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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: PRAGATI1 on February 07, 2018, 04:57:16 AM

Title: how to add chromophore group in cyclo hexane amine and cyclo hexane alchohole?
Post by: PRAGATI1 on February 07, 2018, 04:57:16 AM

What can be added to cyclohexane amine or alchohol as a chromophoric group?

Title: Re: how to add chromophore group in cyclo hexane amine and cyclo hexane alchohole?
Post by: pgk on February 08, 2018, 12:27:13 PM

Amidation or esterification with 4-methoxycinnamic acid, respectively that lead to a strong UV absorption at ≈ 300 nm.

Title: Re: how to add chromophore group in cyclo hexane amine and cyclo hexane alchohole?
Post by: PRAGATI1 on February 09, 2018, 12:11:59 AM

do i need to give heat? i want to add chromophore group at RT or by vortexing?

Title: Re: how to add chromophore group in cyclo hexane amine and cyclo hexane alchohole?
Post by: pgk on February 09, 2018, 10:14:50 AM

1). Yes, you need to heat.
2). If you do not want to heat, just dissolve your amine or your alcohol with benzoic anhydride in dichloromethane, at 1/1.1 molar ratio and “vortex” it for 2 h at room temperature and then add aqueous NaOH or aqueous KOH at 1.5 molar ratio and shake it for a few minutes. The organic phase (the bottom layer) contains the benzoate derivative, which absorbs at ≈ 270-280 nm.
Hint: wear safety glasses, while working and take care of possibly exothermic reactions.   

Title: Re: how to add chromophore group in cyclo hexane amine and cyclo hexane alchohole?
Post by: wildfyr on February 09, 2018, 04:02:29 PM

For the cyclohexylamine, a huge variety of dyes come as NHS esters. They will react almost immediately and quantitatively with amines at room temperature, and can be separated by simple liquid/liquid extraction or a quick column. I would choose a dye that has poor water solubility to make for easier purification.

Title: Re: how to add chromophore group in cyclo hexane amine and cyclo hexane alchohole?
Post by: PRAGATI1 on February 14, 2018, 04:51:38 AM

thank you that would work as i need to simply attach a molecule for identification under UV.