Reaction #67397

Reaction equation

crotonaldehyde

1-NP

crotonaldehyde

2-Nitropropane

DBU

crotonaldehyde

→

desired product

6-methyl-3,7-dinitrononan-4-ol

Conditions

Workup

1. 1
   OtherA three neck round bottom flask equipped with a stir bar
2. 2
   Othercapped with nitrogen inlet and condenser
3. 3
   workup.ADDITIONThe deep yellow solution was mixed under nitrogen for about thirty minutes
4. 4
   workup.ADDITIONwas done at room temperature and during addition, exotherm of about 12° C.-15° C.
5. 5
   workup.ADDITIONAfter complete addition
6. 6
   workup.STIRRINGto stir at room temperature overnight

Procedure

A three neck round bottom flask equipped with a stir bar, thermocouple, dropping funnel capped with nitrogen inlet and condenser was charged with 2-Nitropropane (50 g, 0.56 mols, 5.0 equivalents) and catalytic amount of DBU. The deep yellow solution was mixed under nitrogen for about thirty minutes. To this mixture was added crotonaldehyde (7.9 g, 9.2 mL, 0.112 moles, 1.0 equivalent) drop-wise over a period of twenty minutes. The addition of crotonaldehyde in this case was done at room temperature and during addition, exotherm of about 12° C.-15° C. was observed. After complete addition, the reaction was stirred at room temperature for 6 hours. At this point, GC analysis showed the absence of crotonaldehyde from the mixture. The reaction was let to stir at room temperature overnight and high-performance liquid chromatography (HPLC) analysis showed the presence of only two peaks which correspond to 1-NP which was in excess and the desired product (1CA+2NP adduct). Excess 1-NP was removed by vacuum distillation and the resulting orange viscous liquid was subjected to hydrogenation. This material was about 37.2 g total weight however it still had some 1-NP remaining.

Source