... (0 Challis, B. C.; Challis, JA In The Chemistry of the ... The product was extracted into CH2C1p The organic layer was washed with brine and dried (NazS04). ... in 72% overall yield from la: mp 80.5-81.5 "C; IR 3100-2850,1625,1570, 1450, 1205 cm-'; 'H NMR 6 8.52 (d, J = 2.8, 1 H ...