Research Article

An Efficient Method for Synthesis of N-tert-Butyl Amides Using Oxalic Acid Dihydrate in Solvent-Free Condition

Table 1

Amidation of tert-butylacetate or tert-butanol with nitriles using oxalic acid dehydrate.

EntrySubstrateNitrileAmideaTime/hYield %b

(CH3)3COAcC6H5CNC6H5CONHtBu290
(CH3)3COHC6H5CNC6H5CONHtBu2.3088
(CH3)3COAcp-Cl-C6H4CNp-Cl-C6H4CONHtBu292
(CH3)3COHp-Cl-C6H4CNp-Cl-C6H4CONHtBu390
(CH3)3COAcp-Me-C6H4CNp-Me-C6H4CONHtBu288
(CH3)3COHp-Me-C6H4CNp-Me-C6H4CONHtBu2.3085
(CH3)3COAcm-Me-C6H4CNm-Me-C6H4CONHtBu294
(CH3)3COHm-Me-C6H4CNm-Me-C6H4CONHtBu292
(CH3)3COAcp-HO-C6H4CNp-HO-C6H4CONHtBu476
(CH3)3COHp-HO-C6H4CNp-HO-C6H4CONHtBu470
(CH3)3COAcp-NC-C6H4-CNp-tBuNHOC-C6H4CONHtBu4.3092c
(CH3)3COHp-NC-C6H4-CNp-tBuNHOC-C6H4CONHtBu590c
(CH3)3COAcm-NC-C6H4-CNm-tBuNHOC-C6H4CONHtBu4.3088c
(CH3)3COHm-NC-C6H4-CNm-tBuNHOC-C6H4CONHtBu586c
(CH3)3COAcCH2=CHCNCH2=CHCONHtBu366
(CH3)3COHCH2=CHCNCH2=CHCONHtBu460
(CH3)3COAcClCH2CNClCH2CONHtBu3.545
(CH3)3COHClCH2CNClCH2CONHtBu442
(CH3)3COAcNCCH2COOEt tBuNHCOCH2COOEt3.554
(CH3)3COHNCCH2COOEt tBuNHCOCH2COOEt448
(CH3)3COAcCH3CNCH3CONHtBu848
(CH3)3COHCH3CNCH3CONHtBu945

All entries were carried on nitrile (5 mmol), oxalic acid dehydrate (2.5 mmol) and t-BuOAc or t-BuOH (5 mmol) at 70°C. bAll yields refer to isolated products. cNitrile (2.5 mmol) is used.