Xjyuk

I am writing a lab report for my Chemistry class, and I would like to write a chemical reaction for the following reaction that looks like this.

I have tried the following command to make this reaction.

documentclassarticle
usepackage[utf8]inputenc
usepackagechemfig
usepackage[version=3]mhchem

begindocument
begincenter
scalebox0.6cechemfigO=[:15]-[:69](-[:123,,,2]HO)=_[:357](-[:51,,,1]OH)-[:285](<[:213]O-[:141])-[:339](<[:39,,,1]OH)-[:279]-[:339,,,1]OH + chemfigO=[:19]-[:73]-[:1]-[:289](=[:343]O)-[:217]N(-[:145])-[:271]Br -> chemfigO=[:231]-[:285](-[:339](<[:39,,,1]OH)-[:279]-[:339,,,1]OH)<[:213]O-[:141](=[:195]O)-[:69](-[:357])=[:123]O + chemfigO=[:18]-[:72]--[:288](=[:342]O)-[:216]mcfbelowNH(-[:144]) + chemfigBr-Br
endcenter
enddocument

However, the result is not what I expected. The compounds are not properly lined up.

Can anyone be able to help me with this? Thanks for helping.

I think the code below works with your original code (with slight modifications).

The relevant changes are:
as suggested by @leandriis

• You can remove ce


• You can place the "chemfig"s within schemestart and
  schemestop.



• You can use an arrow defined by the chemfig package arrow(.mid east--.mid
west)




• One suggestion made in the chemfig package is to separate "plusses" and molecules using an invisible zero-length arrow (arrow0[,0]). This causes the molecules and plusses to be treated separately and they end up aligning in a nicer way.



• 
  

  Quoting the chemfig package: 'Therefore, one must stop the compound right after the first molecule with a arrow0[,0] that will draw an invisible, zero-length arrow. In order to vertically center the whole scheme, one must also set the the anchor of the first compound as "west" ... with the second optional argument of the schemestart command'

  
  
  
  • edit: chemfig doc says you need to anchor the first compound to the "west" if you want vertical centering of the scheme. I removed the [west] argument shown below and I don't see a change in vertical alignment, so it does not seem necessary in this case.
  
  


• You can also get rid of mhchem and mol2chemfig (this website is awesome, by the way: https://py-chemist.com/mol_2_chemfig/home it has saved me countless hours)

Here is a screenshot:

documentclassarticle
usepackage[utf8]inputenc
usepackagechemfig
setchemfig+ sep left=1em, + sep right=1em, arrow offset=1em % adjusts spacing around + symbols and the arrow
begindocument
 begincenter
 scalebox0.6
 schemestart[][west] % "west" may be removable here
 chemfigO=[:15]-[:69](-[:123,,,2]HO)=_[:357](-[:51,,,1]OH)-[:285](<[:213]O-[:141])-[:339](<[:39,,,1]OH)-[:279]-[:339,,,1]OH arrow0[,0] + arrow0[,0]
 chemfigO=[:19]-[:73]-[:1]-[:289](=[:343]O)-[:217]N(-[:145])-[:271]Br arrow(.mid east--.mid west) arrow0[,0]
 chemfigO=[:231]-[:285](-[:339](<[:39,,,1]OH)-[:279]-[:339,,,1]OH)<[:213]O-[:141](=[:195]O)-[:69](-[:357])=[:123]O arrow0[,0] + arrow0[,0]
 chemfigO=[:18]-[:72]--[:288](=[:342]O)-[:216]NH(-[:144]) arrow0[,0] + 
 chemfigBr-Br
 schemestop
 
 endcenter
enddocument

Probably the following is closer to the desired output:

documentclassarticle
usepackage[utf8]inputenc
usepackagechemfig
usepackagemol2chemfig

begindocument
scalebox.47
schemestart
chemfigO=[:15]-[:69](-[:123,,,2]HO)=_[:357](-[:51,,,1]OH)-[:285](<[:213]O-[:141])-[:339](<[:39,,,1]OH)-[:279]-[:339,,,1]OH 
+ 
chemfigO=[:19]-[:73]-[:1]-[:289](=[:343]O)-[:217]N(-[:145])-[:271]Br 
arrow-> 
chemfigO=[:15]-[:69](=[:123,,,1]O)-[:357](=[:51,,,1]O)-[:285](<[:213]O-[:141])-[:339](<[:39,,,1]OH)-[:279]-[:339,,,1]OH 
+ 
chemfigO=[:18]-[:72]--[:288](=[:342]O)-[:216]mcfbelowNH(-[:144]) 
+ 
chemfigBr-Br
schemestop

enddocument

Wha I changed in comparison to the original:

• removed the ce command


• placed the whole scheme between startscheme and stopscheme
  


• replaced the mhchem-like arrow -> by the chemfig equivalent arrow->
  


• replaced the code of the furan-trione derivate. For this I copied the code of the dihydroxyfuranone derivate and adjusted the bonds accordingly


• changed the factor of the scalebox to make sure the scheme fits into the textwidth of a standard article class