Synthesis of Green Colored Photochromic 6′-Arylamino Spiro [2H]Naphth[1,2-b]oxazines

Abstract

The published route to a series of 6′-arylamino substituted photochromic spirooxazines has been investigated with improvements made to perform the synthesis in satisfactory yield. The route has been exemplified with several novel derivatives prepared (including hydroxyl functionalised). Additionally, a one-pot procedure for the conversion of suitably functionalized 1,2-naphthoquinones into the photochromic compounds is reported.

Keywords:

• Photochromic
• photochromism
• spirooxazine

ACKNOWLEDGMENTS

The authors thank the Co-operative Research Centre for Polymers and CSIRO Molecular and Health Technologies for their support.

Notes

^a Isolated yield.

^b Reaction performed at room temperature for 24 h followed by chromatographic purification.

^c Reaction performed at 60 °C for 18 h followed by precipitation.

^a Isolated yield.

^b Reaction performed at reflux for 22 h followed by chromatographic purification.

^c Reaction performed at 100 °C in a sealed tube for 3 h followed by chromatographic purification.

^d Reaction performed at 100 °C in a sealed tube for 3 h followed by precipitation.

^a Isolated yield.

^b 6a (1 eq.) and NH₃OH.Cl (1.1 eq.) were stirred at RT for 1 h. 8b (1.3 eq.) and additive added, then the mixture was heated as indicated.

^c 6a (1 eq.), 8a (1.3 eq.), NH₃OH.Cl (1.1 eq.) and additive were stirred at RT for 1 h, then the mixture was heated as indicated.

^d 6a (1 eq.), NH₃OH.Cl (1.1 eq.) and additive were stirred at RT for 1 h. 8b (1.3 eq.) added, then the mixture was heated as indicated.

^e As ^b but 6b used as starting material to yield 9c.

^f As ^b but 6c used as starting material to yield 9d.