The 1 : 1 reaction of 3,5-dimethyl-1,2,4,3,5-trithiadiborolane, 3, with dimethylamine in diethyl ether yielded a mixture of compounds from which only MeB(NMe2)SH, 7, could be separated. In the 1:2 reaction, insoluble Me2NH(MeB(S2)2BMe)HNMe2, 10, could be isolated besides 7 and small amounts of MeB(NMe2)2. In the presence of NMe3 the bis(methyl-dimethylamino-boryl)sulfide, 7 was obtained in good yield. Replacement of HNMe2 by N-methylaniline or piperidine led to the corresponding amino(methyl)sulfhydrido boranes R2N(MeB)SH in moderate yields. tBuNH(MeB)SH results in 61% yield from the treatment of tBu2B2S3 with tBuNH2 in a 1 : 1 ratio.