To a stirred solution of 83.0 g (0.528 mole) of N-(l,l,3,3-tetramethylbutyl) formamide in 11 of DMF was added dropwise, under a nitrogen atmosphere, a solution made up of thionyl chloride (40.3 ml, 0.55 mole) dissolved in 150 ml of DMF. The addition was at such a rate that the temperature did not exceed -50°C. After the addition, the cooling bath was removed momentarily to allow the temperature to increase to -35°C and then it was replaced while 118.0 g (1.11 mole) of sodium carbonate (anhydrous grade) was added. Then the cooling bath was removed and the reaction mixture was diluted with ice-cold water in a separatory funnel and then extracted with pentane. The pentane extract was dried over sodium sulfate and concentrated, and the product distilled to yield 68.4 g (93% yield), b.p. 55.5-56.6°C (11 mm). Infrared spectrum (neat) 2110 c m " 1 (s); nmr (neat) 51.08 [s, 9, C(CH3) 2] , 1.43 [t, 6, J = 2Hz, C(CH3) 2] , 1.58 (t, 2, J = 2.3 Hz, CH2).