Methanol is better for amino acid couplings in Solid Phase Peptide Synthesis. DCC is also better solvent ast removeshe water formed in the reaction.

Dear Sir,

NMP is best for SPPS., i will give great solvation and its function will somewhat disturb aggregation during the synthesis. DMF, NMP and DMSO are mostly using for SPPS., 

My suggestion NMP is better.  

DMF is better for amino acid coupling reaction. As most resins swell in DMF so that the  more surface area (more functional group ) would be available for bonding.

After reaction you can remove DMF by filtration and washing the residue with Methanol and DCM at least twice.

polar protic or aprotic solvents which makes your substrate soluble.general people are using Methanol, DMF, DMSO same as arun, saraniya and madhukar has suggested.

NMP - Nmethylpyrolidone is very best for SPPS, its giving more swelling and solvation in all condition., DMSO and DMF is second preference, DCM is not good option for SPPS.,

Wish You All A Very Happy New Year 2015

DMF is commonly used, sometimes in combination with DCM (some polystyrene based resins swell better in DCM, but these days DMF alone is just fine- most of the resins are peg- polystyrene type) . You must however use high quality 

Hi Selva,

DMF is highly recommended  for peptide coupling during SPPS and  for initial swelling of resin DCM can be used.

DMF is highly recommended

Your question has been a valid one for a few decades... I am attaching fragments of two pages from a 1994 Springer book, have a look.

DMF IS THE BEST....

DMF is most commonly used because it dissolves reactants, on one side, and swells well the modern resins. In the old days we had to pre-swell polystyrene resins in DCM before adding DMF-dissolved components. NMP dissolves some protected amino acids better, but at the same time more viscous and costly. ACN can be used but again it is more expensive and importantly more volatile (big disadvantage for long synthesis) - may induce crystallization and clog synthesizer tubes (especially if nitrogen is used to agitate the resin) e.t.c. The short answer is DMF#1 (cheap, non-volatile, dissolves reactants, swells resins), but needs to be fresh (fee of DMA) NMP#2 (occasionally, sometimes in combination with DMF - more stable, but also more viscous and costly), ACN#3 - for quick manual couplings (without N2 bubbling), DCM - almost never these days (for coupling I mean). Occasionally I used pyridine or benzene for coupling of unnatural hydrophobic AA, but again, all depends on what you r doing.

I assume that by DMA Vyacheslav meant dimethylamine (not N,N-dimethylacetamide, which it is most commonly referred to). Oh, these acronyms...

Ibtisam Ibtisam

Sir according to my experience

NMP found best - working fine with all amino acids and bit reduce Peptide Aggregation next is common as for DMF.

- Shiab Subhair