10]=2[CH:9]=[CH:8][CH:7]=1)[C:2]#[CH:3]

Participants

4

Reactant 2

HCID 7842Propargyl bromideHCID 27368912,2-Difluoro-1,3-dioxaindan-4-amine

Product 1

HCID 10910826N-propargyl-4-amino-2,2-difluorobenzo-1,3-dioxoleYield 44%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent2×

Procedure

At 20-25° C., 53.3 g of an 80% strength solution of propargyl bromide in toluene (=0.36 mol of propargyl bromide) are added dropwise to a solution of 120 g (0.67 mol) of 4-amino-2,2-difluorobenzo-1,3-dioxole in 150 ml of toluene. After 2 hours at 80° C., the reaction mixture is cooled to room temperature and the precipitate is filtered off with suction and washed with n-hexane. The filtrate is concentrated under reduced pressure and the residue is purified over silica gel using cyclohexane/ethyl acetate mixtures and then-crystallized from pentane. 33.2 g (44% of theory) of N-propargyl-4-amino-2,2-difluorobenzo-1,3-dioxole of mp.: 66-68° C. are obtained in this manner. NMR: (CDCl3): 2.25 (t, 1H); 3.9 (2*s, 3H); 6.30 (dd, 1H); 6.50 (d, 1H); 6.85 (d, 1H)

Workup

  1. filtrationthe precipitate is filtered off with suction
  2. washwashed with n-hexane
  3. concentrationThe filtrate is concentrated under reduced pressure
  4. customthe residue is purified over silica gel
  5. customthen-crystallized from pentane

Sources & evidence

ORD record
ord-1f1db1c788fc4a13994acbd1f0e63e6d
Source dataset
uspto-grants-2000_12
Patent number
US06165943

Reaction notes

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