CAUTION! Many literature procedures employ NaH in DMF, and this system is often used routinely by research workers as a 'convenient' general purpose strong base. It should be noted, especially when considering scale-up of such reactions, that thermal runaways have been observed with NaH/ DMF, with self-heating beginning at temperatures as low as 26oC in some cases: Chem. Eng. News, 60(28), 5; 60(37), 5 (1982). A similar effect was also noted with N,N-dimethylacetamide. More recently also, incidents have been reported with other dipolar aprotic solvents 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU) and Dimethyl sulfoxide (DMSO): Org. Process. Res. Dev., 7, 1030 (2003).
For a review of sodium hydride-based complex reducing agents, see: Acta Chem. Scand., 44, 274 (1990).
Widely used strong base for the irreversible formation of Na derivatives. If required, the protective oil can be removed by repeated washing and decantation with low-boiling petroleum, see, e.g.: Org. Synth. Coll., 6, 684 (1988), but for many purposes, this is not necessary, and the oil can be removed by incorporating a suitable extraction or washing step in the work-up. There are numerous Organic Syntheses references to reactions using NaH.
Used in the deprotonation of DMSO to form "dimsyl sodium", a useful strong base for e.g. the Wittig reaction: J. Org. Chem., 28, 1128 (1963).