Triethylamine → (E)-3-(2,3-dihydrobenzo[b][1,4]dioxin-5-yl)acryloyl azide

HRID 1852060Notes

Reaction equation

HRID 1852060 reaction equation
[O:1]1[CH2:6][CH2:5][O:4][C:3]2[C:7](/[CH:11]=[CH:12]/[C:13]([OH:15])=O)=[CH:8][CH:9]=[CH:10][C:2]1=2.C1(P([N:30]=[N+:31]=[N-:32])(C2C=CC=CC=2)=O)C=CC=CC=1.CCN(CC)CC>C1C=CC=CC=1>[O:1]1[CH2:6][CH2:5][O:4][C:3]2[C:7](/[CH:11]=[CH:12]/[C:13]([N:30]=[N+:31]=[N-:32])=[O:15])=[CH:8][CH:9]=[CH:10][C:2]1=2

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 199401P,P-Diphenylphosphinic azideHCID 5343159(E)-3-(2,3-dihydrobenzo[b][1,4]dioxin-5-yl)acrylic acid

Product 1

HCID 86683170(E)-3-(2,3-dihydrobenzo[b][1,4]dioxin-5-yl)acryloyl azideYield 84.5%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

(E)-3-(2,3-dihydrobenzo[b][1,4]dioxin-5-yl)acrylic acid (5 g, 24.25 mmol), diphenylphosphoryl azide (4.96 mL, 23.04 mmol), and Et3N (6.76 mL, 48.5 mmol) were dissolved in benzene and stirred for 16 h. The solution was concentrated under vacuum and the residue was purified by silica gel chromatography using 20% EtOAc/Hexanes to give 4.5 g of (E)-3-(2,3-dihydrobenzo[b][1,4]dioxin-5-yl)acryloyl azide as a yellow solid, which was taken into PhCH2Ph (50 mL). The resulting solution was slowly heated to 80° C. for 1 h and then to reflux for 3 h. After cooling to rt, the solid was collected washing with benzene to give 3.5 g of the desired product 2,3-dihydro-[1,4]dioxino[2,3-f]isoquinolin-7-ol as a solid. 1H NMR (400 MHz, CD3OD) δ ppm 4.37 (m, 4H), 6.83 (d, J=7.09 Hz, 1H), 7.02 (d, J=8.80 Hz, 1H), 7.12 (d, J=7.34 Hz, 1H), 7.79 (d, J=8.80 Hz, 1H); MS: (M+H)+ 204.

Workup

  1. concentrationThe solution was concentrated under vacuum
  2. customthe residue was purified by silica gel chromatography

Sources & evidence

ORD record
ord-f4bfd13f1eab46d4a6d799a38b10c652
Source dataset
uspto-grants-2015_02
Patent number
US08957203B2

Reaction notes

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