[diediemydarlin]

hi, I'm doing an organic prelab for the isolation of caffeine from tea and one of the questions is causing me a little trouble

what are the functional groups involved in the acid base reaction between caffeine and salicylic acid?

i assume the functional group for the acid is COOH, but I have no clue what the base functional group of caffeine would be. can anyone help?

[FeLiXe]

it's definitely a nitrogen and you get an ammonium salt

the one that's most alkaline is probably the one in the 5-circle that forms a double bound. Its lone pair is pointed outward and can be protonated without destroying the aromatic system.

[diediemydarlin]

thanks, so i'm gonna put  (-n-c=n-) well with two single bonds on the first nitrogen but dunno how to do that on here..


                                     

[AWK]

Start from seeing of caffeine structure, eg, on this forum:
http://www.chemicalforums.com/index.php?page=molecules#Caffein