[MahaMohsen]

hello everyone I am new and need help in understanding what is this abbreviation H in
ethyl acetate (1 : 4) as the eluent to givebin its
enol form as a pale yellow powder (1.56 g, yield: 42%).
1H NMR (CDCl3, 400 MHz) δ( ppm): 17.08 (1H, s), 7.94 (4H, m),
7.48 (2H, d,J = 8.8 Hz), 7.00 (2H, d,J = 8.8 Hz), 6.76 (1H, s),
6.73 (1H, s), 4.19 (2H, t,J = 4.8 Hz), 3.78 (2H, t,J = 4.8 Hz),
3.46 (3H, s), 1.53 (9H, s).

[wildfyr]

(s, 1H) means there is a singlet peak that integrates to 1 proton in the NMR of the pure compound. (m, 2H) means there is a multiplet (a complex splitting or a splitting greater than 5 or so) that integrates to 2 protons. Other notations are d=doublet, t=triplet, bs=broad singlet (usually an acidic proton that can exchange), and combining them gives you notations like dd=doublet of doublets.

[MahaMohsen]

that was so informative, thanks very much